Campus de Botucatu
Instituto de Biociências
Biociências
PG-BGA
Perfil global de expressão de MicroRNAs na próstata ventral
de ratos submetidos à restrição proteica materna: Efeitos
perinatais e reflexos no envelhecimento
MS. FLÁVIA BESSI CONSTANTINO
Tese apresentada ao Instituto de
Biociências, Campus de Botucatu, UNESP, para
obtenção do título de Doutor no Programa de Pós-
Graduação em Biologia Geral e Aplicada, Área de
concentração Biologia Estrutural e Funcional.
BOTUCATU – SP
2021
Campus de Botucatu
Instituto de Biociências
Biociências
PG-BGA
UNIVERSIDADE ESTADUAL PAULISTA “Júlio de Mesquita Filho”
Instituto de Biociências-Departamento de Biologia Estrutural e Funcional
Perfil global de expressão de MicroRNAs na próstata ventral
de ratos submetidos à restrição proteica materna: Efeitos
perinatais e reflexos no envelhecimento
MS. FLÁVIA BESSI CONSTANTINO
PROF. DR. LUIS ANTONIO JUSTULIN JUNIOR
PROF. DR. ROBSON FRANCISCO CARVALHO
Tese apresentada ao Instituto de
Biociências, Campus de Botucatu, UNESP, para
obtenção do título de Doutor no Programa de Pós-
Graduação em Biologia Geral e Aplicada, Área de
concentração Biologia Estrutural e Funcional.
BOTUCATU – SP
2021
3
Ficha catalográfica
4
A minha Família, Namorado e Amigos...
Dedico
5
Agradecimentos
Ao Dr. Luis Antonio Justulin Junior, pelo conhecimento compartilhado, pela
confiança em meu trabalho, por sempre acreditar em meu potencial e me apoiar sempre,
sem você não teria chegado tão longe. Obrigada por me receber de braços abertos no
laboratório e me tornar uma amante da pesquisa.
Ao Laboratório de Matriz Extracelular (Labmec) e agregados, pelo
companheirismo, conhecimento compartilhado, por todo apoio em momentos difíceis e
pelas risadas.
Ao Miguel Antunes, por sempre acreditar em mim, me fazer buscar sempre
mais, por todo apoio e carinho. Obrigada por além de ser meu técnico, ser meu amigo.
A minha Família, por sempre serem meu porto seguro e me fazerem alçar voos
mais altos. Obrigada por sempre me apoiarem e estarem sempre presentes mesmo
longe.
Ao Renato Colenci. por sempre estar ao meu lado, por me fazer uma pessoa
melhor, por sempre me ouvir e dar conselhos, por fazer meus dias mais felizes. Obrigada,
sem o seu apoio não teria conseguido.
As agencias de fomento FAPESP (processo nº2017/08716-6) e CAPEs pelo
suporte financeiro.
E a todos que contribuíram de alguma forma para o meu crescimento e para
a confecção desta tese.
6
"A tarefa não é tanto ver aquilo que ninguém viu, mas pensar o que
ninguém ainda pensou sobre aquilo que todo mundo vê."
(Arthur Schopenhauer)
7
Sumário
Lista de abreviaturas ............................................................................................ 9
Lista de Figuras .................................................................................................. 11
Lista de tabelas .................................................................................................. 12
Resumo .............................................................................................................. 14
Capítulo 1: Revisão Bibliográfica ........................................................................ 15
1.1 Programação Fetal .................................................................................... 15
1.2 Programação Fetal e baixa ingesta de Proteína ....................................... 16
1.3 Próstata e a programação Fetal por baixa ingesta de proteína ................. 18
1.4 Mecanismos Epigenéticos Envolvidos na Programação Fetal .................. 22
Referencias ..................................................................................................... 27
Capítulo 2: MiRNAome integrative analysis reveals molecular mechanisms
associated with development of PCa in the offspring subjected to maternal low protein
diet. ............................................................................................................................... 28
Abstract ........................................................................................................... 29
1.0 Introduction ............................................................................................ 30
2.0 Material and Methods ............................................................................. 32
3.0 Results ................................................................................................... 39
4.0 Discussion .............................................................................................. 49
5.0 Referencie .............................................................................................. 54
Capítulo 3: Prediction of non-canonical routes for SARS-CoV-2 infection in human
placenta cells – submitted to Science Signaling. ........................................................... 67
Abstract ........................................................................................................... 69
1. Introduction ................................................................................................. 70
2. Results ........................................................................................................ 72
8
3. Discussion ................................................................................................... 74
4. Materials and Methods ................................................................................ 77
References ...................................................................................................... 79
9
Lista de abreviaturas
ACE2: angiotensin-converting enzyme 2
BPH: Benign prostatic hyperplasia
CaP: câncer de próstata
CEEA: Comissão de Ética na Experimentação Animal
COBEA: Colégio Brasileiro de Experimentação Animal
COVID-19: coronavirus disease 2019
CTR: Controle
CTSL: cathepsin L
CUG: complexo urogenital
DAG: distância ano genital
DEGs: differentially expressed genes
DG: Dia gestacional
DM2: Diabetes mellitus do tipo 2
DNMT: DNA metil transferases
DOHaD: Developmental Origins of Health and Disease
DPN: dias pós-natal
DPP4: dipeptidyl peptidase 4
GEO: Gene Expression Omnibus
GLLP: Gestational and lactational low protein diet
GSEA: Gene Set Enrichment Analysis
GSH: Glutationa Peroxidase
HAC: histona acetilase
HDAC: deacelilase
HE: hematoxilina-eosina
HPB: hiperplasia prostática benigna
IGF-1: Fator de crescimento semelhante à insulina tipo 1
KOBAS: KEGG Orthology Based Annotation System
LPD: Low protein diet
10
LR: Likelihood Ratio
miRNA: microRNAs
mRNAS: RNA mensageiro
ORF8: open reading frame 8
PA: lobo anterior
PCA: análise de componentes principais
PCa: Prostate cancer
PDL: lobo dorsolateral
PF: Programação Fetal
PND: Postnatal day
PPI: protein-protein interactions
PTHrP: parathyroid hormone-related protein
PV: lobo ventral
RBD: receptor-binding domain
RTKs: receptores de tirosina-quinase
SARS-CoV-2: severe acute respiratory syndrome coronavirus 2
Shh: Sonic hedgehog
SOD: Superóxido Dismutase
Tbx3: T-box transcription factor
TCGA: The Cancer Genome Atlas
TMPRSS2: cellular transmembrane serine protease 2
USG: seio urogenital
ZIKV: Zika virus
11
Lista de Figuras
Capítulo 1
Figura 1. Organização anatômica da próstata.
Figura 2. Estágios do desenvolvimento da próstata de rato e humano.
Figura 3. Esquema da glândula prostática. Imagem de Mateus Betta de Oliveira
Figura 4. Esquema da biogênese dos miRNAs.
Capítulo 2
Figure 1. The GLLP group has lower weight, late prostate development and a higher level of testosterone
and estrogen.
Figure 2. MiRNAs differentially expressed in the GLLP group have predicted targets related to interesting
enriched pathways.
Figure 3. GLLP group presents some deregulated miRNAs in common with prostate cancer patients.
Figure 4. Expression of mir-33-5p using the RT-qPCR technique in different organs showing the lower
expression in prostate, testicle and liver and a higher level in adrenal gland in GLLP group when compared
to CTR.
Figure 5. miR-33a-5p overexpression causes low levels of cell viability
Figure 6. The predicted mir-33-5p targets are involved in all selected pathways and with prostate cancer.
Capítulo 3
Figure 1. The expression landscape of human placenta proteins potentially interacting with
SARS-CoV-2.
Figure 2. Single-cell analysis of the human placenta indicates potential non-canonical routes of
SARS-CoV-2.
Supplementary Figure 1. Gene expression profile of gestational trimesters and its potential to
interact with SARS-CoV-2 proteins.
Supplementary Figure 2. Gene expression of ACE2, TMPRSS2, CTSL, DPP4, DAAM1, and
PAICS in scRNA-seq of fetal tissues.
12
Lista de tabelas
Capítulo 1
Capítulo 2
Table 1. Rat and prostate weight and stereological results.
Supplementary Table 1. Differentially expressed miRNAs in prostate tissue between CTR group
and GLLP group (Log2FC >= |0.4|; FDR< 0.05).
Supplementary Table 2. Target prediction analysis of the differentially expressed miRNAs
generated in the mirwalk (http://mirwalk.umm.uni-heidelberg.de/)
Supplementary Table 3. Differentially expressedm RNAs and proteins in prostate tissue between
the CTR GLLP groups of rats on the postnatal day 21 (mRNAs-Log2FC> = |0.66|; p value <0.05.
Proteins-Log2FC> = |1|; p value <0.05).
Supplementary Table 4. Integrative analysis combining the prediction of the miRNAs targets
with differentially expressed mRNAs and proteins, taking into account inverted log2 fold change
values.
Supplementary Table 5. Functional enrichment analysis x up-regulated targets resulting from
the integrative analysis using the Kobas tool (http://kobas.cbi.pku.edu.cn/kobas3/?t=1)
[DOI:10.1093/nar/gkr483]
Supplementary Table 6. Functional enrichment analysis x down-regulated targets resulting from
the integrative analysis using the Kobas tool (http://kobas.cbi.pku.edu.cn/kobas3/?t=1)
[DOI:10.1093/nar/gkr483]
Supplementary Table 7. Differentially expressed miRNAs in prostate tissue between CTR and
cancer groups (Log2FC >= |0.4|; FDR< 0.05) from The Cancer Genome Atlas (TCGA).
Supplementary Table 8. Deregulated miRNAs shared by rats and patients with prostate cancer.
Capítulo 3
Supplementary Table 1. Differentially expressed genes in placenta tissue during the gestation
(1º trimester x 2º trimester and 1º trimester x 2º trimester; Log2FC >= |0.5|; FDR< 0.05).
Supplementary Table 2. Functional enrichment analysis generated in the Metascape tool
(https://metascape.org) [DOI: 10.1038/s41467-019-09234-6] for each cluster generate for
placenta gene expression during gestation.
13
Supplementary Table 3. Functional enrichment analysis list generated in the Metascape tool
(https://metascape.org) [DOI: 10.1038/s41467-019-09234-6] for DEGs in the placenta tissues (1º
trimester x 2º trimester and 1º trimester x 2º trimester.
Supplementary Table 4. Human-SARS-CoV Interactome based on the in silico computational
framework P-HIPSTer (http://phipster.org/).
Supplementary Table 5. Human-ZIKA Interactome based on the in silico computational
framework P-HIPSTer (http://phipster.org/).
Supplementary Table6. The Human-SARS-CoV interactome obtained in the P-HIPSTer
(http://phipster.org/) for placenta.
Supplementary Table 7. The Human-ZIKA interactome obtained in the P-HIPSTer
(http://phipster.org/) for placenta.
Supplementary table 8. Human-SARs Interactome based on literature.
14
Resumo
Nas últimas décadas, foi observado aumento na incidência de câncer na população.
Estudos mostram que o câncer pode se originar de insultos sofridos por indivíduos
durante a vida intrauterina, visto que que este período é caracterizado pela capacidade
do embrião/feto em se adaptar às mudanças ambientais, alterando a expressão gênica
por mecanismos pós-transcricionais. Já foi demonstrado que a restrição proteica materna
promove a carcinogênese da próstata em ratos idosos; No entanto, há falta de
informações sobre o mecanismo molecular envolvido nesse processo. Assim,
objetivamos identificar os possíveis microRNAs desregulados em ratos jovens
programados e localizar seus possíveis alvos associados à carcinogênese da próstata.
