SIRT6 Inhibits Metastasis Via Suppressing SNAIL Transcription In Nasopharyngeal Carcinoma Cells

Objective1.To explore the expression of SIRT6 in nasopharyngeal carcinoma cells.2.To observe the effect of SIRT6 on the migration ability of nasopharyngeal carcinoma cells.3.To explore the mechanism of SIRT6 on the migration ability of nasopharyngeal carcinoma cells.Methods1.We used q PCR and Western Blot to detect the expression of SIRT6 in 5-8F and 6-10 B nasopharyngeal carcinoma cell lines.2.Overexpression of SIRT6 in 5-8F cell lines and downregulated the expression of SIRT6 in 6-10 B cell lines by plasmid transfection to construct a nasopharyngeal carcinoma cell model that regulates SIRT6 expression.3.The effect of SIRT6 on the migration ability of nasopharyngeal carcinoma cells was detected by wound healing assay and trans-well test.4.The mechanism of the effect of SIRT6 on the migration ability of nasopharyngeal carcinoma was detected by co-IP and Ch IP experiments.Results1.We first tested the effects of increased SIRT6 expression in 5-8F cells.Indeed,the migratory and invasive abilities of 5-8F-SIRT6 cells were significantly impaired,as demonstrated by delayed wound closure in a scratch wound healing assay,and decreased invasion rate in a Matrigel invasion assay as well as reduced migration rate in a trans-well migration assay.Next,we investigated whether downregulating SIRT6 expression in 6-10 B cells could promote metastasis or not.The scratch wound healing assay showed that reduced SIRT6 expression markedly enhanced wound closure in6-10B-sh SIRT6 cells compared with 6-10B-sh GFP cells.In addition,Matrigel invasion assay and trans-well migration assay revealed that inhibition of SIRT6 expression significantly upregulated the metastatic capacity of 6-10 B cells.2.The highly expression of SNAIL is related to the high metastasis potential of colorectal cancer,liver cancer,lung cancer and nasopharyngeal cancer.Through cell transfection,we knock down the expression of SNAIL in 6-10B-sh GFP and6-10B-sh SIRT6 cell lines.The result of trans-well assay showed that the invasion and migration ability of 6-10 B cells were significantly reduced in 6-10B-sh GFP and6-10B-sh SIRT6 cell lines after knocked down SNAIL,suggesting that SIRT6 may play a role through SNAIL in nasopharyngeal carcinoma cell lines.Meanwhile,we also performed co-IP to detect the interaction between SIRT6 and SNAIL in nasopharyngeal carcinoma cell lines.In addition,we found that SIRT6 functions as a histone deacetylase to suppress SNAIL expression through deacetylating histone H3K9 and H3K56 at the promoter of SNAIL gene.Conclusions1.SIRT6 is expressed in both 5-8F and 6-10 B nasopharyngeal carcinoma cell lines,and the expression in the 6-10 B cell line is significantly higher than in the 5-8F cell line.2.The expression of SIRT6 is negatively correlated with the migration ability of nasopharyngeal carcinoma cells.High expression of SIRT6 can inhibit the migration of nasopharyngeal carcinoma cell lines,while reducing SIRT6 can promote the migration of nasopharyngeal carcinoma cell lines.3.SIRT6 can interact with P65 to deacetylate H3K9 and H3K56 in the promoter region of SNAIL,thereby inhibiting the expression of SNAIL.