Inhibitory Effect Of Small Interfering RNA Targeting SIRT1 On Proliferation Of Cervical Cancer C33A Cells

Objective: To detect the expression of SIRT1 in human cervical cancer C33 A cells and the effect of SIRT1 on the cell proliferation, migration, invasion, apoptosis and Notch signaling pathway, as to explore the mechanisms of SIRTl in the development of cervical cancer.Methods: Chemical synthesis of small interfering RNA(si RNA) specific to SIRT1 gene were transfected by Lipofectmine RNAi MAX liposomes into cervical cancer C33 A cells which were divided into four groups: SIRT1-si RNA groups, SIRT1 negative control group, RNAi MAX control group and normal cell group. 72 h after transfection, the total RNA and protein were extracted respectively, the expression of SIRT1 m RNA level was detected by RT-PCR, and the expression of SIRTl, Notch1,Hes1 protein were analyzed by Western blot. The cell proliferation was measured by CCK-8 method, the migration and invasion of C33 A cells were determined by Transwell chambers assay, the apoptosis was assessed by Annexin-V staining and Hoechst 33258 fluorochrome staining respectively.Results: RT-PCR results showed that the m RNA expression of si RNA-SIRT1 group was significantly down-regulated(P<0.05) compared to the control groups. Western blot indicated that the expression level of SIRT1 protein in the SIRT1-si RNA group was significantly down-regulated(P<0.05), the expression of Notch1 and Hes1 proteins were up-regulated(P < 0.05), while the other three groups had no significant changes(P>0.05). CCK-8 proliferation assay revealed that the inhibition rate of SIRT1-si RNA group was 53.1%, while the negative control group was 35.4%, the inhibition rate of RNAi MAX control group was 11.5%. The inhibition rate of SIRT1-si RNA group was significantly higher than other groups. The Transwell chambers assays displayed that the amounts of C33 A cells passing the artificial basement membrane in the SIRT1-si RN group was significantly decreased compared to the SIRT1 negative control group, RNAi MAX group and normal cell group groups. Flow cytometry displayed that the SIRT1-si RNA cells apoptosis rate was significantly higher than that in the control groups, RNAi MAX group and normal cell group. Hoechst33258 staining indicated the nucleus of C33 A cells decreased, the chromatin condensed, and apoptotic bodies appeared, while the cell nuclei in the control groups were pale blue uniform.Conclusion: Chemically synthesized small interference RNA specific to SIRT1 not only inhibited the proliferation, migration and invasion of C33 A cells but also induced apoptosis in C33 A cells, which was associated with Notch-hes signaling pathways.