Para isso, ratos machos Sprague Dawley nascidos de mães alimentadas com dieta
padrão (17% de proteína), grupo controle (CTR), ou dieta pobre em proteínas (6% de
proteína), grupo gestational and lactational low protein diet (GLLP), durante a gestação
e lactação foram sacrificados no dia pós-natal 21. O sangue foi coletado para analises
hormonais e a próstata ventral foi processada para morfologia e por sequenciamento,
HigSeq -2500 Illumina, para determinar o perfil do microRNoma. Dados de
sequenciamento de miRNAs de pacientes com câncer de próstata, oriundos do the
cancer genome atlas (TCGA), foram reanalisados para comparação com os resultados
de ratos. Além disso, foi realizada a transfecção do miR-33 em células PNT-2 para avaliar
a expressão de seus alvos e a viabilidade celular após tratamento através da técnica de
MTT. Assim, foi observado atraso no desenvolvimento da próstata ventral e aumento
dos níveis de testosterona e expressão de estrogênio em ratos GLLP. Além disso, 20
miRNAs foram identificados como diferencialmente expressos, 6 down regulados e 14
up regulados. Os resultados de enriquecimento para miRNAs down regulados estão
relacionados às vias do câncer e da angiogênese, enquanto os miRNAs up regulados
estão enriquecendo vias de retículo endoplasmático e de carcinoma. A reanálise do
sequenciamento de miRNA de TCGA revelou 7 em comum com o grupo GLLP. Um deles
é o miR-33 que, além de ser down regulado na próstata, também é desregulado no
testículo, na glândula adrenal e no fígado, dados gerados através do RTq-PCR. Sua
supra expressão nas células transfectadas causou uma diminuição na viabilidade celular
e seu alvo, CYP1B1, é uma enzima importante no metabolismo do estrogênio, que pode
levar à carcinogênese mediada por mudanças nos níveis hormonais e transformação do
estradiol. Concluímos que o miR-33 é um alvo importante para explicar as alterações
causadas pela LPD materna podendo, ser considerado um considerável biomarcador por
ser desregulado em vários órgãos analisados.
Palavras-Chave: Programação Fetal, Câncer de Próstata e MicroRNAs
15
Capítulo 1: Revisão Bibliográfica
1.1 Programação Fetal
A boa nutrição é fundamental para a manutenção da saúde, sendo que nenhum
país pode alcançar a cobertura universal de saúde sem investir em ações que garantam
a nutrição essencial de sua população. A má alimentação é uma das maiores causas de
comorbidade e morte no mundo, mais que o Tabaco e a hipertensão (AFSHIN et al.,
2019). Além disso, está relacionada com o aumento do risco de doenças infecciosas,
como pneumonia, diarreia, sarampo e tuberculose, assim como o aumento de doenças
no coração, câncer, diabetes além de mortes neonatais (BLACK et al., 2013; CAULFIELD
et al., 2004; HOFFMAN et al., 2020; PELLETIER et al., 1995; PORTELA et al., 2021).
Em 2017, 56% das mortes de crianças com menos de 5 anos foram atribuídas à má
nutrição materna (INSTITUTE FOR HEALTH METRICS AND EVALUATION (IHME),
2018). Estudos vem mostrando que a má nutrição materna pode estar relacionada com
o aparecimento de doenças crônicas na vida adulta dos filhos, mostrando que a origem
dessas doenças pode se dar a partir de insultos sofridos durante o período
embrionário/fetal. Esse processo ficou conhecido como Programação Fetal (PF)
(BARKER, 2007; MERICQ et al., 2017; PINHO et al., 2014; SANTOS et al., 2019).
Um dos primeiros pesquisadores a estudar a PF foi Ravelli e colaboradores em
1976 (RAVELLI; STEIN; SUSSER, 1976). Eles fizeram um estudo coorte retrospectivo
com 300.000 pessoas que foram expostas à fome holandesa durante o período pré-natal
e logo após o nascimento. A Fome Holandesa Aconteceu em 1944-45 durante a
Segunda Guerra mundial que por conta da invasão alemã e pelo congelamento do mar
impedindo a chegada de navios, a população ficou sem abastecimento de comida e
passou a ter uma alimentação de 400-800 calorias diariamente. Ravelli e colaboradores
(1976) observaram que se o feto foi exposto à restrição alimentar durante o último
trimestre de gestação, ele apresentava uma menor probabilidade de obesidade por esse
período ser um período crítico para o desenvolvimento de tecido adiposo. Porém, se a
restrição alimentar acomete o feto durante a primeira metade da gestação o quadro
muda, tendo maior probabilidade de obesidade pois a restrição alimentar afeta o centro
hipotalâmico responsável pela saciedade e crescimento fetal. Após este período, a
16
alimentação deixou de ser restrita e levou a um excesso de gordura no organismo o que
ocasiona um maior crescimento e aumento de células adiposas (RAVELLI; STEIN;
SUSSER, 1976).
Além de Ravelli, o epidemiologista inglês David Barker também encontrou
resultados pertinentes. Em 1989, BARKER e seus colaboradores relacionaram o baixo
peso ao nascimento com mortes por doenças cardíacas na vida adulta (BARKER et al.,
1989). Em outro estudo demonstraram que pacientes com baixo peso ao nascimento,
associado com maior tamanho de placenta apresentam maior pressão arterial na vida
adulta (BARKER et al., 1990). Além disso, estudos vem mostrando que a restrição
alimentar materna pode levar a modificação do metabolismo de colesterol, afetar níveis
de insulina podendo iniciar um estado de resistência à insulina e levar ao Diabetes
mellitus do tipo 2 (DM2) na vida adulta (BARKER et al., 1993; BARKER, 1997). Por
apresentar baixo peso ao nascimento elas passam por um período de crescimento
acelerado (catch-up growth) (FITZHARDINGE; STEVEN, 1972), o que contribui para
aumentar o risco de sobrepeso e obesidade já na infância. Ainda não se sabe quais
fatores determinam o crescimento acelerado no período pós-natal. No entanto, alguns
estudos sugerem que esse tipo de crescimento pode estar associado a fatores inerentes
ao período intrauterino e, consequentemente, as características e hábitos maternos
durante a gravidez.
Através destes e outros estudos se originou a Hipótese de Barker, e com o passar
do tempo, a ideia de programação fetal se estendeu para outros períodos, além do
período fetal, e não ficou restrita ao processo de doença, mas à saúde também,
originando a denominada Developmental Origins of Health and Disease (DOHaD)
(GLUCKMAN; HANSON; BUKLIJAS, 2010; SCHULZ, 2010).
1.2 Programação Fetal e baixa ingesta de Proteína
A organização alimentar e agrícola das nações unidas mostra que em países da
Europa, Oceania e América do Norte as pessoas se alimentam em média de 100 gramas
(g) de proteínas por dia. Os países do sul da Ásia, África Subsaariana e América do Sul
tem uma média de 50 a 90 g de proteína. No entanto, a maioria dos países de baixa
renda está dentro da faixa entre 30-60 g dia (UNITED NATIONS FOOD AND
17
AGRICULTURAL ORGANIZATION (FAO), 2020). A porcentagem mínima de proteína
recomendada pela organização mundial de saúde é de no mínimo 0,8 g/dia de proteína
por quilograma de peso para um indivíduo adulto, sendo que para gestantes e lactantes
essa recomendação aumenta. Assim, um dos grandes fatores que levam a má nutrição
é a ausência de proteína na alimentação, seja este um fator cultural ou socioeconômico.
Além de que, diversos modelos tem sido utilizados para melhor conhecimento dos efeitos
da PF, sendo o mais utilizado a dieta hipoproteica oferecida durante a gestação e
lactação, principalmente utilizando-se de modelos com animais de laboratório
(COLOMBELLI et al., 2017; DE BRITO ALVES et al., 2016; OZANNE; HALES, 2004;
PINHO et al., 2014). Segundo o Instituto Americano de Nutrição para dietas de ratos o
indicado é que a ração tenha pelo menos 12% de proteína. A maioria dos estudos com
programação fetal por restrição proteica utiliza valores de 6-8% de proteína para os
animais restritos contra 20-22% para os animais controle.
Estudos vem mostrando que a prole de mãe que se alimenta com baixa
quantidade de proteína tem menor peso ao nascimento, seguido pelo conhecido catch-
up growth (crescimento acelerado), resistência à insulina e DM2 na vida adulta,
diminuindo a expectativa de vida destes individuos (EMBLETON et al., 2016;
MCMILLEN; ADAM; MÜHLHÄUSLER, 2005; PETRY et al., 2001). Quando a dieta
hipoproteica vem seguida de um estilo de vida desfavorável como o consumo de uma
dieta hiperlipídica, sedentarismo e consumo de alimentos processado, os quadros
clínicos são agravados (DEARDEN; OZANNE, 2014; KWON et al., 2012; OZANNE;
HALES, 2004).
O consumo de uma dieta hipoproteica também exibe resistência à insulina em
tecido adiposo (TARRY-ADKINS et al., 2015), fibrose e esteatose hepática e um
processo inflamatório aumentado (KWON et al., 2012; TARRY-ADKINS et al., 2016). Há
redução de crescimento de diferentes órgãos, dislipidemia, elevação da pressão sistólica
(hipertensão), disfunção renal e vascular (BLACK et al., 2015; DE BRITO ALVES et al.,
2016; FALCÃO-TEBAS et al., 2012; LEANDRO et al., 2012). Acarreta menor número de
néfrons no rim (HABIB et al., 2012; SENE et al., 2013), menor quantidade de células
beta-pancreática e de ilhotas de Langerhans no pâncreas (CALZADA et al., 2016; DAHRI
18
et al., 1991), proporção alterada entre os tipos celulares e aumento de estresse oxidativo
(BURNS et al., 1997; TARRY-ADKINS et al., 2016; VEGA et al., 2016), menor número
de neurônios que controlam o apetite no hipotálamo (PLAGEMANN et al., 2000) e menor
número de alvéolos pulmonares (ZANA-TAIEB et al., 2013). Em conjunto, estes dados
demonstram que o status nutricional durante o desenvolvimento pré e pós-natal alteram
o metabolismo da prole e a morfofisiologia de diferentes órgãos e sistemas, sendo que
as consequências podem ser observadas tanto ao nascimento, como a longo prazo.
1.3 Próstata e a programação Fetal por baixa ingesta de proteína
A próstata é uma glândula exócrina acessória do sistema genital cujo
desenvolvimento e homeostasia encontram-se sob controle androgênico (BIANCARDI et
al., 2017; CUNHA et al., 1985; ZAVIACIC; ABLIN, 2000). Ela secreta um complexo
proteolítico composto por fosfatase ácida, ácido cítrico, fibrinolisina, enzimas específicas
e outros componentes do fluido seminal que auxiliam no sucesso reprodutivo
(AUMÜLLER; SEITZ, 1990; MARKER et al., 2003).
A próstata está localizada no compartimento subperitoneal, anterior ao reto e
inferior à bexiga urinaria (SCHAUER; ROWLEY, 2011). Estudos mostram que ela possui
três zonas morfologicamente distintas: (1) zona periférica (região com maior
acometimento de câncer), (2) zona de transição e (3) zona central, além de uma região
não glandular, o estroma fibromuscular anterior (Figura1.A) (LOWSLEY, 1912).
Já a próstata de roedores apresenta quatro lobos: lobo anterior (PA), lobo ventral
(PV), lobo dorsal e lobo lateral, sendo os dois últimos também chamados de lobo
dorsolateral (PDL) (Figura 1B). Cada lobo é localizado em posição específica em torno
da uretra (LOWSLEY, 1912). Se fizermos uma homologia com a próstata humana, o lobo
anterior corresponde á zona central da glândula e o lobo dorsolateral a zona periférica.
O lobo ventral não apresenta nenhuma homologia com a próstata humana, porém, é o
mais responsivo a andrógeno, de rápido e fácil acesso, além de geralmente não
desenvolver prostatite, por essas e outras razões, este é o lobo mais estudado (ROY-
BURMAN et al., 2004).
19
Figura 1. Organização anatômica da próstata. A. Próstata humana. B. Próstata de camundongo. Imagem A
retirada do site https://www.urologyhealth.org/urologic-conditions/prostatitis-(infection-of-the-prostate)
Acesso:03/08/2020 e imagem B adaptada de (AHMAD; SANSOM; LEUNG, 2008).
Nos camundongos e ratos, o desenvolvimento prostático tem início por volta do
17º dia de gestação e, no humano entre 9-10 semanas de gestação (WELSH et al.,
2008). A próstata se desenvolve através de um processo conservador, denominado de
morfogênese de ramificação, onde pequenos brotos se projetam a partir do epitélio do
seio urogenital (USG). Particularmente no rato, a síntese de testosterona pelos testículos
fetais tem início entre os dias 13-14 da gestação (DG) (WILSON et al., 1983). Em
resposta aos andrógenos, o epitélio do UGS passa a expressar Sonic hedgehog (Shh),
que por sua vez estimula expressão do gene homeobox Nkx3.1 no DG15.5, dois dias
antes de surgirem os primeiros brotos prostáticos (WILHELM; KOOPMAN, 2006). Depois
do nascimento, ocorre alongamento dos brotos e início da morfogênese com a formação
dos ductos glandulares (PRINS et al., 1992), visto que em ratos a maior parte do
desenvolvimento acontece durante os primeiros 15 dias pós-natal (DPN) enquanto que,
em humanos o desenvolvimento é quase todo durante a vida intrauterina (TIMMS;
MOHS; DIDIO, 1994). Em ambos, esse processo se estende até que a maturidade sexual
seja atingida com a puberdade (MARKER et al., 2003) (Figura 2).
https://www.urologyhealth.org/urologic-conditions/prostatitis-(infection-of-the-prostate)
20
Figura 2. Estágios do desenvolvimento da próstata de rato e humano. Imagem de (PRINS; PUTZ, 2008).
