Obesity affects the growth of murine gastric cancer in mice / 西安交通大学学报(医学版)

ABSTRACT

Objective To explore the effects of obesity on the survival,growth and proliferation of gastric cancer and apoptosis by in vivo experiments so as to clarify the relationship between obesity and gastric cancer. Methods High fat diet-induced obese mice model was established.MFC cells were inoculated subcutaneously into mice to establish xenograft tumor model;then tumor growth and peritoneal metastasis were observed for 2 weeks. At the end of in vivo experiments,serum insulin and visfatin concentrations were assayed by ELISA,and blood glucose was determined by glucometer.MFC cell proliferation and apoptosis,as well as the number and size of adipocytes in xenograft tumor tissues were analyzed by immunohistochemistry, TUNEL and HE staining, respectively.Results High fat diet-induced obese mice model was successfully established within 12 weeks,and 66.7% of mice in the model were obese.Obese mice had distinct metabolic changes manifested as weight gain,high blood glucose,high serum visfatin,hyperinsulinemia and insulin resistance.All mice survived and developed no metastasis.The tumors from obese mice had a larger volume,heavier weight and greater intra-tumoral adipocytes, and exhibited higher proliferation and reduced apoptosis rate compared to those of non-obese and lean mice.Both serum insulin and visfatin concentrations correlated positively with tumor proliferation and negatively with tumor apoptosis.In addition,tumor weight showed a significantly positive correlation with mice body weight.Effects of diet-induced obesity on gastric cancer were not related to the influence of diet,but to the degree of obesity. Conclusion The altered adipocytokine milieu and insulin resistance observed in obesity may lead directly to alterations in tumor microenvironment,thereby promoting the survival and growth of gastric cancer.