^(252)锎中子放疗对宫颈癌细胞凋亡及bcl-2、bax的影响

Effects of ^(252)Cf neutron radiation on apoptosis and bcl2, bax of uterine cervical carcinoma cells

目的探讨中子放疗前后宫颈癌细胞凋亡、凋亡相关基因bcl-2、bax表达的变化及意义。方法应用TUNEL法、免疫组化检测宫颈鳞癌放疗前后的细胞凋亡、凋亡相关基因bcl-2、bax表达变化。结果20例患者宫颈癌细胞凋亡阳性率和凋亡指数(AI)分别由放疗前的35%和(4.22±4.14)%增加至放疗后的85%和(34.64±24.36)%,差异显著(P<0.01)。放疗前后bcl-2表达无明显变化(P>0.05),且与凋亡无明显相关(P>0.05)。bax表达阳性率和平均标记指数分别由放疗前的25%和(8.35±3.06)%增加至放疗后的80%和(16.43±6.05)%,差异显著(P<0.01),且放疗后与凋亡呈正相关(r=0.8520,P<0.01)。结论252锎中子射线诱导了肿瘤细胞的凋亡,可能是其治疗作用的重要机制之一;bax表达是252锎中子射线诱导细胞凋亡的途径之一,其机制可能与bcl-2/bax间的平衡改变有关。

Objective To study the apoptosis and the expression of apoptosis-related gene bcl-2 and bax in the cervical carcinoma cells before and after ^252Cf neutron brachytherapy and to determine the mechanism of ^252Cf neutron brachytherapy and its clinical significance. Methods Twenty cases of cervical carcinoma without surgery and routine radiotherapy were enrolled, aged from 26 to 53 years with an average of 37.85. The apoptosis and the expressions of bcl-2, bax gene were detected before and after 252 Cf neutron brachytherapy by TUNEL and immunohistochemical methods. Results The mean apoptosis index （AI） and the positivity rate of apoptosis increased from （4.22±4.14）% and 35% before radiotherapy to （34.64±24.36）% and 85% after radiotherapy （ both P 〈0.01 ）. The positivity rates of bax and the mean labeling indexes increased from 25% and （8.35±3.06）% before radiotherapy to 80% and （16.43 ±6.05）% after radiotherapy （both P〈0.01）. A positive correlation was found between the expression of bax and apoptosis after radiotherapy （ r = 0. 852 0, P 〈 0.01 ）,but no relation between bcl-2 and apoptosis. Conclusion Inducing tumor cells apoptotic may be the important mechanism of ^252Cf neutron brachytherapy. The balance between bax and bcl-2 changes modulates the apoptosis.