A próstata apresenta uma complexa rede de ducto, que nada mais é do que uma
região de lúmen revestido por células epiteliais secretoras, que possuem polaridade
apical-basal e são responsáveis pela síntese e secreção de proteínas e fluidos para o
lúmen prostático (MARKER et al., 2003). As células epiteliais se organizam de forma
a dar a característica histológica de glândula túbulo-alveolar composta, o seu epitélio
usualmente é colunar alto, porém pode haver alteração dependendo do estado
funcional da glândula (DERMER, 1978) (Figura 3). O componente estromal engloba
todos os elementos celulares e extracelulares que estão fora da lâmina basal epitelial
como a camada fibromuscular que cerca a glândula. Além da camada muscular, o
estroma também apresenta fibroblastos, vasos sanguíneos e os pericitos associados,
células imunitárias, terminações nervosas e vasos linfáticos, os quais são incorporados
a uma matriz extracelular colagenosa (AUMÜLLER; SEITZ, 1990).
21
Figura 3. Esquema da glândula prostática. Imagem de Mateus Betta de Oliveira.
Portanto, além de sua importância para a fertilidade, nos últimos anos a próstata
tem despertado grande interesse médico-científico pela alta incidência de distúrbios,
principalmente a hiperplasia prostática benigna (HPB) e o câncer de próstata (CaP)
(DASGUPTA; SRINIDHI; VISHWANATHA, 2012). O CaP é a terceira causa de óbitos
por câncer entre homens no mundo e é o segundo mais incidente (Tabela 1)(“Global
Cancer Observatory” acess:26/05/2021).
Frente a isso e considerando que o período intrauterino é caracterizado pela
capacidade do embrião/feto em se adaptar às mudanças ambientais, alterando a
expressão gênica por mecanismos pós-transcricionais, vários autores demonstraram o
impacto negativo de alterações do ambiente intrauterino sobre o desenvolvimento e
fisiologia prostática. Ratos do DPN 21 submetidos a restrição proteica materna
apresentaram menor peso prostático, com diminuição do tamanho nos ácinos da PDL
(RAMOS et al., 2010). Pinho et al. (2014) também observaram atraso no
desenvolvimento prostático associado com diminuição de proliferação celular na prole
de animais submetidos ao mesmo protocolo e analisados no DPN 1.
22
Tabela 1. Distribuição proporcional dos dez tipos de câncer mais incidentes estimados para 2020 em homens,
exceto pele não melanoma, (https://gco.iarc.fr/) acesso: 26/05/2021.
Nosso grupo de pesquisa demonstrou recentemente que a restrição proteica
perinatal reduziu o processo de angiogênese prostática, levando a menor troca de
moléculas entre os vasos e os compartimentos epitelial e estromal, impactando
negativamente o desenvolvimento glandular. Estes resultados foram relacionados à
menor concentração de testosterona, insulina e fator de crescimento semelhante à
insulina tipo 1 (IGF-1) circulante, com efeitos negativos sobre os índices de proliferação
e diferenciação do epitélio glandular (COLOMBELLI et al., 2017). Mais recentemente,
observamos que ratos com 540 dias de idade que sofreram restrição proteica na
gestação e lactação apresentaram maior incidência de lesões prostáticas, com aumento
na incidência de neoplasia intraepitelial (SANTOS et al., 2019). Estes dados demonstram
que a restrição proteica materna é suficiente para desencadear um aumento de
incidência de lesões prostáticas na prole durante o envelhecimento. Entretanto, os
mecanismos moleculares envolvidos neste processo ainda não foram totalmente
esclarecidos.
1.4 Mecanismos Epigenéticos Envolvidos na Programação Fetal
O período de desenvolvimento intrauterino é caracterizado pela grande
plasticidade e habilidade do embrião/feto em responder a alterações ambientais (dieta,
https://gco.iarc.fr/
23
estresse e hormônios), modulando a expressão de genes envolvidos com o controle da
proliferação e diferenciação celular em uma fase de morfogênese de órgãos e sistemas
vitais (BURTON; FOWDEN; THORNBURG, 2016). Entretanto, pouco se sabe sobre os
agentes envolvidos neste processo e as consequências para a prole. Nos últimos anos,
mecanismos epigenéticos tem sido apontado como os principais moduladores da
expressão gênica envolvidos em várias formas de programação fetal (JOUBERT et al.,
2016), uma vez que mudanças ambientais podem alterar de forma persistente
marcadores epigenéticos e desencadear respostas fenotípicas que afetam a estrutura e
o funcionamento de órgãos de maneira permanente (SINCLAIR et al., 2007;
WATERLAND; JIRTLE, 2003).
O termo "epigenética" foi utilizado pela primeira vez por Waddington
(WADDINGTON, 2012) para definir as interações dos genes e o ambiente que levam ao
desenvolvimento de um fenótipo. A partir de então, outros autores referem-se à
epigenética como mudanças reversíveis e herdáveis no genoma capazes de afetar a
expressão gênica e o fenótipo celular, sem, entretanto, alterar a sequência primária de
nucleotídeos do DNA (DEANS; MAGGERT, 2015; FERNANDEZ-TWINN;
CONSTÂNCIA; OZANNE, 2015). Estudos em modelo de programação fetal por restrição
proteica tem demonstrado a participação de mecanismos epigenéticos e, apesar destes
mecanismos terem sido bastante estudados no contexto do desenvolvimento
embrionário e da biologia do câncer, o conhecimento sobre como a epigenética contribui
para a programação fetal ainda é escasso. Isto se torna particularmente importante, uma
vez que alterações em fatores ambientais, como a nutrição materna impacta fortemente
os níveis de expressão gênica na prole (HEERWAGEN et al., 2010). Os principais
mecanismos de regulação epigenética incluem metilação de DNA, por enzimas DNA
metil transferases (DNMT), modificação pós-transcricional de histonas pelas enzimas
histona acetilase (HAC) ou deacelilase (HDAC), além da participação de RNAs não
codificantes, dentre estes, os microRNAs (miRNA) que também tem sido descritos no
mecanismo epigenético de regulação da expressão gênica (ALLIS; JENUWEIN, 2016;
HEERWAGEN et al., 2010).
24
miRNAs são uma classe de pequenos RNAs não codificantes com
aproximadamente 22 nucleotídeos que têm como função a regulação pós-transcricional
da expressão de genes. Os miRNAs se originam de uma longa molécula primária
transcrita de um precursor pela RNA polimerase II em seu determinado gene loci com
formato hairpin chamado de miRNA primário (pri-miRNA). A transcrição do pri-miRNAs
pode ser controlado por fatores transcricionais da RNA Pol II (p53, Proteína de
determinação de MYC, ZEB1 e ZEB2 e MYOD1) e por regulação epigenética (metilação
de DNA e modificações de histonas)(CAI; HAGEDORN; CULLEN, 2004; DAVIS-
DUSENBERY; HATA, 2010; KIM; HAN; SIOMI, 2009; KROL; LOEDIGE; FILIPOWICZ,
2010; LEE et al., 2004). Os pri-miRNAs passam por passos de maturação, ainda no
núcleo. A Drosha, que possui dois domínios o RNase III (RIIIDs) e o dsRNA-binding
(dsRBD), juntamente com seu cofator essencial a proteína DiGeorge Syndrome Critical
Region Gene 8 (DGCR8) formam um complexo chamado Microprocessador (DENLI et
al., 2004; GREGORY et al., 2004; HAN et al., 2004; LANDTHALER; YALCIN; TUSCHL,
2004) que inicia a maturação cortando a stem–loop para liberar um pequeno RNA em
forma de hairpin com ~ 65 nucleotídeos de comprimento (pre-miRNA) (LEE et al., 2003).
Após o processamento da Drosha, o pre-miRNA é exportado no citoplasma através de
um complexo formado pela proteína Exportin 5 (EXP5), proteína nuclear de ligação GTP-
RAN e o pre-miRNAs (BOHNSACK; CZAPLINSKI; GORLICH, 2004; LUND et al., 2004;
YI et al., 2003). Após a passagem pelo complexo de poros nucleares, o GTP é hidrolisado
sendo o complexo desmontado e ocorrendo a liberação do pre-miRNA no citoplasma,
onde a maturação pode ser completada. No citoplasma o pre-miRNA é processado pela
Dicer, uma outra enzima RNase III, que juntamente com a TAR RNA-binding protein
(TRBP) reduz o pre-miRNA para uma fita dupla de aproximadamente 20 nucleotídeos
que agora é denominado de miRNA maduro. Uma das fitas do pequeno duplex de RNA
gerado pelo Dicer se liga com uma proteína AGO para formar um complexo efetor
chamado complexo de silenciamento induzido por RNA (RISC) (HAMMOND et al., 2001;
MOURELATOS et al., 2002; TABARA et al., 1999). Assim, os miRNAs funcionam como
um guia, unindo-se ao seu alvo, enquanto a proteína AGO funciona como um recrutador
de fatores que induzem a repressão translacional dos mRNA (Figura 3).
25
Figura 4. Esquema da biogênese dos miRNAs. (WINTER et al., 2009)
As primeiras publicações referentes a miRNAs foram publicadas em 1993 por
Victor Ambros e Gary Ruvkun. Foram dois artigos publicados na mesma edição da Cell,
cada um descrevendo o seu trabalho. Victor descreveu o primeiro miRNA, mesmo essa
terminologia vindo a ser usada oito anos depois (LEE; FEINBAUM; AMBROS, 1993) e
Gary descreveu o mecanismo regulatório do mRNA (lin-4 regulando lin-14) (WIGHTMAN;
HA; RUVKUN, 1993). Desde então houve uma crescente no número de publicações,
sendo que nos últimos 10 anos foram publicados mais de 100 mil estudos relacionados
com miRNAs. Esses estudos são variados, porém uma grande parcela é relacionando a
atuação dos miRNAs nos diversos tipos de canceres (CHAKRABORTY et al., 2020; MIN
et al., 2014; PARASRAMKA et al., 2012; PIAN et al., 2020). Um dos pontos estudados é
a expressão dos pri-miRNAs. Os genes dos miRNAs, muitas vezes, são localizados em
regiões que possuem uma maior probabilidade de serem deletadas, amplificadas ou
translocados (CALIN et al., 2004). Essa característica pode causar a desregulação da
expressão dos pri-miRNAs e promover a iniciação ou progressão do câncer (ZHANG et
26
al., 2006). Esta desregulação pode ser causada pelo próprio câncer, que aumenta a
expressão de fatores transcricionais e com isso desregular a expressão dos pri-miRNAs
(BOMMER et al., 2007; LIN; GREGORY, 2015; RAVER-SHAPIRA et al., 2007). Outro
ponto importante é o complexo Microprocessador que frequentemente está desregulado
no câncer (MURALIDHAR et al., 2011; SUGITO et al., 2006). Mas as alterações podem
ocorrer também no momento da exportação para o citoplasma (MELO et al., 2010) e na
proteína Dicer (KUMAR et al., 2009). Assim, as alterações nos níveis de expressão dos
miRNAs veem sendo muito estudas e correlacionadas com o surgimento ou progressão
de diversos tipos de câncer.
Fatores dietéticos também estão sendo relacionados com a desregulação dos
miRNAs induzidas pela nutrição materna durante a gestação e ou lactação que afeta a
prole. A alta ingestão materna de gordura durante a gestação e lactação modulou o
metabolismo lipídico hepático e a expressão de microRNA-122 (miR-122) e microRNA-
370 (miR-370) na prole (BENATTI et al., 2014) além de alterar a expressão hepática da
insulina como o fator de crescimento 2 e microRNAs importantes na prole adulta (miR-
503, miR-379, miR-770-3p, miR-369-3p, miR-197, miR-21, miR-328, miR-471, miR-207,
miR-667 up regulados e miR-410, miR-804, miR-323-5p, let-7c, miR-302a, miR-711,
miR-26a, miR-122, miR-216b, miR-294, miR-185, miR-192, miR-29a, miR-194, miR-145,
miR-126-3p, miR-762, miR-16, miR-1224, miR-22, miR-30c-2, miR-494, miR-483 down
regulados)(ZHANG et al., 2009). Já a baixa ingestão de proteína na última semana de
gravidez é crítica e suficiente para induzir efeitos na homeostase da glicose, causando
alterações permanente no conjunto específico de miRNAs que podem contribuir para a
vulnerabilidade geral de descendência para a obesidade, resistência à insulina e
diabetes tipo 2 (ALEJANDRO et al., 2020). Alguns estudos mostram que a LPD maternal
causa desregulação de miRNAs que causam mudanças metabólicas, inflamação
crônica, aumento da pressão sanguínea e alterações na morfologia do coração
(ASSALIN; GONTIJO; BOER, 2019; ZHENG et al., 2017). Além disso, um estudo
publicado no Journal of Hepatology mostra que a dieta rica em gordura fornecida
multigeracional aumenta a incidência de carcinoma hepatocelular por indução via a
regulação do eixo miR-27a-3p-Acsl1/Aldh2 (SUN et al., 2020).
