Clinical studies have revealed that social support improves the outcome of cancer patients, whereas epidemiologic studies suggest that social isolation increases the risk of death associated with several chronic diseases. However, the precise molecular consequences of an unfavorable social environment have not been defined. To do so, robust, reproducible preclinical models are needed to study the mechanisms whereby an adverse environment affects gene expression and cancer biology. Because random assignment of inbred laboratory mice to well-defined social environments allows accurate and repeated measurements of behavioral and endocrine parameters, transgenic mice provide a preclinical framework with which to begin to determine gene-environment mechanisms. In this study, we found that female C3(1)/SV40 T-antigen mice deprived of social interaction from weaning exhibited increased expression of genes encoding key metabolic pathway enzymes in the premalignant mammary gland. Chronic social isolation was associated with up-regulated lipid synthesis and glycolytic pathway gene expression—both pathways are known to contribute to increased breast cancer growth. Consistent with the expression of metabolic genes in premalignant mammary tissue, isolated mice subsequently developed a significantly larger mammary gland tumors burden compared with group-housed mice. Endocrine evaluation confirmed that isolated mice developed a heightened corticosterone stress response compared with group-housed mice. Together, these transdisciplinary studies show for the first time that an adverse social environment is associated with altered mammary gland gene expression and tumor growth. Moreover, the identification of specific alterations in metabolic pathways gene expression favoring tumor growth suggests potential molecular biomarkers and/or targets (e.g., fatty acid synthesis) for preventive intervention in breast cancer.

Background: FoxO1 regulates expression of lipogenic genes including srebp1. Results: FoxO1 inhibits transcription of SREBP-1c via coordinated effects on key regulatory factors including Sp1 and SREBP-1c itself. Conclusion: FoxO1 acts at multiple levels to prevent assembly of the transcriptional complex on the srebp1 gene. Significance: FoxO1 effectively inhibits SREBP-1c gene expression, a major regulator of hepatic lipogenesis.

No abstract

of TAC required to achieve therapeutic levels was approximately 2 fold higher than the starting dose, representing an opportunity to optimize initial dosing. Conclusions: Early, therapeutic TAC levels have been associated with improved outcomes in renal transplant recipients. In an analysis of 40 heart transplant recipients receiving only methylprednisolone induction, there was not an apparent impact on 12 month incidence of treated rejection with regards to time to therapeutic levels, CV, and therapeutic TAC dose. A high CV was observed in our population; a CV greater than 15% has been associated with increased risk of rejection and poor outcomes among renal transplant recipients, however outcomes were no different in our cohort.