Effect Of Metformin On Proliferation Of Human Pancreatic Cancer Cell Line Patu8988

Along with the rapid development of economy and the accelerated industrialization,non-communicable diseases have threatened human health increasingly heavier. Theprevalence and the total number of patients of diabetes are growing faster more surprising.This is a serious health problem we must face. Study found that the mortality of somecancers increased in patients with type2diabetes mellitus (T2DM) than normal people,such as colorectal cancer, liver cancer, breast cancer, pancreatic cancer and so on. Therelated mechanism has not yet cleared, but we have already confirmed that hyperglycemia,hyperinsulinemia, some growth factors (such as IGF-1, VEGF, TGF etc), advancedglycosylation end products (AGEs) are related to it.Metformin is the first choice in the treatment of diabetes. It through activating AMPactivating protein kinase (AMPK) signal system, reduces the gluconeogenesis in liver, andincreases the use of sugar in skeletal muscle, fat and other organizations, consequentlyblood sugar is reduced. Epidemiological studies found that the tumor prevalence rate indiabetes patients taking metformin was significantly lower than patients without metformin,and the risk of cancer deaths also significantly reduced. This suggests that metforminsomehow can reduce the occurrence or death of cancer. In recent years, studies have partlyrevealed the mechanism. AMPK signal transduction pathways is not only the importantpathway in energy metabolism regulation, playing a key role in energy balance in cells,also involved in the control of proliferation and apoptosis in cancer cells. Metformin actsdirectly on the tumor cells, and through activating tumor suppressor gene LKB1to activateAMPK, which can phosphorylate mammalian target of rapamycin protein (mTOR), andthrough the downstream molecular of mTOR to regulate tumor cell proliferation. For these, this experiment observated the variation of metformin on proliferation, cell cycle, and theexpression of related genes on pancreatic cancer cell lines, aimed to further exploring theeffect and the possible mechanism of metformin on tumor. Thus we can comprehensiveunderstand the important meaning of metformin on diabetes patients, especially ondiabetes patients with cancer.Objective To investigate the effect of metformin on the proliferation in humanpancreatic cancer cell line Patu8988, and to appraise the possible potential mechanism init.Method Human pancreatic cancer cell line Patu8988was treated with differentconcentrations of metformin, and the proliferation of Patu8988cells was measured by CellCounting Kit-8(CCK-8) assay at72h after treatment. The cell cycle changes wereanalyzed by flow cytometry(FCM). The expression of MMP-3, cyclingD1, Bax, Bcl-2, p53of Patu8988cells was detected by RT-PCR.Result Metformin suppressed the proliferation of Patu8988cells in a does-dependentmanner（r=0.994, P<0.05or P<0.01） after72h，and the values of absorbance in groupstreated with different concentrations of metformin (2.5,5,10,20,40mmol/L) were0.78±0.05,0.75±0.04,0.65±0.02,0.56±0.03,0.35±0.04, respectively, compared with0.82±0.02in control group. The effect was significantly in groups with metformin in10,20,40mmol/L (P<0.01). After treated with metformin (20mmol/L) for72h, thepercentages of cells in G0/G1phase were (29.16±6.72)%,(48.58±8.42)%in the controlgroup and the intervention group, in S phase were(61.41±1.42)%,(47.77±7.19)%, and inG2/M phase were (9.42±5.31)%,(3.56±3.71)%. RT-PCR results showed that theexpression of MMP-3, CyclinD1, p53genes were down-regulation, during the expressionof Bax and Bcl-2were up-regulate and no change after treated with metformin.Conclusions1. Metformin can inhibit the proliferation of pancreatic cancer cell line Patu8988,suggests that metformin not only lower blood sugar, may also suppress tumor. 2. Metformin can inhibit the cell cycle and down-regulate the expression of MMP-3,CyclinD1, p53gene and up-regulate Bax expression in Patu8988cells, shows thatmetformin plays a direct role from gene level to tumor cells.3. Metformin can influence tumor cell proliferation by blocking the cell cycle, adjustthe expression of cycle and apoptosis related genes, and plays anti-tumor effect.