Genistein Reduces the Risk of Local Mammary Cancer Recurrence and Ameliorates Alterations in the Gut Microbiota in the Offspring of Obese Dams.

The risk of recurrence of estrogen receptor-positive breast cancer remains constant, even 20 years after diagnosis. Recurrence may be more likely in patients pre-programmed for it already in the womb, such as in the daughters born to obese mothers. Maternal obesity persistently alters offspring's gut microbiota and impairs tumor immune responses. To investigate if the gut dysbiosis is linked to increased risk of mammary cancer recurrence in the offspring of obese rat dams, we fed adult offspring genistein which is known to have beneficial effects on the gut bacteria. However, the effects of genistein on breast cancer remain controversial. We found that genistein intake after tamoxifen response prevented the increased risk of local recurrence in the offspring of obese dams but had no effect on the control offspring. A significant increase in the abundance of inflammatory Prevotellaceae and Enterobacteriaceae, and a reduction in short-chain fatty acid producing Clostridiaceae was observed in the offspring of obese dams. Genistein supplementation reversed these changes as well as reversed increased gut metabolite N-acetylvaline levels which are linked to increased all-cause mortality. Genistein supplementation also reduced genotoxic tyramine levels, increased metabolites improving pro-resolving phase of inflammation, and reversed the elevated tumor mRNA expression of multiple immunosuppressive genes in the offspring of obese dams. If translatable to breast cancer patients, attempts to prevent breast cancer recurrences might need to focus on dietary modifications which beneficially modify the gut microbiota.

Dietary zinc deficiency or supplementation during gestation increases breast cancer susceptibility in adult female mice offspring following a J-shaped pattern and through distinct mechanisms.

Zinc is required for fetal development and is involved in key processes associated with breast carcinogenesis. We evaluated whether maternal zinc deficiency or supplementation during gestation influences female offspring susceptibility to breast cancer in adulthood. C57BL/6 mice consumed during gestation control (30 p.p.m. zinc), zinc-deficient (8 p.p.m) or zinc-supplemented (45 p.p.m.) diets. Maternal zinc supplementation increased in female mice offspring the incidence of chemically-induced mammary adenocarcinomas that were heavier, compared to control group. This was accompanied by a decreased number of terminal end buds, increased cell proliferation and apoptosis, and increased tumor suppressors p21, p53 and Rassf1, Zfp382 and Stat3 expression in mammary glands, as well as increased zinc status. Although maternal zinc deficiency did not alter the incidence of these lesions, it also induced heavier mammary adenocarcinomas, compared to control group. These effects were accompanied by a decreased number of terminal end buds, increased proto-oncogenes c-Myc and Lmo4 expression and H3K9Me3 and H4K20Me3 epigenetic marks in mammary glands of offspring, and decreased zinc status and increased levels of oxidative marker malondialdehyde. The data suggest that both maternal zinc deficiency and supplementation during gestation programmed increased breast cancer susceptibility in adult mice offspring following a J-shaped pattern through distinct mechanisms.

ß-ionone modulates the expression of miRNAs and genes involved in the metastatic phenotype of microdissected persistent preneoplastic lesions in rats submitted to hepatocarcinogenesis.

MicroRNAs (miRNAs) are post-transcriptional gene expression regulators which expression is frequently altered in hepatocellular carcinoma (HCC). ß-ionone (ßI) is noted for its ability to inhibit persistent preneoplastic lesions (pPNLs) in liver rats. We evaluated the expression of miRNAs involved in carcinogenesis and possible targets modulated by ßI, in pPNLs and surrounding of microdissected tissues. Rats subjected to resistant hepatocyte model were treated during promotion stage with ßI (16 mg/100 g body weight) or corn oil (CO; 0.25 mL/100 g body weight; controls). Five animals receive no treatment (NT). In CO group, 38 and 29 miRNAs showed reduced expression relative to NT (P < 0.05) in pPNLs and surrounding, respectively. No miRNAs showed increased expression in surrounding of the CO compared to NT group; however, 30 miRNAs showed increased expression (P ≤ 0.05) in pPNLs of the CO group. There was no difference between ßI and CO groups (P > 0.05) in the expression of miRNAs in surrounding. In pPNLs ßI increased expression of miR-122 and miR-34a (P ≤ 0.05) and reduced of Igf2 (P ≤ 0.05), target of the latter, compared to CO. Additionally, ßI decreased the expression of miR-181c and its target Gdf2 (P ≤ 0.05). ßI reduced the expression of miR-181b and miR-708 (P ≤ 0.05) and increased the expression of their respective target mRNAs Timp3 and Mtss1 (P ≤ 0.05), relative to CO group. Modulation of miRNAs target genes by ßI was confirmed in vitro. ßI is a promising chemopreventive agent in the initial stages of hepatocarcinogenesis, as it modulates the expression of the miRNAs and target genes that can alter the metastatic phenotype of HCC. © 2016 Wiley Periodicals, Inc.