27
Referências Bibliográficas
As referências da revisão bibliográfica estão em conjunto com as do capítulo 2.
28
Capítulo 2: MiRNAome integrative analysis reveals molecular
mechanisms associated with development of PCa in the offspring
subjected to maternal low protein diet.
Constantino F.B.1, Protela L.F.1, Camargo A.C.L.1, Colombelli K.T1, Santos S.A1, Fioretto M.N1,
Freire P.P.4, Minatel B.C.3, Barros-Filho M.C.2,3, Kislinger T.5, Moreno C.S.6. Lam W.L.2,
Carvalho R.F.1, Justulin L.A1*
1. Department of Morphology, Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, SP, Brazil
2. Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada
3. International Research Center, A.C. Camargo Cancer Center, Sao Paulo, SP, Brazil
4. Department of Immunology - University of São Paulo (USP), São Paulo, SP, Brazil
5. Medical Biophisics, University of Toronto, Toronto, ON, Canada
6. Departments of Pathology & Laboratory Medicine, and Biomedical Informatics, Emory University School of
Medicine, Atlanta, GA, United State
*Corresponding author:
Prof. Dr. Luis A Justulin
Sao Paulo State University (UNESP), Institute of Biosciences of Botucatu, SP, Brazil.
Zip Code: 18618-689
Phone number: +551438800481
email: l.justulin@unesp.br
mailto:l.justulin@unesp.br
29
Abstract
In the last decades, there has been an increase in the incidence of cancer in the
population. Studies show that cancer can originate through insults suffered by individuals
during intrauterine life, a condition known as Fetal Programming. (PF). The perinatal
period is characterized by the ability of the embryo / fetus to adapt to environmental
changes, altering gene expression by post-transcriptional mechanisms. Recently, we
demonstrated that maternal protein restriction promotes prostate carcinogenesis in
elderly rats; However, information about the molecular mechanism involved in this
process is lacking. Thus, we aimed at identifying possible deregulated microRNAs in
young programmed rats and locate their possible targets associated with prostate
carcinogenesis. For this, male Sprague Dawley rats born to mothers fed a standard diet
(17% protein) - a control group (CTR) or a low protein diet (6% protein) - a gestational
and lactational low protein diet (GLLP), during pregnancy and lactation were sacrificed
on the postnatal day 21. We observed a delay in the development of the ventral prostate
and increased levels of testosterone and estrogen expression in GLLP rats. In addition,
20 miRNAs were identified as differentially expressed, 6 downregulated and 14
upregulated. The enrichment results for downregulated miRNAs are related to cancer and
angiogenesis pathways, while upregulated miRNAs are enriching endoplasmic reticulum
and carcinoma pathways. The reanalysis of miRNA sequencing from TCGA revealed 7
in common with the GLLP group. One of them is miR-33 which, in addition to being down-
regulated in the prostate, is also unregulated in the testis, adrenal gland and liver. Their
overexpression in transfected cells caused a decrease in cell viability and your target,
CYP1B1, which is an important enzyme in estrogen metabolism, leading to
carcinogenesis mediated by changes in hormone levels. We concluded that miR-33 is an
important target to explain the changes caused by maternal LPD and can also be
considered the biomarker because it is unregulated in several organs.
30
1.0 Introduction
Inadequate diet is one of the main causes of comorbidities in the world, being
related to diseases such as cancer, diabetes and neonatal deaths (AFSHIN et al., 2019;
BLACK et al., 2013; CAULFIELD et al., 2004; PELLETIER et al., 1995). Studies show
that maternal malnutrition in early life may be related to an increased likelihood of chronic
diseases emergence in adulthood, showing that the origin of these diseases may be due
to aggressions suffered during the embryo/fetal period. This is one of the themes studied
by the international society named Developmental Origins of Health and Disease
(DOHaD) (BARKER, 2007; MERICQ et al., 2017; PINHO et al., 2014; SANTOS et al.,
2019; SCHULZ, 2010). Maternal exposure to low protein diet (LPD) during pregnancy
and lactation has been widely performed in laboratory models, and it is an example of a
metabolic programming that follows during the critical periods of development
(COLOMBELLI et al., 2017; OZANNE; HALES, 2004; PINHO et al., 2014; SENE et al.,
2013; VEGA et al., 2016). Studies show that offspring whose dams received LPD have
lower birth weight, followed by accelerated growth (catch-up growth), insulin resistance
and type 2 diabetes in adulthood and decreasing life expectancy (ALEJANDRO et al.,
2020; EMBLETON et al., 2016; MCMILLEN; ADAM; MÜHLHÄUSLER, 2005; PETRY et
al., 2001).
In addition, studies have aroused interest in the maternal LPD on the prostate
(PINHO et al., 2014; PORTELA et al., 2021; RAMOS et al., 2010; SANTOS et al., 2020).
Prostate is an exocrine accessory gland to the genital system whose development and
homeostasis are under androgenic control (BIANCARDI et al., 2017; CUNHA et al.,
1985). It is an important gland to the fertility (VERZE; CAI; LORENZETTI, 2016), and has
31
aroused, in recent years, medical-scientific interest, as it has a high incidence of benign
prostatic hyperplasia (BPH) and prostate cancer (PCa), which is the third cancer that most
kills the men in the world (DASGUPTA; SRINIDHI; VISHWANATHA, 2012; “Global
Cancer Observatory”). In a previous study, Santos et al. related maternal LPD to the onset
of prostate cancer (SANTOS et al., 2019). However, little is known about the epigenetic
mechanisms involved in these changes, and studies show that epigenetic factors are the
main modulators of gene expression involved in fetal programming-related risks of
diseases at adulthood (JOUBERT et al., 2016).
Environmental changes can persistently alter epigenetic markers and trigger
phenotypic responses that permanently affect the structure and functioning of the organs
(SINCLAIR et al., 2007; WATERLAND; JIRTLE, 2003). The main mechanisms of
epigenetic regulation include DNA methylation, by DNA methyltransferase enzymes
(DNMT), post-transcriptional modification of histones by histone acetylase (HAC) or
deacetylase (HDAC), in addition to the participation of non-coding RNAs. It is also
included miRNA, which have been also been described as an epigenetic mechanism for
the regulation of gene expression (ALLIS; JENUWEIN, 2016; HEERWAGEN et al., 2010).
MiRNAs are small, single-stranded, evolutionarily conserved molecules (~ 17-25
nucleotides) which suppress the expression of genes that encode proteins, aiming at
translational repression, mRNA degradation or both (SHYU; WILKINSON; VAN HOOF,
2008). Maternal LPD during gestation and lactation deregulated six miRNAs from
offspring mice on postnatal day (PND) 21. Inflammatory pathways (including MAPK, TGF-
beta and Toll-like receptor) have been associated with the six differentially expressed
miRNAs, as well as increased levels of IL-6 and TNF-α in the liver (ZHENG et al., 2017).
32
Another study showed that maternal LPD leads to the dysregulation of two important
miRNAs for the control of PPAR-γ and C/EBP-β expression, transcription factors involved
in the differentiation of adipocytes and fat deposition, affecting lipid metabolism in the
offspring in weaning age (PAN et al., 2013). Thus, maternal LPD have been linked to
miRNA dysregulation, so our objective was to assess the profile of unregulated miRNAs
after maternal LPD and relate them to PCa.
2.0 Material and Methods
2.1 Animals
Male and female Sprague Dawley rats were purchased at the State University of
Campinas (Campinas, SP, Brazil) and kept at the Department of Structural and Functional
Biology at the São Paulo State University (UNESP), Brazil. The animals were maintained
under controlled temperature (22-25°C), photoperiod (12h), and relative humidity (55%)
and received water and feed ad libitum. The animal design was performed according to
SANTOS et al. (2019). Briefly, when 3 months old, weighing about 250-300g, the animals
were placed to mate in a harem model (3 female rats for 1 male rat per box). The
pregnancy confirmation was detected through vaginal washing.The pregnant rats were
distributed into two groups: 1: Control (CTR) group, which received a standard diet (17%
protein) during gestation and lactation; 2: Gestational and lactational low protein diet
(GLLP) group, which received hypoprotein diet (6% protein) during gestation and lactation
(Supplementary Figure 1). At birth, litters were adjusted to eight pups (4 males and 4
females). Male rat pups were weighed and euthanized in postnatal day (PND) 21 through
anesthesia (ketamine and xilazin) followed by decapitation. The blood was collected for
hormonal analysis and the ventral prostate lobe (VP) was collected, fixed for
33
morphological and stereological analysis, and frozen in liquid nitrogen for the extraction
of total RNA to perform the techniques of miRNAs sequencing (microRNAome) and RT-
qPCR. Testicle, adrenal gland, skin, and liver were collected to RT-qPCR.
The experimental procedures are according to the Ethical Principles on Animal
Experimentation adopted by the Brazilian College of Animal Experimentation (COBEA)
and were approved by the Ethics Committee on Animal Experimentation of the Institute
of Biosciences of Botucatu (CEEA-949).
2.2 Morphological Analyses
The ventral prostates (VP) of six animals per litter/group from PND 21 were
removed, and immediately fixed in the methacarn solution during approximately 4 hours
(Puchtler et al 1970). Then, the samples were dehydrated by ethanol followed by
diaphanization in xylene, and later the sample were embedded in Paraplast® Plus (Sigma-
Aldrich Chemicals, St Louis, MO, USA). Consecutive 5 μm serial sections were obtained
and the slides were stained with hematoxylin-eosin for morphological and stereological
analysis. Stereological analysis was performed to analyze the relative proportions of the
VP components (epithelium, lumen, and stroma). Results were expressed as a
percentage of each component and a proportion of the total area analyzed (WEIBEL;
KISTLER; SCHERLE, 1966).
2.3 Hormonal Analysis
The blood sample of 12 animals per litter/group from the PND 21 were collected,
centrifuged and serum was stored until use. Analysis of hormone levels was performed
by the colorimetric Elisa method following the manufacturers’ protocol. The measured
hormones were: Estrogen (17β-estradiol, Monobind®, 4925-300 CA, USA Sensitivity: 6.5
34
pg/mL) and Testosterone (17β-hydroxy-4-androsten-3-one, Monobind®, 3725-300A,
USA. Sensitivity: 0.038 ng/mL).
2.4 Total RNA extraction and miRNA sequencing
Total RNA was extracted from prostate by Invitrogen™ Trizol® Reagent according
to manufacturer’s protocols (Thermo Fisher Scientific, MA, USA). The RNA samples were
quantified by spectrophotometry using the Thermo Scientific™ NanoDrop (Thermo Fisher
Scientific, MA, USA) and treated with Invitrogen™ DNase I (Thermo Fisher Scientific, MA,
USA) to remove contamination with genomic DNA. The quality of the RNA was confirmed
by Bioanalyzer 2100 Eukaryote Total RNA Pico (Agilent Tech, CA, USA) through the RNA
integrity number (RIN), which must be greater than 8.
The libraries were prepared by TruSeq® Small RNA Library Prep Kit (Illumina, CA,
USA). Small non-coding RNA sequencing were performed on the Illumina HiSeq2500 at
Macrogen inc. After sequencing, FASTQ files were pre-processed by adapter trimming
and quality filtering, based on the Phred quality score (≥20). Sequence reads were
aligned to the current version of the Rattus Novegicus genome (Rnor_6.0) using the
Spliced Transcripts Alignment to a Reference (STAR) aligner and annotated miRNA
species quantified based on genomic loci. All these steps were performed at OASIS
Platform (RAHMAN et al., 2018). Differential expression and exploratory analysis were
performed using the DESeq package (Log2FC |0.4|; FDR< 0.05)
(https://yanli.shinyapps.io/DEApp/).
2.5 Integrative analysis
The integrative analysis was carried out using the results of the transcriptome and
proteome from another study of our group (data not published). These results were
https://yanli.shinyapps.io/DEApp/
35
obtained from the same animal model mentioned in this study. For the results of the
transcriptome, mRNAs were considered differently expressed with p-value<0.05 and log2
Fold Change |0.66|. For proteome results, differential expressed proteins were
considered with p-value<0.05 and log2 Fold Change |1|.
