放疗对宫颈癌细胞系的增殖抑制及抑癌基因p16、MGMT表达的影响

Effects of radiotherapy on proliferation inhibition of cervical cancer cell lines and expression levels of tumor suppressor genes p16 and MGMT

目的研究放疗对宫颈癌细胞系的增殖抑制及抑癌基因p16、O6-甲基鸟嘌呤-DNA转移酶(MGMT)表达的影响。方法培养2种人宫颈癌细胞系Hela、C33A,分为对照组和辐照组,正常培养作对照组(Control),接受X射线辐照为辐照组,辐照剂量为4 Gy;采用噻唑蓝(MTT)法检测细胞增殖,流式细胞仪检测细胞凋亡情况,实时荧光定量-聚合酶链式反应(qRT-PCR)和蛋白印记(Western Blot)检测细胞中凋亡相关蛋白B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关x蛋白(Bax)及抑癌基因p16、MGMT的表达。结果与对照组相比,辐照组宫颈癌Hela、C33A细胞增殖活性、Bcl-2/Bax的表达显著下降,凋亡率、p16、MGMT的表达显著上调(P <0. 05)。结论放疗可通过上调宫颈癌Hela、C33A细胞中p16、MGMT的表达,下调Bcl-2/Bax的表达,抑制细胞增殖,促进其凋亡。

Objective To study the effects of radiotherapy on the proliferation inhibition of cervical cancer cell lines and the expression levels of tumor suppressor genes p16 and O6-methylguanine-DNA transferase(MGMT).Methods Two human cervical cancer cell lines Hela and C33A were cultured and divided into control group and irradiation group.The cell lines with normal culture were used as control group and those with X-ray irradiation were used as irradiation group,and irradiation dose was 4 Gy.Cell proliferation was detected by methyl thiazolyl tetrazolium(MTT)assay,and apoptosis was detected by flow cytometry,and real-time fluorescence quantitative-polymerase chain reaction(qRT-PCR)and Western blot were performed to detect the expression levels of apoptosis-related protein Blymphocytoma-2 gene(Bcl-2),Bcl-2-related x protein(Bax)and tumor suppressor genes p16 and MGMT.Results Compared with control group,the proliferation activity and Bcl-2/Bax expression of Hela and C33A cells in irradiation group were significantly decreased,while the apoptosis rate and expression levels of p16 and MGMT were significantly up-regulated(P<0.05).Conclusion Radiotherapy can inhibit cell proliferation and promote apoptosis by up-regulating the expression levels of p16 and MGMT in Hela and C33A cells and down-regulating the expression level of Bcl-2/Bax.