Effect Of Silencing SIRT1 On The Biological Behaviors Of TPC-1 In Human Thyroid Papillary Carcinoma Cell Line

Objective To investigate the effect of silent SIRT1 gene on the biological behaviors of human thyroid papillary carcinoma cell line TPC-1.In this study,the SIRT1 gene was interfered by SIRT1 si RNA and its expression in TPC-1 cells was silenced.At the same time,the effects of SIRT1 on the biological behaviors of TPC-1 were studied by detecting the changes in cell proliferation,senescence,apoptosis,and cycle.Through the above studies to further explore the role of SIRT1 in the development and progression of TPC.Methods 1.SIRT1 si RNA was used to down-regulate the expression of SIRT1 in thyroid papillary carcinoma cell line TPC-1.SIRT1 si RNAs with different concentrations and different sequences were used to transfect human thyroid papillary carcinoma cell line TPC-1 in vitro,which interfered with the expression of SIRT1 in TPC-1.At the same time,the interference efficiency of SIRT1 si RNA was detected by q RT-PCR,and the SIRT1 si RNA with the strongest interference efficiency was screened out.Western blot was used to verify the expression of SIRT1 protein.2.Each experiment was divided into 3 groups: TPC-1 cells treated with SIRT1 si RNA as an experimental group（SIRT1 si RNA group）,TPC-1 cells treated with NC si RNA as a negative control group（NC si RNA group）and TPC-1 cells without treated as a blank control group（TPC-1）.CCK8 method was used to detect the proliferation of TPC-1 cells on days 1 to 3 in these groups.The effect of SIRT1 silencing on the senescence of TPC-1 cells was detected by β-galactosidase staining.The effect of SIRT1 silencing on the apoptosis of TPC-1 cells was detected by Hoechst staining.Finally,the effect of SIRT1 silencing on apoptosis and cycle of TPC-1 cells was detected by flow cytometry.Each experiment was repeated 3 times.The data were analyzed statistically.Results 1.The SIRT1 m RNA expression of SIRT1 si RNA-transfected TPC-1 cells was lower than that of the control group.Among them,the SISI1Hs01₀0153667sequence with the concentration of 100 nmol/L had the strongest interference effect（P<0.05）.SIRT1 protein also showed low expression.2.CCK8 gene sensitivity test showed that the cell proliferation rate of SIRT1 si RNA group was significantly lower than that of blank control group and negative control group in day1,day2 and day3（P<0.05）,and the proliferation of transfected cells was significantly inhibited（P< 0.05）;β-galactosidase staining showed that the proportion of senescent cells in the experimental group was significantly higher than that in the blank control group and the negative control group（P<0.05）;Hoechst staining method found that the proportion of apoptotic cells in the experimental group was significantly increased（0.09±0.01）（P<0.05）;The percentage of apoptotic cells in the experimental group was significantly increased by flow cytometry（65.22%±0.41%,P<0.05）;G1 arrest was observed in cells in the experimental group by flow cytometry（67.99%±0.87%,P<0.05）.Conclusion SIRT1 expression in TPC-1 can be successfully interfered by the SIRT1 si RNA named sequence SASI_Hs01₀0153667.The low expression of SIRT1 in human thyroid papillary carcinoma cell line TPC-1 can inhibit cell proliferation,block cell cycle,and induce cell senescence and apoptosis.It is suggested that SIRT1 plays a role as a tumor-promoting factor in the biological function of thyroid papillary carcinoma.Through this target,a breakthrough may be made in the diagnosis and treatment of papillary thyroid carcinoma.