Effects Of Metformin On Proliferation，Cycle And Apoptosis Of Colon Cancer Cell SW480

ObjectiveThis study was designed to observe the effect of metformin on theproliferation, cycle and apoptosis of human colon cancer cell SW480, and toexplore the mechanism that meformin inhibit the cancer cell proliferation andinduced apoptosis.Methods1、SW480cells were cultured in vitro, cell morphology of SW480cells wasobserved by inverted microscope.2、The effect of different concentrations metformin on the proliferation ofSW480cells was measured by MTT assay.3、The effect of metformin on cell cycle and apoptosis of SW480cells wereanalyzed by FCM.4、The effect of metformin on the expressions of CyclinD1, P27, Bcl-2, Baxand Caspase3mRNA in SW480cells were detected by real time fluorescentquantitative PCR.Results1、As exposed to inverted microscope, compared to control, SW480cellswith metformin took on malignance declining as crimpled firstly, cellular bulk diminished. With the concentration of metformin increasing, the amounts ofadherent cells decreased and rounded cells increased, subsequently partialrounded cells were floated.2、MTT analysis reveals that the proliferation inhibition effect of themetformin(1mmol/L,5mmol/L,10mmol/L,20mmol/L,40mmol/L) on SW480cells for24，48,72h exhibited a dose-and time-dependent manner.3、FCM analysis reveals that after exposed to20mmol/L metformin for48h,compared with the control, cells at G0/G1stage were increased(P<0.05),cells at S stage were decreased(P<0.05), no significant difference of G2/M stagecells (P>0.05). Simultaneously, metformin has significant effect of inducingSW480cells apoptosis(P<0.01).4、Real time fluorescent quantitative-PCR analysis reveals that theexpressions of CyclinD1and Bcl-2mRNA were both down-regulated after20mmol/L metformin treatment for48h(P<0.01), while Caspase3and BaxmRNA expressions were up-regulated(P<0.01). No significant difference of P27expression(P>0.05) was obesrved.ConclusionsMetformin can inhibit the proliferation, block the cell cycle at G0/G1stage,and induce the apoptosis of SW480cells in vitro, which may partly be attributedto the down-regulating CyclinD1, Bcl-2mRNA and up-regulating Caspase3, BaxmRNA expressions.