Effects Of Silencing HIF-1α On The Bionomics Of Human Colon Cancer Cells SW480

Objective: Previous studies with respect to clinic have proven that the gene express of HIF-1α showed the close correlation with clinical characteristics in patients with colon caner. In view of this, this study was undertaken to investigate the change of bionomics of human colon cancer cells SW480 after HIF-1α silencing using the methods of the si RNA interference technology via transfection with lipofectamine mediation to transfect si RNA into human colon cancer cells SW480. Methods: We use lipofectamine mediation to transfect si RNA into human colon cancer cells SW480 to silence the express of HIF-1α. In addition, we divided the cell line into four groups with the name of interference group, negative control group, the empty vector group and blank control group according to the difference of transfect. Henceforth, we use the Real-time PCR method to evaluate the expression of HIF-1α in cell line and calculated the silence rate. We use the Western-blot method to evaluate the expression of HIF-1α in protein level. We also use the MTT method to evaluate the proliferation of cell lines and luminometer method to evaluate the concentration of ATP in cell lines and FCM to evaluate the apoptosis in cell lines.Results: The silence rate of HIF-1αin interference group(>80%) was significant higher than those of in other three groups(<6%); it demonstrated that the expression of HIF-1α were inhibited and to be in line with experimental design. The relative expressions of HIF-1α in interference group, negative control group, the empty vector group and blank control group in different times have the significant difference with respect to HIF-1α were detected among the four groups(F=12.473,p=0.012). The expression of protein of HIF-1α in interference group was lower than those of in other groups. However, there are no differences among negative control group, the empty vector group and blank controlgroup. There are significant differences on the OD values of SW480 cells were observed among the four groups. The OD value in interference group was significant higher than that of in negative control group. The trend of proliferate of cells was inhibited with the time. The early apoptosis rates in interference group, negative control group, the empty vector group and blank control group were 45.36%、4.43、3.48%、3.41%, respectively, and the advanced stage apoptosis rates in the four groups were 22.92%、4.75%、3.65%、3.74%, respectively. The apoptosis rates of early and advanced stage were higher in interference group than those of in other three groups(all P values <0.05). However, there are no differences were observed among the negative control group, the empty vector group and blank control group. The ATP concentrations of SW480 cells showed differences in different timepoints and groups. In addition, ATP level in interference group was lower than other three groups on 1 to 5 days after culture, and there are no difference among other three groups. In addition, the time-dependent decrease of ATP level can be observed in every group. Conclusion: The methods of the si RNA interference technology via transfection with lipofectamine mediation to transfect si RNA into human colon cancer cells SW480 can effectively silence the expression of HIF-1α in m RNA and protein level. Silencing HIF-1α can inhibit proliferation of SW480 and these inhibited effects are time-dependent. Silencing HIF-1α can promote the apoptosis of cell lines in early and late stage. Silencing HIF-1α can decrease the ATP level and this kind of decrease is time-dependeng.