Paternal programming of breast cancer risk in daughters in a rat model: opposing effects of animal- and plant-based high-fat diets.

BACKGROUND: Although males contribute half of the embryo's genome, only recently has interest begun to be directed toward the potential impact of paternal experiences on the health of offspring. While there is evidence that paternal malnutrition may increase offspring susceptibility to metabolic diseases, the influence of paternal factors on a daughter's breast cancer risk has been examined in few studies. METHODS: Male Sprague-Dawley rats were fed, before and during puberty, either a lard-based (high in saturated fats) or a corn oil-based (high in n-6 polyunsaturated fats) high-fat diet (60 % of fat-derived energy). Control animals were fed an AIN-93G control diet (16 % of fat-derived energy). Their 50-day-old female offspring fed only a commercial diet were subjected to the classical model of mammary carcinogenesis based on 7,12-dimethylbenz[a]anthracene initiation, and mammary tumor development was evaluated. Sperm cells and mammary gland tissue were subjected to cellular and molecular analysis. RESULTS: Compared with female offspring of control diet-fed male rats, offspring of lard-fed male rats did not differ in tumor latency, growth, or multiplicity. However, female offspring of lard-fed male rats had increased elongation of the mammary epithelial tree, number of terminal end buds, and tumor incidence compared with both female offspring of control diet-fed and corn oil-fed male rats. Compared with female offspring of control diet-fed male rats, female offspring of corn oil-fed male rats showed decreased tumor growth but no difference regarding tumor incidence, latency, or multiplicity. Additionally, female offspring of corn oil-fed male rats had longer tumor latency as well as decreased tumor growth and multiplicity compared with female offspring of lard-fed male rats. Paternal consumption of animal- or plant-based high-fat diets elicited opposing effects, with lard rich in saturated fatty acids increasing breast cancer risk in offspring and corn oil rich in n-6 polyunsaturated fatty acids decreasing it. These effects could be linked to alterations in microRNA expression in fathers' sperm and their daughters' mammary glands, and to modifications in breast cancer-related protein expression in this tissue. CONCLUSIONS: Our findings highlight the importance of paternal nutrition in affecting future generations' risk of developing breast cancer.

Influência da deficiência ou suplementação com selênio durante o período gestacional de ratas na suscetibilidade da progênie feminina à carcinogênese mamária / Influence of selenium deficiency or supplementation during rat gestational period on the susceptibility of female offspring to mammary carcinogenesis

Fatores dietéticos como o selênio (Se) são apontados como importantes moduladores do risco de desenvolvimento do câncer de mama. Essa neoplasia pode apresentar sua origem no início do desenvolvimento e, assim, a alimentação materna poderia ter importantes repercussões na programação fetal da doença. A fim de verificar se diferentes concentração de selênio na dieta materna poderiam programar o risco da progênie feminina ao câncer de mama, ratas foram alimentadas com ração contendo 0,15 (CO), 1,0 (SUP) ou 0,05 (DEF) ppm de Se durante a gestação e sua progênie feminina iniciada com DMBA. A progênie do grupo SUP apresentou menor suscetibilidade à carcinogênese, indicado pelo menor número médio e multiplicidade de adenocarcinomas mamários (p< 0,05), enquanto a do grupo DEF apresentou maior suscetibilidade à carcinogênese, indicado pela maior incidência dos mesmos (p< 0,05). Mães do grupo DEF apresentaram menor concentração de Se no sangue (p< 0,05) e sua prole apresentou menor atividade da enzima GPx1 (p< 0,05). Além disso, observou-se na glândula mamária da progênie de 50 dias menor expressão (western blot e qPCR) de ERα, Her-2, EGFR e Ras no grupo SUP em comparação aos grupos CO e DEF (p< 0,05). Analisou-se, ainda, o padrão de metilação global do DNA (HPLC-DAD), expressão das enzimas DNMT1, 3a e 3b (qPCR), o padrão global de modificações pós traducionais em histonas (western blot) e o padrão de metilação da região promotora do gene Erα (modificação com bissulfito e pirossequenciamento) na glândula mamária da progênie de 50 dias. Não houve diferença no padrão de metilação global do DNA e expressão das enzimas DNMTs (p>0,05). Houve aumento na expressão de H4K16 acetilada nos grupos SUP e DEF (p< 0,05). Finalmente, em comparação a progênie do grupo DEF, a do grupo SUP apresentou região promotora de Erα com aumento marginal (p=0,07) na metilação de dois dinucleotídeos CpG. Conclui-se que o consumo de diferentes concentrações de Se na dieta materna tem impacto sobre a suscetibilidade da progênie ao câncer de mama na vida adulta através da modulação da expressão de receptores e oncogenes relacionados ao desenvolvimeto dessa neoplasia, além da influência em processos epigenéticos. Tais resultados apontam para a existência de uma "janela de programação" no início do desenvolvimento sensível a ação do Se, resultando em diminuição do risco de câncer de mama quando suplementado na dieta materna e o inverso quando de sua deficiencia