To perform the integrative analysis, we first find the target prediction of unregulated
miRNAs using miRWalk 3.0 (http://mirwalk.umm.uni-heidelberg.de/) (DWEEP; GRETZ,
2015). Then, the correlation of miRNAs/mRNAs and miRNAs/proteins were observed
considering values of inverted Fold Change (down/up or up/down).
2.6 Enrichment analysis
The enrichment analysis was done using the results of the Integrative analysis and
was separately performed separately for targets upregulated and downregulated. For this
we use the platform “KEGG Orthology Based Annotation System” (KOBAS)
(http://kobas.cbi.pku.edu.cn/kobas3/?t=1) (XIE et al., 2011) was used. This platform
generates an enrichment from several databases such as Gene Ontology, Panther,
KEGG and Reactome. The pathways were considered enriched with p-adjusted <0.05.
2.7 Quantitative polymerase chain reaction (RT-qPCR)
RT-qPCR for miRNAs were performed according to the relevant literature
(VARKONYI-GASIC et al., 2007).
The cDNA was synthesized using the Applied Biosystems™ High-Capacity cDNA
Reverse Transcription Kit according to the manufacturer. For miRNAs, the stem-loop RT
primer, designed according to (CHEN, 2005), was hybridized with the selected miRNA
molecule giving rise to the reverse primer (Table 2). This reverse primer was used to
http://mirwalk.umm.uni-heidelberg.de/
http://kobas.cbi.pku.edu.cn/kobas3/?t=1
36
perform the miRNA cDNA instead of the Rondon primer used for mRNA cDNA. The cDNA
reaction product was amplified using specific primers (Table 2) and Applied Biosystems™
SYBR™ Green PCR Master Mix system (Thermo Fisher Scientific, MA, USA). For
miRNAs reaction was used the primer Forward and the primer universal described in table
2. The reactions were performed in duplicates for each target gene in the Applied
Biosystems™ QuantStudio™ 12K Flex Real-Time PCR System (Thermo Fisher
Scientific, MA, USA) in 96-well plates according to the manufacturer's instructions. The
relative quantification of each gene was performed using the 2-∆∆CT method (LIVAK;
SCHMITTGEN, 2001). The values obtained for all samples were normalized by the
reference miRNA (U6) and mRNA (actin). The values were calculated using the
expression ratio of the GLLP/CTR groups. Student's “t” test was applied and considered
statistically significant when p <0.05. The sequences of the primers pair used are
described in table 2.
Table 2. Sequences of primers.
2.8 TCGA data: a translational analysis
Raw prostate miRNA sequencing data from “The Cancer Genome Atlas” (TCGA)
repository (https://portal.gdc.cancer.gov/repository), which contains 498 samples from
patients with prostate cancer and 52 samples from a solid tissue (as a control group) were
downloaded. Oasis platform (https://oasis.dzne.de/) was used to reanalyze this data with
the same protocol used for rat data, but aligned with the most current construction of the
Foward Reverse
miR-33-5p CGGCGGGTGCATTGTAGTTGCATTGCA GTCGTATCCAGTGCAGGGTCCGAGGTATTCGCACTGGATACGACTGCAAT
U6 GCAAATTCGTGAAGCGTTCC GTCGTATCCAGTGCAGGGTCCGAGGTATTCGCACTGGATACGACAAAAATAT
Universal GTGCAGGGTCCGAGGT
CYP1B1 (rat) GGGCTGGATTTGGAGGATGT TCCTGGCTGGCTCCAAAG
SEMA6C (rat) TCTGCAGTCTGCGCCTTCT CCTTGAACTTGCCCTCAAAGC
CYP1B1 (Human) TCCTCCTCTTCACCAGGTATCC CTGGTCACCCATACAAGGCA
SEMA6C (Human) CTCCGAGAGCCACACTTTGT CGAGCATCCTCCACAGAGAC
https://portal.gdc.cancer.gov/repository
https://oasis.dzne.de/
37
human genome (hg38) (RAHMAN et al., 2018). miRNAs were considered differentially
expressed with FDR>0.05 and log2 fold change |0.4|. The differentially expressed
miRNAs of patients with prostate cancer were compared with unregulated miRNAs of the
GLLP group.
Also, mRNAs results from GEPIA were also used to compare with target prediction
of the miR-33a-5p. GEPIA is a Web Site that analyzed RNA sequencing expression data
of 9,736 tumors (TCGA) and 8,587 normal samples (GTEx) using a standard processing
pipeline (Cite GEPIA). mRNAs were considered differentially expressed with FDR>0.05
and log2 fold change |0.4|.
2.9 Cellular Culture
Non-cancerous prostate cells, PNT2 cell line (Rio de Janeiro Cell Bank - BCRJ,
Rio de Janeiro, Brazil), were maintained in Gibco™ RPMI 1640 Medium (Thermo Fisher
Scientific, MA, USA). The cells were expanded in 25 cm2 and 75 cm2 polystyrene plates
and kept in an oven with 5% CO2 in a humid atmosphere at 37ºC. When the cells reached
80% confluence, they were subjected to 0.25% Gibco™ Trypsin-EDTA (0.5%), no phenol
red (Thermo Fisher Scientific, MA, USA) and transferred to 12-well plates to compose the
study groups. Each experimental group (explained in the next topic) was performed in
triplicate and three biological repetitions.
2.9.1 Cellular Transfection
To form the different study groups, hsa-miR-33a-5p mimics were transfected into
the cell. For this, two complexes were formed to be used in the final transfection solution.
First, Invitrogen™ Lipofectamine™ RNAiMAX Transfection Reagent (Thermo Fisher
Scientific, MA, USA) was diluted in Gibco™ Opti-MEM Reduced Serum Medium (Thermo
38
Fisher Scientific, MA, USA) to form the first complex. Then, the oligonucleotides were
diluted in Opti-MEM® to form the second complex. The Lipofectamine+Opti-MEM
complex was mixed with the oligos+Opti-MEM complex and incubated for 5 minutes at
room temperature. After this period, 150 μl of the final transfection solution was added to
each well containing PNT2 cells (80% confluence) and normal culture medium. The cells
were incubated for a period of 15 hours and the medium with the treatment were
exchanged by the specific medium. After 24 hours, the cells were collected and
processed for extraction of total RNA using Invitrogen™ Trizol® Reagent according to
manufacturer’s protocols (Thermo Fisher Scientific, MA, USA) or added Invitrogen™ MTT
(3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) (Thermo Fisher Scientific,
MA, USA) solution to analyze cell viability after treatment.
2.9.2 Cell viability assay
PNT2 cells were seed in a 12-weel plates and treated with mimic as previously
described. After 24, 48 or 72 hours of the treatment, the cell medium was removed and
200 µl of a 10% MTT solution (Invitrogen™ MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-
Diphenyltetrazolium Bromide) (Thermo Fisher Scientific, MA, USA)) was added. 4 hours
later, the medium containing MTT solution was removed and 300 μl DMSO was added
directly to each well. We replaced the solution in a 96-well plate (each well in the 12-well
plate becoming 3 in the 96-well plate). The optical density of each well was measured by
spectrophotometer at the wavelength of 550 nm. The experiments were performed in
triplicate.
2.10. Statistical Analysis
39
For global analyzes, specific statistical packages were used, as previously
described. For the other parameters, the Shapiro-Wilk normality test was performed. For
the data that passed the test, the comparison between the experimental groups was
perform using the Student's T test. For data that did not pass the normality test, the Mann-
Whitney test was performed. A statistically significant difference was considered when p
<0.05.
2.11. Making the images
The PCA graph was generated using the Clustvis tool (https://biit.cs.ut.ee/clustvis/)
(METSALU; VILO, 2015) and the volcano graph on the VolcaNoseR website
(https://huygens.science.uva.nl/VolcaNoseR/). Heatmap graphic was generated on the
Morpheus platform (https://software.broadinstitute.org/morpheus/) and Sankey diagram
using SankeyMATIC Web site (http://sankeymatic.com/).
3.0 Results
3.1 Animals of the GLLP group have lower body and prostate weight in
addition to high levels of estrogen and testosterone.
The animals subjected to maternal low protein diet (LPD)during gestation and
lactation had a lower birth weight that remained until PND 21 (Fig. 1A and Table 1). In
addition, the prostate weights, normalized by the weight of the animal (relative) or not,
were also lower in the GLLP group (Table 1).
The prostatic tissue morphometry of the CTR experimental animals present dilated
acini, with ample light and full of secretion and with a cylindrical secretory epithelium
associated with fibromuscular stroma (Fig. 1B). The GLLP animals, the animals in the
GLLP group had smaller acini, with reduced light and more evident stroma when
https://huygens.science.uva.nl/VolcaNoseR/
https://software.broadinstitute.org/morpheus/
http://sankeymatic.com/
40
compared with the CTR group (Fig. 1B). Stereological analyses were corroborated by
histological data, where we observed a decrease in light and an increase in stroma in the
GLLP group in relation to CTR (Table 1). The estrogen and testosterone levels were
increased in the GLLP group (Fig. 1C).
41
Figure 1. The GLLP group has lower weight, late prostate development and a higher level of testosterone and
estrogen. A. Representative images of male rat pups from experimental groups at different ages. We can observe the
difference between the groups: GLLP group is lower in both ages. B. Histological sections of the ventral prostate lobes
(VP) stained with hematoxylin-eosin (HE) showing the delayed prostate development marked by smaller acinus and
more evident stroma in GLLP group. C. Bar graph of blood hormone measurement (Estrogen and Testosterone)
showing the high levels in GLLP group of both hormones. CTR: Control group; GLLP: Gestation and lactation low
protein diet; PND: Postnatal day VP: Ventral prostate. ep: epithelium; st: stroma; L: lumen. * means statistical difference.
Scale bar: 200 μm.
Table 1. Rat and prostate weight and stereological results.
CTR: Control, GLLP: Gestation and lactation low protein diet, PND: Postnatal day, VP: Ventral prostate,
g: grams. * means statistical difference
3.2 Performance of miRNAs differentially expressed in the GLLP group:
Target prediction, integration analysis (transcriptome and proteome) and pathways
enrichment analysis.
The 605 readings mapped for each sample were found after analysis on the
Oasis platform and the raw data were sent to the database (unpublished data). We
identified a differential expression profile between CTR and GLLP group by principal
component analysis (PCA) (Figure 2A). Six miRNAs (rno-miR-33-5p, rno-miR-871-3p,
rno-miR-3553, rno-miR-144-5p, rno-miR-99a-5p and rno-miR-7a-5p) have been identified
that are at least 1.3 times less expressed in the GLLP group compared to CTR and
fourteen miRNAs (rno-miR-708-5p, rno-miR-487b-3p, rno-miR-337-3p, rno-miR-411-3p,
rno-miR-410-3p, rno-miR-496-3p, rno-miR-323-3p, rno-miR-299a-5p, rno-miR-412-3p,
CTR GLLP
PND1 Rat weight (g) 6.62 ± 0.4 6.02 ± 0.5 *
PND21 Rat weight (g) 39.25 ± 6.2 20.02 ± 2.9 *
VP weight (g) 0.03 ± 0.006 0.01 ± 0.003 *
VP relative weight (g) 0.0009 ± 0.0001 0.0007 ± 0.0001 *
Epithelium(%) 35.71 ± 5.8 48.05 ± 6.1 *
Lumen (%) 45.47 ± 9.8 30.50 ± 4.9 *
Stroma (%) 19.79± 5.4 29.63 ± 4.9 *
Glandular fraction 82.04 ± 5.2 67.58 ± 14.3 *
42
rno-miR-493-5p, rno-miR-483-5p, rno-miR-6331, rno-miR-184, rno-miR-483-3p) are
expressed at least 1.3 times more in the GLLP group as compared to the CTR (Figure
2B).
Target prediction for the 20 miRNAs resulted in 8172 potential targets
(Supplementary Table 2). These predicted targets were compared with transcriptome and
proteomic data (unpublished), which identified 708 differentially expressed mRNAs (525
regulated up and 183 down regulated) and 289 deregulated proteins (163 regulated up
and 126 regulated down) in the GLLP group when compared with the CTR group
(Supplementary Table 3). Thus, after integrative analysis of these data considering
inverted fold changes levels, 80 targets with increased expression were identified (52
mRNAs, 28 proteins and 0 common) (Figure 2C) and 119 targets with decreased
expression (64 mRNA, 53 proteins and 2 in common) (Figure 2D), totaling 199 possible
targets of miRNAs (Supplementary Table 4).
