美国科研人员通过老鼠实验发现，离群索居会使雌性哺乳动物更容易罹患乳腺癌。
美国芝加哥大学科研人员日前发布公报称，他们先将易引发乳腺癌的基因植入实验用雌鼠体内，然后将这些实验鼠分为两组，一组实验鼠被分别置于隔离环境中，另一组则被置于集体环境中。一段时间后科研人员发现，与另一组实验鼠相比，处于隔离环境的实验鼠体内出现了数量更多、体积更大的乳腺肿瘤。进一步研究发现，独居实验鼠的乳腺组织基因表达发生了变化，而这种变化会促使肿瘤的生长。
科研人员因此得出结论，与集体环境中的实验鼠相比，离群索居的实验鼠更容易罹患乳腺癌。由于实验鼠的身体机能与人类相似，这一结论同样适用于人类。
研究人员表示，这项研究说明社会环境确实可以改变患者体内多种组织的基因表达，而不只是脑部组织。对人类基因组加深了解，有助于更有效地预防乳腺癌等疾病。（生物谷Bioon.com）
生物谷推荐原始出处：
Cancer Prevention Research 2, 850, October 1, 2009.doi: 10.1158/1940-6207.CAPR-08-0238
A Model of Gene-Environment Interaction Reveals Altered Mammary Gland Gene Expression and Increased Tumor Growth following Social Isolation
J. Bradley Williams1, Diana Pang1, Bertha Delgado2,3, Masha Kocherginsky4, Maria Tretiakova2, Thomas Krausz2, Deng Pan1, Jane He1, Martha K. McClintock3 and Suzanne D. Conzen1,3,5
Authors' Affiliations: Departments of 1 Medicine and 2 Pathology, 3 The Institute of Mind and Biology, 4 Department of Health Studies, and 5 Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois
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.
