Parental obesity programs pancreatic cancer development in offspring.

Epidemiological studies suggest that timing of obesity onset - and underlying metabolic dysfunction - is important in determining pancreatic cancer rates: early and young adult abdominal overweight/obesity is more strongly associated with this cancer than obesity that develops later in life. Parental obesity and overweight are associated with metabolic dysfunction and obesity in their children. Here, we evaluated the impact of parental overweight on offspring's susceptibility of pancreatic cancer using the P48Cre/+/KrasG12D/+ mouse model. Male mice were fed an obesity-inducing diet (OID) before conception and mated with females raised on a control diet (CO) to generate the offspring. In a separate experiment, pregnant dams were fed CO or OID throughout gestation. The resulting OID offspring from the maternal (OID-m) or paternal lineage (OID-p) were used to study body weight, metabolic parameters and pancreatic cancer development and for molecular analysis. Parental obesity increased offspring's body weight at birth, weaning and in adulthood compared to CO, with gender- and genotype-specific differences. OID-p and OID-m offspring showed metabolic disorder and accelerated development of high-grade PanIN/PDAC. OID offspring also had higher rates of acinar-to-ductal reprogramming assessed by CPA1+/SOX9+-positive pancreatic cells. Levels of Tenascin C (TNC), an ECM glycoprotein shown to suppress apoptosis, were elevated in OID offspring, particularly females. In line with that, OID offspring displayed increased collagen content and decreased apoptosis in pancreatic lesions compared to CO. An ancestral history of obesity through either the paternal or maternal lineages increases offspring's susceptibility to pancreatic cancer development.

Paternal malnutrition programs breast cancer risk and tumor metabolism in offspring.

BACKGROUND: While many studies have shown that maternal factors in pregnancy affect the cancer risk for offspring, few studies have investigated the impact of paternal exposures on their progeny's risk of this disease. Population studies generally show a U-shaped association between birthweight and breast cancer risk, with both high and low birthweight increasing the risk compared with average birthweight. Here, we investigated whether paternal malnutrition would modulate the birthweight and later breast cancer risk of daughters. METHODS: Male mice were fed AIN93G-based diets containing either 17.7% (control) or 8.9% (low-protein (LP)) energy from protein from 3 to 10 weeks of age. Males on either group were mated to females raised on a control diet. Female offspring from control and LP fathers were treated with 7,12-dimethylbenz[a]anthracene (DMBA) to initiate mammary carcinogenesis. Mature sperm from fathers and mammary tissue and tumors from female offspring were used for epigenetic and other molecular analyses. RESULTS: We found that paternal malnutrition reduces the birthweight of daughters and leads to epigenetic and metabolic reprogramming of their mammary tissue and tumors. Daughters of LP fathers have higher rates of mammary cancer, with tumors arising earlier and growing faster than in controls. The energy sensor, the AMP-activated protein kinase (AMPK) pathway, is suppressed in both mammary glands and tumors of LP daughters, with consequent activation of mammalian target of rapamycin (mTOR) signaling. Furthermore, LP mammary tumors show altered amino-acid metabolism with increased glutamine utilization. These changes are linked to alterations in noncoding RNAs regulating those pathways in mammary glands and tumors. Importantly, we detect alterations in some of the same microRNAs/target genes found in our animal model in breast tumors of women from populations where low birthweight is prevalent. CONCLUSIONS: Our study suggests that ancestral paternal malnutrition plays a role in programming offspring cancer risk and phenotype by likely providing a metabolic advantage to cancer cells.

Paternal overweight is associated with increased breast cancer risk in daughters in a mouse model.

While many studies have shown that maternal weight and nutrition in pregnancy affects offspring's breast cancer risk, no studies have investigated the impact of paternal body weight on daughters' risk of this disease. Here, we show that diet-induced paternal overweight around the time of conception can epigenetically reprogram father's germ-line and modulate their daughters' birth weight and likelihood of developing breast cancer, using a mouse model. Increased body weight was associated with changes in the miRNA expression profile in paternal sperm. Daughters of overweight fathers had higher rates of carcinogen-induced mammary tumors which were associated with delayed mammary gland development and alterations in mammary miRNA expression. The hypoxia signaling pathway, targeted by miRNAs down-regulated in daughters of overweight fathers, was activated in their mammary tissues and tumors. This study provides evidence that paternal peri-conceptional body weight may affect daughters' mammary development and breast cancer risk and warrants further studies in other animal models and humans.