Based on epidemiological studies and animal models, the essential micronutrient selenium has been highlighted as a promising dietary factor associated to breast cancer risk reduction. Breast cancer may have its origin in early development and thus the maternal diet could have important implications in the fetal programming of the disease. In order to ascertain whether differences in selenium concentration in maternal diet could modulate the susceptibility of female offspring to breast cancer, a biological assay was conducted in which female rats were fed a diet with 0.15 (CO), 1.0 (SUP) or 0.05 (DEF) ppm of selenium during gestational period and the female offspring subjected to a mammary carcinogenesis model induced by DMBA. SUP group offspring presented decreased susceptibility to mammary carcinogenesis, as indicated by lower (p< 0,05) average number and multiplicity od adenocarcinomas, while the DEF group offspring had a greater susceptibility, as indicated by the increase (p< 0,05) in adenocarcinomas incidency. Mothers of the DEF group pesented lower (p< 0,05) Se blood concetrations and their offspring presented lower (p<0,05).GPx1 activity. In addition, there was a decrease (p< 0,05) in ERα, Her-2, EGFR and Ras expression (western blot and qPCR) in the mammary gland of 7 weeks old female SUP group offspring when compared to CO and DEF groups offspring. DNA global methylation pattern (HPLC-DAD), DNMT1, 3a e 3b expression (qPCR), global pattern of post-translational modification in histones (western blot) and methylation status of Erα promoter region (bisulfite modification and pyrosequencing) were also evaluated in the mammary gland of 7 weeks old offspring. There was no diffrence (p>0,05) in DNA global methylation pattern and DNMTs expression. There was an increase in acetilated H4K16 expression in groups SUP and DEF (p< 0,05). Lastly, when compared to DEF offspring, the SUP offspring presented a marginal increase in the methylation of two CpG dinucleotides in the Erα promoter region. In conclusion, the consumption of different selenium concentration in maternal diet plays a role in the progeny's breast cancer susceptibility through the modulation of receptors and oncogenes expression, in addition to modifications in epigenetic patterns. These results indicate the presence of a "programming window" in the beggining of development susceptible to selenium effects, resulting in decreased breast cancer risk when supplemented and the opposite when deficient

Exposure to lard-based high-fat diet during fetal and lactation periods modifies breast cancer susceptibility in adulthood in rats.

The present study investigated whether early life exposure to high levels of animal fat increases breast cancer risk in adulthood in rats. Dams consumed a lard-based high-fat (HF) diet (60% fat-derived energy) or an AIN93G control diet (16% fat-derived energy) during gestation or gestation and lactation. Their 7-week-old female offspring were exposed to 7,12-dimethyl-benzo[a]anthracene to induce mammary tumors. Pregnant dams consuming an HF diet had higher circulating leptin levels than pregnant control dams. However, compared to the control offspring, significantly lower susceptibility to mammary cancer development was observed in the offspring of dams fed an HF diet during pregnancy (lower tumor incidence, multiplicity and weight), or pregnancy and lactation (lower tumor multiplicity only). Mammary epithelial elongation, cell proliferation (Ki67) and expression of NFκB p65 were significantly lower and p21 expression and global H3K9me3 levels were higher in the mammary glands of rats exposed to an HF lard diet in utero. They also tended to have lower Rank/Rankl ratios (P=.09) and serum progesterone levels (P=.07) than control offspring. In the mammary glands of offspring of dams consuming an HF diet during both pregnancy and lactation, the number of terminal end buds, epithelial elongation and the BCL-2/BAX ratio were significantly lower and serum leptin levels were higher than in the controls. Our data confirm that the breast cancer risk of offspring can be programmed by maternal dietary intake. However, contrary to our expectation, exposure to high levels of lard during early life decreased later susceptibility to breast cancer.