The enrichment analysis for 80 upregulated targets enriched terms related
to: Proteoglycans in cancer, positive regulation of angiogenesis, cellular response to
tumor necrosis factor, Hepatocellular carcinoma, regulation of vascular endothelial
growth factor production, response to estradiol, Pathways in cancer, Wnt signaling
pathway (Figure 2.E and Supplementary Table 5). For the 119 down regulated targets,
the enriched pathways are related to: Endoplasmic reticulum, Hepatocellular carcinoma,
positive regulation of ERAD pathway (Figure 2.A and Supplementary Table 6).
43
Figure 2. MiRNAs differentially expressed in the GLLP group have predicted targets related to interesting
enriched pathways. A. Principal component analysis (PCA) show similarities between samples within each group. Red
circle delimits the set of samples from the CTR group, and blue circle delimits the set of samples from the GLLP group.
B. Heatmap showing the expression in log2 of Fold change (red up regulated, blue down regulated) and FDR (larger
44
circle size represents larger FDR value) of the differentially expressed miRNAs. C. Venn diagram showing the
integration of predicted targets of downregulated miRNAs with upregulated mRNAs and proteins. D Venn diagram
showing the integration of predicted targets of upregulated miRNAs with downregulated mRNAs and proteins. E. Bar
graphs showing the ontological pathways and terms enriched of the miRNAs integrated predicted targets. Red bars
refer to upregulated miRNAs integrated predicted targets; blue bars refer to downregulated miRNAs integrated
predicted targets. The numbers below de bars represent the adjusted p-value shown in –log10. CTR: Control; GLLP:
Gestational and lactational low protein intake.
3.5 Translational Analysis: Results of prostate cancer (TCGA) and
correlation with rat data.
Using TCGA small-RNA sequencing, the expression of 1010 miRNAs was
detected. The Differential expression profile was identified between the solid tissue group
(CTR) and the Cancer group by principal component analysis (PCA) (Figure 3.A). The
volcano graph (Fig. 3.B) identified 243 miRNAs that are downregulated in the Cancer
group, and 248 miRNAs upregulated (Supplementary Table 7). Values of FDR> 0.05 and
Log2 Fold Change of ± 0.4 were considered.
The correlation between the Rat and Human differentially expressed miRNAs
resulted in 7 miRNAs in common (Figure 3.C and Supplementary Table 8). From this, five
are upregulated in GLLP group but downregulated in cancer samples. The miR-708-5,
are upregulated in both groups and the miR-33-5p, are downregulated in both groups.
Considering everything that has already been mentioned, from fold change values,
enriched pathways and relationship with prostate cancer, mir-33-5p was evident in all
criteria, proving to be a good miRNA to be studied.
45
Figure 3. GLLP group presents some deregulated miRNAs in common with prostate cancer patients. A.
Principal component analysis (PCA) shows similarities between samples within each group. Blue circle delimits the set
of samples from the CTR group (n=52), and red circle delimits the set of samples from the cancer group (n=498). B.
Volcano graph with the differential expression between the two experimental conditions. The vertical axis corresponds
to log2 Fold Change <0.4> and the horizontal axis represents values of FDR <0.05 expressed in -log10. C. Heatmap
showing the expression in log2 of Fold change (red upregulated, blue downregulated) and FDR (larger circle size
represents larger FDR value) of the differentially expressed miRNAs in common between prostate cancer patients and
GLLP group.
3.6 An exploratory analysis of miR-33a-5p
The first analysis performed with miR-33 was to prove its downregulation in the
prostate of animals in the GLLP group using the RT-qPCR method (Fig. 4). In addition,
the expression of this miRNA is also downregulated in the testis and liver. Furthermore,
the expression of miR-33 was increased in the adrenal gland, on the GLLP group, and
the expression levels of miR-33 were not different in the skin (Fig. 4).
46
Figure 4. Expression of mir-33-5p using the RT-qPCR technique in different organs showing the lower
expression in prostate, testicle and liver and a higher level in adrenal gland in GLLP group when compared to CTR.
Prostate statistics was Student T test (bar graph) and the other organs Mann-Whitney test (box plot graph) CTR: Control
group; GLLP: Gestation and lactation low protein diet. * means statistical difference.
The second analysis was to transfect the PNT2 cell line with miR-33,
thereby increasing its expression. The technique was successfully performed, where the
expression levels of cells treated with miR-33 MIMIC showed high expression levels while
cells that were only treated with lipofectamine did not have their levels increased (Fig.
5A). This overexpression of miR-33 persisted significantly until at least 72 hours after the
end of treatment, although expression levels have decreased (Fig. 5B).
To see the effect of mir-33a-5p overexpression on the culture cell line, we
performed the MTT test to analyze cell viability. The result for this assay shows that the
overexpression of mir-33a-5p decrease the cell viability levels (Fig. 5C).
47
Figure 5. miR-33a-5p overexpression causes low levels of cell viability A. miR-33a-5p expression in PNT2
cell after treatment with Mimic (higher levels) or Lipofectamine alone (normal levels) represented by a Box plot. B. Line
graph showing miR-33-5p expression levels after 24, 48 and 72 hours of treatment with Mimic. Expression levels in 24
hours are higher, but the difference remains significant until 72 hours, which was the last hour analyzed. C. Cell viability
levels performed by MTT 24, 48 and 72 hours after the end of the treatment with mimic. The line graph shows the low
levels of cell viability when miR-33a-5p is overexpressed. CTR: Control group; GLLP: Gestation and lactation low
protein diet. * means statistical difference.
When we look at the enriched pathways of the downregulated miRNAs, we see
that the targets of miR-33 are present in all of them, showing the importance of miR-33
for the regulation of the organism (Fig. 6A). In addition, we used RNA sequencing data
results analyzed by Gepia from 9,736 tumors patientes (TCGA) and 8,587 normal
48
samples (GTEx) to compare with the miR-33 predicted targets and we observed 6 targets
that is deregulated in both (Fig. 6B). From this results we choose two miR-33 targets
predicted to validated, the SEMA6C and CYP1B.
The expression of both targets presented upregulated in GLLP animals (Fig. 6C)
but there was no difference in the transfected cell line (Fig 6D).
Figure 6. The predicted mir-33-5p targets are involved in all selected pathways and with prostate cancer. A.
Sankey diagram showing the pathways enriched by predicted integrated targets of the upregulated miRNAs and the
targets that are enriching the pathways. Red circle highlights the miR-33-5p targets. B. Venn diagram showing shared
between deregulated mRNAs in prostate cancer with the predicted and integrated miR-33 targets. C. Expression levels
of two predicted mir-33 targets (SEMAC and CYp1B1) in the prostate of rats in the CTR and GLLP group. The results
49
show that the downregulation of miR-33 leads to increased expression of the targets. D. Expression levels of two
predicted mir-33 targets (SEMAC and CYp1B1) in PNT2 cells transfected with mimic miR-33a-5p.
4.0 Discussion
The term malnutrition is associated with the inadequate or insufficient intake of any
food component, such as proteins. The minimum percentage of protein recommended by
the American Institute of Nutrition for rat diets is 12% (NUTRITION, 1995). In our study,
only 6% of the protein was made available to rats, that is, half of the recommended.
Several authors have shown that feed intake with hypoproteins is associated with low
birth weight and reduced growth of different organs in rodent models. (DE BRITO ALVES
et al., 2016; FALCÃO-TEBAS et al., 2012; LEANDRO et al., 2012; LIMA et al., 2015;
OZANNE; HALES, 2004). In our animals it was not different, the GLLP animals had a
lower body weight at birth, in addition to a significant decrease weight in the prostate,
which may be related to the delay in the development of this organ, which had smaller
acini, with less light and increased stroma. These data corroborate the results of Santos
et al. (2019) demonstrated a reduction in the prostate luminal fraction , as well as a
decreased glandular secretion, produced by the quantification of the prostatein protein in
LPD animals in PND 21. In addition, Ramos et al. (RAMOS et al., 2010) identified smaller
amount and reduced size of acini in the dorsolateral prostate of rats exposed to
intrauterine protein restriction and Pinho et al. (2014) also observed a delay in prostate
development in the offspring of animals following the same protocol but with PND 1.
In addition to the morphological alterations, we found important hormonal changes,
such as an increase in serum testosterone and estrogen in this PND 21 animal model.
Studies show that prostate exposure to high testosterone levels is a potential carcinogen
in the prostate, where 30% of animals with low doses but with chronic testosterone have
50
prostate cancer. However, estrogen has a synergistic effect with testosterone, 100% of
animals exposed to testosterone doses associated with estrogen developed prostate
cancer. (BOSLAND, 2005). Zambrano el al. (ZAMBRANO et al., 2014) observed that
mothers who have low protein intake have high levels of estrogen in the gestational
period. Thus, this may be one of the mechanisms that assist in the appearance of prostate
cancer in aging animals, since studies show that the development of the prostate is
sensitive to hormonal changes and exposure in the early stages of life can play a
significant role in the appearance of precancerous lesions and carcinogenesis in
adulthood through epigenetic changes (PRINS et al., 2008).
Epigenetics are inherited changes in gene expression without undergoing changes
in DNA sequences. Interestingly, miRNAs are also considered an important epigenetic
component, as they are targets for methylation of their DNA and for regulating epigenetic
modifiers such as DNMTs and deacetylated histones (SALIMINEJAD et al., 2019). Some
studies have already shown that maternal LPD causes the dysregulation of miRNAs that
can lead to metabolic changes, chronic inflammation, increased blood pressure and
morphological changes in the heart (ASSALIN; GONTIJO; BOER, 2019; ZHENG et al.,
2017). In our study, maternal LPD caused alteration of 20 miRNAs and after integrating
predicted targets with protein and mRNA data, we observed that miRNAs are enriching
many cancer-related pathways. When we compared the 20 unregulated miRNAs with the
491 unregulated miRNAs of prostate cancer patients (TCGA data) we find 7 miRNAs in
common. Our data suggest that miRNAs deregulated by fetal programming due to LPD
may be influencing the microenvironment in order to predispose to the onset of cancer.
51
Among miRNAs, miR-33 has been widely studied both for its tumor suppressive
effect, considering that its positive regulation decreases proliferation inhibiting tumor
growth, and reducing the chance of metastasis by affecting cell migration, which can be
a powerful strategy for the treatment of cancer (CIRERA-SALINAS et al., 2012;
FRIEDMAN et al., 2012; KUO et al., 2013; RICE et al., 2013; THOMAS et al., 2012; ZHOU
et al., 2015), and for its role in regulating cholesterol / lipid metabolism, being an important
therapeutic target for atherosclerosis (HORIE et al., 2010; MARQUART et al., 2010;
NAJAFI-SHOUSHTARI et al., 2010; RAYNER et al., 2010, 2011a, 2011b; ROTLLAN
NOEMI et al., 2013; ROTTIERS et al., 2013). In addition, studies have shown that miR-
33 inhibition leads to the development of obesity, insulin resistance and increased food
intake, in organs such as liver, white adipose tissue and skeletal muscle, suggesting that
the metabolic regulation by miR-33 is more complex than was known (NÄÄR, 2018;
PRICE et al., 2018). The low-protein maternal diet offered at the end of pregnancy affects
the fraction of offspring pancreatic β cells at birth, increasing their susceptibility to
metabolic disorders and type 2 diabetes in adulthood. In addition to increasing glucose
intolerance and reducing insulin sensitivity in aging male offspring (ALEJANDRO et al.,
2020; BERENDS et al., 2018). Putting all information about miR-33 together, we can
suggest that it is an important miRNA for fetal programming. In addition, miR-33 is
deregulated not only in the prostate, but also in the testicle, adrenal and liver shown that
it can be a biological marker for programming low protein intake.
Among the targets of miR-33, we chose 2 to perform the validation, SEMA6C and
CYP1B1. Semaphorins are a family of proteins that, in addition to being important for the
immune response because they have receptors in most defense cells, also play an
52
important role in the tumor microenvironment (FRANZOLIN; TAMAGNONE, 2019). For
example, SEMA6D has been described as being associated with tumor progression and
angiogenesis in gastric cancer (LU et al., 2016; ZHAO, 2006). SEMA7A expression is
positively regulated in breast cancers and is associated with shorter survival (BLACK et
al., 2016). In certain tumors, SEMA3E has been associated with progression due to the
promotion of cell invasion, metastatic spread and tumor angiogenesis. (CASAZZA et al.,
2010, 2012; LUCHINO et al., 2013; TAMAGNONE; MAZZONE, 2011).
