Expression analysis and biological regulation of silencing regulatory protein 6 (SIRT6) in cutaneous squamous cell carcinoma

Abstract Background Cutaneous squamous cell carcinoma (CSCC) is one of the most common types of skin cancer worldwide. Therefore, the identification of biomarkers associated with CSCC progression could aid in the early detection of high-risk squamous cell carcinoma and the development of novel therapeutic strategies. Objective This study aimed to investigate the expression patterns of silent mating type Information Regulation 2 homolog 6 (SIRT6) in CSCC and its clinical significance. Methods The protein expression level of SIRT6 in tissues was detected by immunohistochemistry, and the correlation between SIRT6 expression and clinicopathological parameters in CSCC patients was analyzed. The relative expression of SIRT6 in CSCC cell lineage and tissue specimens was determined by western blotting and PCR. The effect of SIRT6 silencing on cell proliferation was evaluated using cell counting kit 8. Wound healing, transwell method, and flow cytometry were used to investigate the migration, invasion, and cell cycle distribution/apoptosis of CSCC cells after SIRT6 silencing, respectively. Western blot was used to detect the expression of EMT (Epithelial-Mesenchymal Transition), cycle, apoptosis, and other related proteins. Results The high expression of SIRT6 was correlated with the location of cancer tissue and Broder staging in CSCC patients. Knockdown of SIRT6 inhibited the proliferation, migration, invasion and EMT of CSCC cells, and promoted their apoptosis, with cells blocked in G1 phase. Study limitations No animal experiments were conducted to further verify the results. Conclusion Decreased expression of SIRT6 can inhibit the occurrence and development of CSCC.

Expression of SIRT6 protein in colon cancer tissue detected by tissue microarray technique and its clinical significance / 吉林大学学报(医学版)

Objective:To investigate the expression of NAD-dependent protein deacetylase sirtuin-6(SIRT6) protein in the colon cancer tissue and the association between its expression and the clinicopathological parameters of the patients with colon cancer, and to elucidate the effect of the SIRT6 protein in the occurrence and development of colon cancer.Methods:The colon cancer tissue and the paracancerous tissue obtained from 100 patients who did not receive radiotherapy and chemotherapy before operation were selected.The expression levels SIRT6 protein in colon cancer tissue and paracancerous tissue were detected by tissue microarray technique and immunohistochemical SP method. The relationships between the expression of SIRT6 and the clinicopathological parameters of the patents with colon cancer were analyzed with rank sum test. Kaplan-Meier survival curre,univariate analysis and multivariate survival analysis were used to investigate the relationships between the clinicopathological parameters and the prognosis in the patients with colon cancer.Results:The expression levels of SIRT6 in cytoplasm and nucleus in colon cancer tissue were significantly higher than those in paracancerous tissue (Z=-4.603,P=0.000;Z=-7.610,P=0.000).The Kaplan-Meier univariate and multivariate analysis showed that the prognosis of the patients with high expression of SIRT6 in the nucleus was better, and the expression of SIRT6 was identified as the independent prognostic factor of colon cancer(HR=2.345,P=0.003); the patients with younger age, lower T and N stages had higher survival rates (HR=0.394,P=0.004; HR=2.301,P=0.012; HR=2.423,P=0.048);there was no correlation between the high expression of SIRT6 in cytoplasm and the prognosis (HR=1.309,P=0.333) of the patients with colon cancer.Conclusion:SIRT6 protein is highly expressed in the nucleus of colon cancer and it can be used as a good prognostic indicator for colon cancer.