Effect of glucose and insulin on the expression of TGF-β1 mRNA in Colon 26 Cells

Objective To study the effect of glucose and insulin on the expression of TGF-β1 mRNA in Colon 26 cells by mimicing the changes of glucose and insulin levels in different courses of diabetes mellitus.Methods Colon 26 tumor cells were cultured in vitro.According to the concentrations of glucose and insulin in culture medium,cells were divided into 12 groups: A group cultured with RPMI 1640 as control,B、C、D groups cultured with 5 mmol/L,10 mmol/L,25 mmol/L glucose respectively,E、F、G groups cultured with 5 μIU/ml、25 μIU/ml、125 μIU/ml insulin resprctively,while H group cultured with 5 mmol/L glucose and 5 μIU/ml insulin,K group cultured with 5 mmol/l glucose and 125 μIU/ml insulin,L group cultured with 25 mmol/L glucose and 125 μIU/ml insulin,M group cultured with 25 mmol/L glucose and 5 μIU/ml insulin,N group cultured with 25 mmol/l glucose and 1.25 μIU/ml insulin.There were 3 repeated holes in each group.After added to different culture media,cells were cultured for 48 h in saturated humidity incubator with 5%CO2 at 37 ℃.Expressions of TGF-β1 were detected by RT-PCR and were repeated three times.Results In D group,the level of TGF-β1 mRNA(0.768±0.017)was higher significantly than A(0.540±0.012,P0.01).However,expression of TGF-β1 in B and C group had no differences(0.545±0.033、0.558±0.035) compared with that in A group respectively(P0.05).Compared with group A,there was no statistical difference about the expression of TGF-β1 mRNA in Colon 26 cells in E,F and G groups(0.566±0.039、0.549±0.030、0.531±0.022,P0.05).In L,M and N groups,the level of TGF-β1 mRNA was higher(0.889±0.028、0.764±0.027、0.752±0.035) significantly than that of group A(P0.01).No differences were found in H and K groups(0.550±0.037、0.537±0.025) compared with A group(P0.05).Conclusion High concentration of glucose may up-regulate the expression of TGF-β1 mRNA in Colon 26 tumor cells.Different concentrations of insulin have no effects on the expression of TGF-β1 mRNA in Colon 26 tumor cells.High concentration of glucose and insulin may up-regulate the expression of TGF-β1 mRNA in Colon 26 tumor cells.