Cytochrome P450 1B1 (CYP1B1) is an important enzyme in estrogen metabolism
(DAWLING et al., 2004; HAYES et al., 1996; LI; ZHU; GONZALEZ, 2017). Studies have
shown that high levels of CYP1B1 can lead to carcinogenesis mediated by changes in
hormone levels and the transformation of estradiol into semiquinones and quinones,
which can form DNA adducts resulting in oncogenic mutations (GAJJAR; MARTIN-
HIRSCH; MARTIN, 2012; HAYES et al., 1996; SPINK et al., 1997). In addition, quinones
/ semiquinones also undergo a redox cycle and generate reactive oxygen species,
resulting in oxidative damage (PARL et al., 2009). Thus, high levels of estrogen,
associated with low levels of miR-33 (suppressor CIP1B1) and high levels of CIP1B1 and
SEMA6C may be combined, leading to a carcinogenic microenvironment that associated
with other factors may be the origin of the cancer found in these animals at age adult.
CYP1B1 is an important fatty acid modulator that suppresses the expression of the
target genes PPARγ and PPARα, receptors for fatty acid metabolism, which play
important roles in energy maintenance homeostasis. Cancer and obesity are closely
related to disruption of fatty acid metabolism. Santos et al. showed that animals
programmed by maternal LPD during pregnancy and lactation have low levels of
53
triglycerides, total protein, albumin, and glucose in the DPN21 (SANTOS et al., 2019).
These results show that in addition to the action of CYP1B1 on hormone levels, it may
also be regulating fatty acid metabolism.
Thus, we conclude that the effect of maternal LPD during pregnancy and lactation
cause changes in miRNAs important for the tumor microenvironment been one of them
the miR-33. We also proved the regulation of this miRNA in two targets, SEMA6C and
CYP1B1 in rat samples. We also observed that miR-33 can be an important biomarker
for fetal programming due to maternal protein restriction, being deregulated in other
organs such as the liver, testis, and adrenal gland.
54
5.0 Reference
AFSHIN, A. et al. Health effects of dietary risks in 195 countries, 1990–2017: a systematic
analysis for the Global Burden of Disease Study 2017. The Lancet, v. 393, n. 10184, p.
1958–1972, maio 2019.
AHMAD, I.; SANSOM, O. J.; LEUNG, H. Y. Advances in mouse models of prostate
cancer. Expert Reviews in Molecular Medicine, v. 10, p. e16, 9 jun. 2008.
ALEJANDRO, E. U. et al. Maternal low-protein diet on the last week of pregnancy
contributes to insulin resistance and β-cell dysfunction in the mouse offspring. American
Journal of Physiology-Regulatory, Integrative and Comparative Physiology, v. 319,
n. 4, p. R485–R496, 1 out. 2020.
ALLIS, C. D.; JENUWEIN, T. The molecular hallmarks of epigenetic control. Nature
Reviews Genetics, v. 17, n. 8, p. 487–500, ago. 2016.
ASSALIN, H. B.; GONTIJO, J. A. R.; BOER, P. A. miRNAs, target genes expression and
morphological analysis on the heart in gestational protein-restricted offspring. PLOS
ONE, v. 14, n. 4, p. e0210454, 29 abr. 2019.
AUMÜLLER, G.; SEITZ, J. Protein secretion and secretory processes in male accessory
sex glands. International Review of Cytology, v. 121, p. 127–231, 1990.
BARKER, D. J. et al. Weight in infancy and death from ischaemic heart disease. Lancet
(London, England), v. 2, n. 8663, p. 577–580, 9 set. 1989.
BARKER, D. J. et al. Fetal and placental size and risk of hypertension in adult life. BMJ :
British Medical Journal, v. 301, n. 6746, p. 259–262, 4 ago. 1990.
BARKER, D. J. et al. Fetal nutrition and cardiovascular disease in adult life. Lancet
(London, England), v. 341, n. 8850, p. 938–941, 10 abr. 1993.
BARKER, D. J. P. Maternal nutrition, fetal nutrition, and disease in later life. Nutrition, v.
13, n. 9, p. 807–813, set. 1997.
BARKER, D. J. P. The origins of the developmental origins theory. Journal of Internal
Medicine, v. 261, n. 5, p. 412–417, maio 2007.
BENATTI, R. O. et al. Maternal high-fat diet consumption modulates hepatic lipid
metabolism and microRNA-122 (miR-122) and microRNA-370 (miR-370) expression in
offspring. British Journal of Nutrition, v. 111, n. 12, p. 2112–2122, jun. 2014.
55
BERENDS, L. M. et al. Programming of central and peripheral insulin resistance by low
birthweight and postnatal catch-up growth in male mice. Diabetologia, v. 61, n. 10, p.
2225–2234, 2018.
BIANCARDI, M. F. et al. Female prostate: historical, developmental, and morphological
perspectives. Cell Biology International, v. 41, n. 11, p. 1174–1183, nov. 2017.
BLACK, M. J. et al. Accelerated age-related decline in renal and vascular function in
female rats following early-life growth restriction. American Journal of Physiology.
Regulatory, Integrative and Comparative Physiology, v. 309, n. 9, p. R1153-1161, 1
nov. 2015.
BLACK, R. E. et al. Maternal and child undernutrition and overweight in low-income and
middle-income countries. The Lancet, v. 382, n. 9890, p. 427–451, ago. 2013.
BLACK, S. A. et al. Semaphorin 7a exerts pleiotropic effects to promote breast tumor
progression. Oncogene, v. 35, n. 39, p. 5170–5178, 29 set. 2016.
BOHNSACK, M. T.; CZAPLINSKI, K.; GORLICH, D. Exportin 5 is a RanGTP-dependent
dsRNA-binding protein that mediates nuclear export of pre-miRNAs. RNA (New York,
N.Y.), v. 10, n. 2, p. 185–191, fev. 2004.
BOMMER, G. T. et al. p53-mediated activation of miRNA34 candidate tumor-suppressor
genes. Current biology: CB, v. 17, n. 15, p. 1298–1307, 7 ago. 2007.
BOSLAND, M. C. The Role of Estrogens in Prostate Carcinogenesis: A Rationale for
Chemoprevention. Reviews in Urology, v. 7, n. Suppl 3, p. S4–S10, 2005.
BURNS, S. P. et al. Gluconeogenesis, glucose handling, and structural changes in livers
of the adult offspring of rats partially deprived of protein during pregnancy and lactation.
The Journal of Clinical Investigation, v. 100, n. 7, p. 1768–1774, 1 out. 1997.
BURTON, G. J.; FOWDEN, A. L.; THORNBURG, K. L. Placental Origins of Chronic
Disease. Physiological Reviews, v. 96, n. 4, p. 1509–1565, 2016.
CAI, X.; HAGEDORN, C. H.; CULLEN, B. R. Human microRNAs are processed from
capped, polyadenylated transcripts that can also function as mRNAs. RNA (New York,
N.Y.), v. 10, n. 12, p. 1957–1966, dez. 2004.
CALIN, G. A. et al. Human microRNA genes are frequently located at fragile sites and
genomic regions involved in cancers. Proceedings of the National Academy of
Sciences of the United States of America, v. 101, n. 9, p. 2999–3004, 2 mar. 2004.
CALZADA, L. et al. Maternal protein restriction during gestation impairs female offspring
pancreas development in the rat. Nutrition Research (New York, N.Y.), v. 36, n. 8, p.
855–862, 2016.
56
CASAZZA, A. et al. Sema3E–Plexin D1 signaling drives human cancer cell invasiveness
and metastatic spreading in mice. Journal of Clinical Investigation, v. 120, n. 8, p.
2684–2698, 2 ago. 2010.
CASAZZA, A. et al. Tumour growth inhibition and anti‐metastatic activity of a mutated
furin‐resistant Semaphorin 3E isoform. EMBO Molecular Medicine, v. 4, n. 3, p. 234–
250, mar. 2012.
CAULFIELD, L. E. et al. Undernutrition as an underlying cause of child deaths associated
with diarrhea, pneumonia, malaria, and measles. The American Journal of Clinical
Nutrition, v. 80, n. 1, p. 193–198, jul. 2004.
CHAKRABORTY, C. et al. The Interplay among miRNAs, Major Cytokines, and Cancer-
Related Inflammation. Molecular Therapy - Nucleic Acids, v. 20, p. 606–620, 5 jun.
2020.
CHEN, C. Real-time quantification of microRNAs by stem-loop RT-PCR. Nucleic Acids
Research, v. 33, n. 20, p. e179–e179, 27 nov. 2005.
CIRERA-SALINAS, D. et al. Mir-33 regulates cell proliferation and cell cycle progression.
Cell Cycle, v. 11, n. 5, p. 922–933, mar. 2012.
COLOMBELLI, K. T. et al. Impairment of microvascular angiogenesis is associated with
delay in prostatic development in rat offspring of maternal protein malnutrition. General
and Comparative Endocrinology, v. 246, p. 258–269, maio 2017.
CUNHA, G. R. et al. Stromal-epithelial interactions in adult organs. Cell Differentiation,
v. 17, n. 3, p. 137–148, set. 1985.
DAHRI, S. et al. Islet function in offspring of mothers on low-protein diet during gestation.
Diabetes, v. 40 Suppl 2, p. 115–120, dez. 1991.
DASGUPTA, S.; SRINIDHI, S.; VISHWANATHA, J. K. Oncogenic activation in prostate
cancer progression and metastasis: Molecular insights and future challenges. Journal of
Carcinogenesis, v. 11, p. 4, 2012.
DAVIS-DUSENBERY, B. N.; HATA, A. Mechanisms of control of microRNA biogenesis.
Journal of Biochemistry, v. 148, n. 4, p. 381–392, out. 2010.
DAWLING, S. et al. In Vitro Model of Mammary Estrogen Metabolism: Structural and
Kinetic Differences between Catechol Estrogens 2- and 4-Hydroxyestradiol. Chemical
Research in Toxicology, v. 17, n. 9, p. 1258–1264, set. 2004.
DE BRITO ALVES, J. L. et al. Maternal protein restriction induced-hypertension is
associated to oxidative disruption at transcriptional and functional levels in the medulla
oblongata. Clinical and Experimental Pharmacology and Physiology, v. 43, n. 12, p.
1177–1184, dez. 2016.
57
DEANS, C.; MAGGERT, K. A. What Do You Mean, “Epigenetic”? Genetics, v. 199, n. 4,
p. 887–896, abr. 2015.
DEARDEN, L.; OZANNE, S. E. The road between early growth and obesity: new twists
and turns. The American Journal of Clinical Nutrition, v. 100, n. 1, p. 6–7, jul. 2014.
DENLI, A. M. et al. Processing of primary microRNAs by the Microprocessor complex.
Nature, v. 432, n. 7014, p. 231–235, 11 nov. 2004.
DERMER, G. B. Basal cell proliferation in benign prostatic hyperplasia. Cancer, v. 41, n.
5, p. 1857–1862, maio 1978.
DWEEP, H.; GRETZ, N. miRWalk2.0: a comprehensive atlas of microRNA-target
interactions. Nature Methods, v. 12, n. 8, p. 697, ago. 2015.
EMBLETON, N. D. et al. Catch-up growth and metabolic outcomes in adolescents born
preterm. Archives of Disease in Childhood, v. 101, n. 11, p. 1026–1031, 2016.
FALCÃO-TEBAS, F. et al. Maternal low-protein diet-induced delayed reflex ontogeny is
attenuated by moderate physical training during gestation in rats. British Journal of
Nutrition, v. 107, n. 3, p. 372–377, 14 fev. 2012.
FERNANDEZ-TWINN, D. S.; CONSTÂNCIA, M.; OZANNE, S. E. Intergenerational
epigenetic inheritance in models of developmental programming of adult disease.
Seminars in Cell & Developmental Biology, v. 43, p. 85–95, jul. 2015.
FITZHARDINGE, P. M.; STEVEN, E. M. The Small-for-Date Infant I. Later Growth
Patterns. Pediatrics, v. 49, n. 5, p. 671–681, 1 maio 1972.
FRANZOLIN, G.; TAMAGNONE, L. Semaphorin Signaling in Cancer-Associated
Inflammation. International Journal of Molecular Sciences, v. 20, n. 2, p. 377, 17 jan.
2019.
FRIEDMAN, E. B. et al. Serum microRNAs as biomarkers for recurrence in melanoma.
Journal of Translational Medicine, v. 10, n. 1, p. 155, 2012.
GAJJAR, K.; MARTIN-HIRSCH, P. L.; MARTIN, F. L. CYP1B1 and hormone-induced
cancer. Cancer Letters, v. 324, n. 1, p. 13–30, nov. 2012.
Global Cancer Observatory. Disponível em: . Acesso em: 26 maio.
2021.
