Expression Of SIRT6 Protein In Colon Cancer And Its Effect On The Biological Behavior Of Colon Cancer Cell

ObjectiveTo explore the relationship between the expression of NAD-Dependent Protein Deacetylase Sirtuin-6(SIRT6)protein in colon cancer tissues and the clinicopathological parameters of colon cancer patients,and to elucidate the relationship between SIRT6 protein and the development of colon cancer.The expression of SIRT6 protein in colon cancer HCT116 and RKO cell lines was regulated by plasmid transfection technology,and the effect of SIRT6 protein expression on the biological behavior of colon cancer cells was explored.The purpose of this study was to clarify the role of SIRT6 protein in the development of colon cancer to provide a new method for the treatment of colon cancer.Method1.Select colon cancer and carcinoma of 100 colon cancer patients who had not undergone radiotherapy and chemotherapy before operation.The expression of SIRT6 protein in colon cancer tissues and paracancerous tissues was detected by tissue microarray technique and immunohistochemical SP method.The rank sum test was used to analyze the relationship between the expression of SIRT6 protein and various clinical parameters.Kaplan-Meier,single factor and multivariate survival analysis were used to analyze the relationship between clinicopathological parameters and prognosis in patients with colon cancer.2.The expression level of SIRT6 protein in RKO,HT-29,SW620,COLO205 and HCT116 colon cancer cells was detected by Western-blot.The highest expression of RKO cells and protein expression of the lowest HCT116 cells were selected.SIRT6 protein was overexpressed by transient transfection of the exogenous SIRT6 plasmid into the HCT116 colon cancer cell line;SIRT6 was silenced by transfection of Small interfering RNA(si-SIRT6)into the RKO colon cancer cell line.The SIRT6 protein overexpression and silencing cell model were successfully constructed by m RNA and protein levels by q PT-PCR and Western blot.3.CCK-8 method was used to detect cell viability;plate cloning assay was used to detect cell proliferation;flow cytometry was used to detect apoptosis to study the effect of colon cancer cells overexpressing SIRT6 or knocking out SIRT6 on biological behavior.Result1.SIRT6 protein is expressed in both nucleus and cytoplasm,and its expression in adjacent tissues is significantly higher than that in cancerous tissues.Kaplan-Meier survival curves showed that SIRT6 protein was highly expressed in the nucleus,young age,low TNM stage,and patients with low T,N,and M stages had a better prognosis.Univariate and multivariate analysis showed that the age was small,the T and N stages were low,and the SIRT6 protein was highly expressed in the nucleus.The prognosis of colon cancer patients was significantly better and may be an independent prognostic factor.2.The results of q RT-PCR and Western blot showed that the expression of SIRT6 in HCT-116 cells transfected with plasmid was significantly increased at RNA and protein levels compared with the control group(transfected blank plasmid)and the blank group;the expression of RKO in colon cancer cells transfected with si-SIRT6 was down-regulated,compared with the control group(transfected NC-si RNA)and blank group,the expression of SIRT6 at RNA and protein levels was both.The cell model was successfully constructed for subsequent experiments.3.Overexpression of SIRT6 reduces the cell viability and proliferation ability of colon cancer cells,and the number of apoptotic cells increases.This indicates that overexpression of SIRT6 inhibits the growth of colon cancer cells and promotes apoptosis of colon cancer cells.After knocking down SIRT6,cell viability and proliferation ability were increased,and apoptotic cells were decreased.It is indicated that knocking down SIRT6 promotes the growth of colon cancer cells and inhibits the apoptosis of colon cancer cells.ConclusionsThe expression of SIRT6 protein in colon cancer tissues is significantly lower than that in adjacent tissues.Colon cancer patients with high expression of SIRT6 protein in the nucleus have a better prognosis,and this protein may be an independent prognostic factor for colon cancer.Overexpression of SIRT6 can inhibit the growth of colon cancer cells and promote the apoptosis of colon cancer cells.Knockdown of SIRT6 promotes colon cancer cell growth,inhibits apoptosis of colon cancer cells,and may acts as a biomarker for colon cancer.