HBXIP蛋白表达对宫颈癌细胞的增殖能力及放射敏感性的影响

Effects of HBXIP protein expression on the proliferation and radiosensitivity of cervical cancer cells

目的 探讨用siRNA敲降乙肝病毒X蛋白结合蛋白（HBXIP）的表达对宫颈癌ME-180细胞的增殖能力及放射敏感性的影响。方法 根据不同的处理方法，分别按两种分组方式进行分组。（1）把宫颈癌ME-180细胞分为4组：空白对照组、4 Gy γ射线照射组、HBXIP-siRNA转染组以及HBXIP-siRNA＋γ射线照射联合组。采用MTT和克隆形成实验法来检测细胞增殖；采用qRTPCR检测凋亡相关蛋白Bcl-2及Bid的表达；Western blot检测蛋白激酶AKT的磷酸化水平。（2）把宫颈癌ME-180细胞分为3组：空白对照组、HBXIP-siRNA单独处理组、HBXIP-siRNA和AKT共转染组。对3组细胞进行不同剂量的γ射线照射，并采用克隆形成实验方法检测细胞生长。采用Student t-test对数据进行统计学分析，P〈0.05表示差异有统计学意义。结果 MTT实验和克隆形成实验结果显示，与γ射线照射组相比，HBXIP-siRNA转染＋γ射线照射联合组的宫颈癌ME-180细胞增殖率明显降低（t=11.63、12.17，均P〈0.01），并伴随抑凋亡蛋白Bcl-2表达的降低（t=10.88，P〈0.01）和促凋亡蛋白Bid表达的增高（t=9.31，P〈0.01）。γ射线照射明显上调了HBXIP蛋白的表达水平和AKT蛋白的磷酸化水平，而转染HBXIP-siRNA则抑制了γ射线照射导致的AKT磷酸化水平的升高。另外，与HBXIP-siRNA单独处理组相比，HBXIP-siRNA和AKT共转染组中HBXIP-siRNA对宫颈癌ME-180细胞增殖的影响显著降低（t=8.96，P〈0.01）。结论 降低HBXIP蛋白表达可以抑制辐照诱导的AKT磷酸化水平，进而降低宫颈癌ME-180细胞的增殖能力，同时增强其放射敏感性。

Objective To explore the effects of （hepatitis B X-interacting protein） HBXIP downregulation on the proliferation and radiosensitivity of cervical cancer ME-180 cells. Method According to the different treatment methods, cervical cancer ME -180 cells were divided into different groups：（1）The cervical cancer ME -180 cells were divided into 4 groups：control group, 4 Gy γ ray irradiation group, HBXIP-siRNA transfection group and HBXIP-siRNA transfection＋γ ray irradiation group. cervical cancer ME-180 cell proliferation was detected by MTT and clonogenic assays. The expression of Bcl-2 and Bid mRNA was detected by quantitative real-time polymerase chain reaction, and the phosphorylation of AKT protein was measured by Western blot analysis. （2）The cervical cancer ME-180 cells were divided into 3 groups：control group, HBXIP-siRNA transfection group and HBXIP-siRNA＋AKT transfection group. Then the three groups of cells were irradiated with different doses of γ ray, and the cervical cancer ME-180 cell proliferation was detected by clonogenic assay. Statistical significance of the results was determined by SPSS statistical software and analyzed by Student t-test. P〈0.05 were considered statistically significant. Results MTT and clonogenic assays showed that, compared with the cells irradiated alone, the cervical cancer ME-180 cells irradiated in the presence of HBXIP-siRNA had significantly decreased proliferation （t=11.63, 12.17, P〈0.01）. The decreased proliferation was accompanied by a decreased expression of Bcl-2 protein （t=10.88, P〈0.01） and an increased expression of Bid protein （t=9.31, P〈0.01）. The transfection with HBXIP-siRNA inhibited the increased HBXIP protein expression and AKT phosphorylation, which were caused by radiation. The enhanced AKT expression significantly reduced the HBXIP -siRNA inhibition of cervical cancer ME-180 cell proliferation after irradiation as compared with that of the HBXIP-siRNA alone （t=8.96, P〈0.01）. Conclusion HBXIP down -regulation reduced the proliferation and increased the radiosensitivity of cervical cancer ME-180 cells by mediating AKT activation.