SIRT1基因沉默对鼻咽癌CNE-1细胞放射敏感性的影响

Effect of SIRT1 gene silencing on radiosensitivity of nasopharyngeal carcinoma CNE-1 cells

目的探究SIRT1基因沉默对人鼻咽癌细胞CNE-1放射敏感性的影响,为鼻咽癌临床治疗提供新的思路。方法通过Western blot检测鼻咽癌组织及鼻咽癌细胞中SIRT1蛋白的表达情况。通过脂质体转染SIRT1 siRNA至CNE-1细胞;利用CCK-8法和流式细胞术检测不同剂量(0、2、4、6、8 Gy)的X射线放射处理对CNE-1细胞增殖和凋亡的影响。采用Western blot检测SIRT1沉默后,X射线放射对凋亡相关蛋白Bcl-2、Bax和Cleaved-Caspase3表达的影响。结果鼻咽癌组织和鼻咽癌细胞中SIRT1蛋白的表达量高于癌旁组织及鼻咽正常上皮细胞NP69中的表达量(P<0.05)。靶向SIRT1基因的siRNA转染能特异性的抑制细胞中SIRT1的表达(P<0.05);4、6、8 Gy剂量的X射线放射处理能降低SIRT1 siRNA组CNE-1细胞增殖率,并增加凋亡率(P<0.01)。用X射线照射SIRT1基因沉默的CNE-1细胞,能增加促凋亡蛋白Bax和Cleaved-Caspase3表达量,降低抑凋亡蛋白Bcl-2的表达量(P<0.05)。结论 SIRT1基因沉默可能通过抑制CNE-1细胞增殖,并诱导细胞发生凋亡,从而增强CNE-1细胞对放疗的敏感性,SIRT1基因有望成为鼻咽癌治疗的新靶点。

Objective To investigate the effect of silencing SIRT1 gene by RNA interference on the radiosensitivity of human nasopharyngeal carcinoma cell line CNE-1,and to provide a new idea for clinical treatment of human nasopharyngeal carcinoma(PCN).Methods SIRT1 protein in NP69 and CNE-1 cells was detected by Western blot assay.The SIRT1-siRNA interference sequence was transfected into CNE-1 cells.The ability of cell proliferation was evaluated by CCK-8 assay.The cell apoptosis rate was detected by flow cytometry assay.The protein levels of Bcl-2,Bax,and Cleaved-Caspase3 were tested by Western blot assay.Results The results showed that the expression of SIRT1 protein in nasopharyngeal carcinoma tissues and cells was significantly higher than that of para-carcinoma tissues and NP69 cells(P<0.05).The expression levels of SIRT1 gene and SIRT1 protein in the cells of the transfection groups were significantly lower than that in the control group(P<0.05).The results showed after X-ray radiation of 4,6 and 8 Gy on CNE-1 cells,the ability of cell proliferation in the SIRT1 siRNA groups was obviously lower than that in the control group(P<0.01),and the cell apoptosis rate in the SIRT1 silence groups was significantly higher than that in the control group(P<0.01).Meanwhile,compared with the control group,the protein levels of Bax and Cleaved-Caspase3 significantly reduced,Bcl-2 expression significantly increased in SIRT1 siRNA group(P<0.05).Conclusion Silence of SIRT1 gene may enhance the sensitivity of CNE-1 cells to radiotherapy by inhibiting the proliferation and inducing apoptosis of CNE-1 cells,and SIRT1 gene may be a potential target for the treatment of nasopharyngeal carcinoma cancer.