Effects Of Metformin On The Expression Of Adiponectin In Endometrial Cancer Cell Lines

Background and ObjectiveEndometrial cancer is a common gynecologic malignancy, accounting for about 7% of female cancer patients, and its incidence is on the rise in recent years, serious harming to women’s health. At present, the tumor pathogenesis is still unclear, the risk factors include obesity, diabetes, hypertension and polycystic ovary syndrome(PCOS) and so on. Epidemiological data show that obesity is a risk factor for endometrial cancer,in particular upper abdominal obesity. Obese people have more adipose tissue and adipokines than normal in the body, but adiponectin level is lower. Epidemiological research has demonstrated that adiponectin was negative association with endometrial cancer.And adiponectin through its specific receptors,inhibits cell proliferation,and promotes cell apoptosis, which may be one of its anti-tumor mechanism.There are a wealth of transcription factor binding sites in upstream promoter of adiponectin gene. FOXO1(forkhead box protein O1) through the combination of C / EBP(CCAAT enhancer binding protein) enhances transcription of adiponectin gene.Recent studies have found that Metformin,the first-line treatment of type 2 diabetes drug, corrects insulin resistance in patients and affects the occurrence and development of endometrial cancer.And this effect is achieved through the AMPK signaling pathway.Therefore, this study was to investigate whether the metformin can increase the level of FOXO1 thereby increasing expression of adiponectin by AMPK / m TORC1 in the endometrial carcinoma cell line HEC-1A and Ishikawa, providing new ideas for diagnosis and treatment of endometrial cancer. MaterialIn this paper, endometrial cancer cell line HEC-1A(meoderately differentiation) and Ishikawa(IK, well-differentiated) were taked as experimental subjects, which were presented by Professor Wei Lihui(the Obstetrics and Gynecology Laboratory of Peking University People’s Hospital),respectively, cultured in containing 10% fetal bovine serum DMEM- high sugar and DMEM / F12 medium, placed in 37 ℃, 5% CO2 incubator. The cell lines were routinely passaged. Methords1.The CCK8 assay detected the proliferation rate of HEC-1A and Ishikawa after metformin treating with different concentrations and at different times.2.The changes in adiponectin m RNA expression levels were disclosed metformin affecting with different concentrations in HEC-1A and Ishikawa by RT-PCR3.Western Blot detected the expression of FOXO1 and adiponectin at different concentrations of metformin in HEC-1A and Ishikawa Results1.There were declines in the growth rates of HEC-1A and Ishikawa cell lines after the 24 hours treatment of metformin with the concentrations of 0 mmol / L, 10 mmol / L, 15 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol / L, FHEC-1A=57.74,PHEC-1A<0.05,FIshikawa=121.63,PIshikawa<0.05,and the significant differences between each group at a dose-dependent manner2.After metformin handling with the concentrations of 0 mmol / L, 10 mmol / L, 15 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol L in 24 hours, RT-PCR detected the decreases of the expression levels of adiponectin m RNA after the first increase, in HEC-1A and Ishikawa cell lines,the maximum at the concentration of 20 mmol / L or so. Among groups the differences were statistically significant, P <0.05,3.After the 24 hours treatment of metformin with the concentrations of 0 mmol / L, 10 mmol / L, 15 mmol / L, 20 mmol / L, 25 mmol / L, 30 mmol /, Western Blot detected the increasing expression of adiponectin and FOXO1 protein in HEC-1A and Ishikawa cell lines. Comparison between the various concentrations, the differences were statistically significant,P <0.05. ConclusionMetformin can inhibit the proliferation of endometrial cells in a dose-dependent, and increase the level of expression of adiponectin m RNA and protein, and its mechanism may be related with the upregulation content of FOXO1.