GLUCKMAN, P. D.; HANSON, M. A.; BUKLIJAS, T. A conceptual framework for the
developmental origins of health and disease. Journal of Developmental Origins of
Health and Disease, v. 1, n. 1, p. 6–18, fev. 2010.
GREGORY, R. I. et al. The Microprocessor complex mediates the genesis of microRNAs.
Nature, v. 432, n. 7014, p. 235–240, nov. 2004.
58
HABIB, S. L. et al. Diabetes and risk of renal cell carcinoma. Journal of Cancer, v. 3, p.
42–48, 2012.
HAMMOND, S. M. et al. Argonaute2, a link between genetic and biochemical analyses of
RNAi. Science (New York, N.Y.), v. 293, n. 5532, p. 1146–1150, 10 ago. 2001.
HAN, J. et al. The Drosha-DGCR8 complex in primary microRNA processing. Genes &
Development, v. 18, n. 24, p. 3016–3027, 15 dez. 2004.
HAYES, C. L. et al. 17 beta-estradiol hydroxylation catalyzed by human cytochrome P450
1B1. Proceedings of the National Academy of Sciences, v. 93, n. 18, p. 9776–9781,
3 set. 1996.
HEERWAGEN, M. J. R. et al. Maternal obesity and fetal metabolic programming: a fertile
epigenetic soil. American Journal of Physiology-Regulatory, Integrative and
Comparative Physiology, v. 299, n. 3, p. R711–R722, set. 2010.
HOFFMAN, D. J. et al. Developmental Origins of Metabolic Disease. Physiological
Reviews, 3 dez. 2020.
HORIE, T. et al. MicroRNA-33 encoded by an intron of sterol regulatory element-binding
protein 2 (Srebp2) regulates HDL in vivo. Proceedings of the National Academy of
Sciences, v. 107, n. 40, p. 17321–17326, 5 out. 2010.
INSTITUTE FOR HEALTH METRICS AND EVALUATION (IHME). Findings from the
Global Burden of Disease Study 2017. Seattle: [s.n.].
JOUBERT, B. R. et al. DNA Methylation in Newborns and Maternal Smoking in
Pregnancy: Genome-wide Consortium Meta-analysis. American Journal of Human
Genetics, v. 98, n. 4, p. 680–696, 7 abr. 2016.
KIM, V. N.; HAN, J.; SIOMI, M. C. Biogenesis of small RNAs in animals. Nature Reviews
Molecular Cell Biology, v. 10, n. 2, p. 126–139, fev. 2009.
KROL, J.; LOEDIGE, I.; FILIPOWICZ, W. The widespread regulation of microRNA
biogenesis, function and decay. Nature Reviews. Genetics, v. 11, n. 9, p. 597–610, set.
2010.
KUMAR, M. S. et al. Dicer1 functions as a haploinsufficient tumor suppressor. Genes &
Development, v. 23, n. 23, p. 2700–2704, 1 dez. 2009.
KUO, P.-L. et al. MicroRNA-33a functions as a bone metastasis suppressor in lung cancer
by targeting parathyroid hormone related protein. Biochimica et Biophysica Acta (BBA)
- General Subjects, v. 1830, n. 6, p. 3756–3766, 1 jun. 2013.
KWON, D.-H. et al. Dietary protein restriction induces steatohepatitis and alters
leptin/signal transducers and activators of transcription 3 signaling in lactating rats. The
Journal of Nutritional Biochemistry, v. 23, n. 7, p. 791–799, jul. 2012.
59
LANDTHALER, M.; YALCIN, A.; TUSCHL, T. The human DiGeorge syndrome critical
region gene 8 and Its D. melanogaster homolog are required for miRNA biogenesis.
Current biology: CB, v. 14, n. 23, p. 2162–2167, 14 dez. 2004.
LEANDRO, C. G. et al. Maternal Moderate Physical Training during Pregnancy
Attenuates the Effects of a Low-Protein Diet on the Impaired Secretion of Insulin in Rats:
Potential Role for Compensation of Insulin Resistance and Preventing Gestational
Diabetes Mellitus. Journal of Biomedicine and Biotechnology, v. 2012, p. 1–7, 2012.
LEE, R. C.; FEINBAUM, R. L.; AMBROS, V. The C. elegans heterochronic gene lin-4
encodes small RNAs with antisense complementarity to lin-14. Cell, v. 75, n. 5, p. 843–
854, 3 dez. 1993.
LEE, Y. et al. The nuclear RNase III Drosha initiates microRNA processing. Nature, v.
425, n. 6956, p. 415–419, 25 set. 2003.
LEE, Y. et al. MicroRNA genes are transcribed by RNA polymerase II. The EMBO
journal, v. 23, n. 20, p. 4051–4060, 13 out. 2004.
LI, F.; ZHU, W.; GONZALEZ, F. J. Potential role of CYP1B1 in the development and
treatment of metabolic diseases. Pharmacology & Therapeutics, v. 178, p. 18–30, out.
2017.
LIMA, R. F. DE et al. Bisphenol-A promotes antiproliferative effects during neonatal
prostate development in male and female gerbils. Reproductive Toxicology, v. 58, p.
238–245, dez. 2015.
LIN, S.; GREGORY, R. I. MicroRNA biogenesis pathways in cancer. Nature Reviews
Cancer, v. 15, n. 6, p. 321–333, jun. 2015.
LIVAK, K.; SCHMITTGEN, T. Analysis of relative gene expression data using real-
time quantitative PCR and the 2(-Delta Delta C(T)) Method. Disponível em:
. Acesso em: 14 ago. 2020.
LOWSLEY, O. S. The development of the human prostate gland with reference to the
development of other structures at the neck of the urinary bladder. American Journal of
Anatomy, v. 13, n. 3, p. 299–349, 1912.
LU, Y. et al. Expression of semaphorin 6D and its receptor plexin-A1 in gastric cancer
and their association with tumor angiogenesis. Oncology Letters, v. 12, n. 5, p. 3967–
3974, nov. 2016.
LUCHINO, J. et al. Semaphorin 3E Suppresses Tumor Cell Death Triggered by the Plexin
D1 Dependence Receptor in Metastatic Breast Cancers. Cancer Cell, v. 24, n. 5, p. 673–
685, nov. 2013.
LUND, E. et al. Nuclear export of microRNA precursors. Science (New York, N.Y.), v.
303, n. 5654, p. 95–98, 2 jan. 2004.
60
MARKER, P. C. et al. Hormonal, cellular, and molecular control of prostatic development.
Developmental Biology, v. 253, n. 2, p. 165–174, 15 jan. 2003.
MARQUART, T. J. et al. miR-33 links SREBP-2 induction to repression of sterol
transporters. Proceedings of the National Academy of Sciences, v. 107, n. 27, p.
12228–12232, 6 jul. 2010.
MCMILLEN, I. C.; ADAM, C. L.; MÜHLHÄUSLER, B. S. Early origins of obesity:
programming the appetite regulatory system. The Journal of Physiology, v. 565, n. Pt
1, p. 9–17, 15 maio 2005.
MELO, S. A. et al. A genetic defect in exportin-5 traps precursor microRNAs in the nucleus
of cancer cells. Cancer Cell, v. 18, n. 4, p. 303–315, 19 out. 2010.
MERICQ, V. et al. Long-term metabolic risk among children born premature or small for
gestational age. Nature Reviews Endocrinology, v. 13, n. 1, p. 50–62, jan. 2017.
MIN, W. et al. The expression and significance of five types of miRNAs in breast cancer.
Medical Science Monitor Basic Research, v. 20, p. 97–104, 21 jul. 2014.
MOURELATOS, Z. et al. miRNPs: a novel class of ribonucleoproteins containing
numerous microRNAs. Genes & Development, v. 16, n. 6, p. 720–728, 15 mar. 2002.
MURALIDHAR, B. et al. Functional evidence that Drosha overexpression in cervical
squamous cell carcinoma affects cell phenotype and microRNA profiles. The Journal of
Pathology, v. 224, n. 4, p. 496–507, ago. 2011.
NÄÄR, A. M. miR-33: A Metabolic Conundrum. Trends in Endocrinology &
Metabolism, v. 29, n. 10, p. 667–668, out. 2018.
NAJAFI-SHOUSHTARI, S. H. et al. MicroRNA-33 and the SREBP Host Genes Cooperate
to Control Cholesterol Homeostasis. Science, v. 328, n. 5985, p. 1566–1569, 18 jun.
2010.
NUTRITION, N. R. C. (US) S. ON L. A. Nutrient Requirements of the Laboratory Rat.
[s.l.] National Academies Press (US), 1995.
OZANNE, S. E.; HALES, C. N. Catch-up growth and obesity in male mice. Nature, v. 427,
n. 6973, p. 411–412, jan. 2004.
PAN, S. et al. MicroRNA-130b and microRNA-374b mediate the effect of maternal dietary
protein on offspring lipid metabolism in Meishan pigs. British Journal of Nutrition, v.
109, n. 10, p. 1731–1738, 28 maio 2013.
PARASRAMKA, M. A. et al. A role for low-abundance miRNAs in colon cancer: the miR-
206/Krüppel-like factor 4 (KLF4) axis. Clinical Epigenetics, v. 4, n. 1, p. 16, 24 set. 2012.
61
PARL, F. F. et al. Estrogen Exposure, Metabolism, and Enzyme Variants in a Model for
Breast Cancer Risk Prediction. Cancer Informatics, v. 7, p. CIN.S2262, jan. 2009.
PELLETIER, D. L. et al. The Effects of malnutrition on child mortality in developing
countries. Bulletin of the World Health Organization 1995 ; 73(4) : 443-448, 1995.
PETRY, C. et al. Diabetes in Old Male Offspring of Rat Dams Fed a Reduced Protein
Diet. International journal of experimental diabetes research, v. 2, p. 139–43, 1 fev.
2001.
PIAN, C. et al. Discovering Cancer-Related miRNAs from miRNA-Target Interactions by
Support Vector Machines. Molecular Therapy - Nucleic Acids, v. 19, p. 1423–1433, 6
mar. 2020.
PINHO, C. F. et al. Gestational protein restriction delays prostate morphogenesis in male
rats. Reproduction, Fertility and Development, v. 26, n. 7, p. 967, 2014.
PLAGEMANN, A. et al. Hypothalamic neuropeptide Y levels in weaning offspring of low-
protein malnourished mother rats. Neuropeptides, v. 34, n. 1, p. 1–6, fev. 2000.
PORTELA, L. MF. et al. Increased oxidative stress and cancer biomarkers in the ventral
prostate of older rats submitted to maternal malnutrition. Molecular and Cellular
Endocrinology, v. 523, p. 111148, mar. 2021.
PRICE, N. L. et al. Genetic Ablation of miR-33 Increases Food Intake, Enhances Adipose
Tissue Expansion, and Promotes Obesity and Insulin Resistance. Cell Reports, v. 22, n.
8, p. 2133–2145, 20 2018.
PRINS, G. S. et al. Androgen receptor expression and 5 alpha-reductase activity along
the proximal-distal axis of the rat prostatic duct. Endocrinology, v. 130, n. 5, p. 3066–
3073, maio 1992.
PRINS, G. S. et al. Perinatal Exposure to Oestradiol and Bisphenol A Alters the Prostate
Epigenome and Increases Susceptibility to Carcinogenesis. Basic & clinical
pharmacology & toxicology, v. 102, n. 2, p. 134, fev. 2008.
PRINS, G. S.; PUTZ, O. Molecular signaling pathways that regulate prostate gland
development. Differentiation; Research in Biological Diversity, v. 76, n. 6, p. 641–
659, jul. 2008.
RAHMAN, R.-U. et al. Oasis 2: improved online analysis of small RNA-seq data. BMC
Bioinformatics, v. 19, n. 1, p. 54, 14 fev. 2018.
RAMOS, C. DA F. et al. The prostate of weaned pups is altered by maternal malnutrition
during lactation in rats. Asian Journal of Andrology, v. 12, n. 2, p. 180–185, mar. 2010.
62
RAVELLI, G. P.; STEIN, Z. A.; SUSSER, M. W. Obesity in young men after famine
exposure in utero and early infancy. The New England Journal of Medicine, v. 295, n.
7, p. 349–353, 12 ago. 1976.
RAVER-SHAPIRA, N. et al. Transcriptional activation of miR-34a contributes to p53-
mediated apoptosis. Molecular Cell, v. 26, n. 5, p. 731–743, 8 jun. 2007.
RAYNER, K. J. et al. MiR-33 Contributes to the Regulation of Cholesterol Homeostasis.
Science, v. 328, n. 5985, p. 1570–1573, 18 jun. 2010.
RAYNER, K. J. et al. Antagonism of miR-33 in mice promotes reverse cholesterol