摘要
目的 探讨CD44 +/CD24+宫颈癌细胞的放射抗拒性机制.方法 体外培养人宫颈鳞癌(Siha)细胞,6MVX射线给予8、16、30 Gy照射,流式细胞仪分选出CD44 +/CD24+细胞.采用克隆形成实验拟合细胞存活曲线,比较细胞的放射敏感性;Hochest 33258荧光染色和透射电镜观察细胞形态变化;流式细胞术(FCM)分析细胞凋亡率;凝胶电泳观察凋亡细胞的DNA条带;反转录-聚合酶链反应(RT-PCR)法检测细胞凋亡相关基因mRNA的表达.结果 随着剂量的增加,CD44 +/CD24+宫颈癌细胞比例逐渐增加;CD44 +/CD24+细胞放射敏感性下降(t=93.99 ~400.45,P<0.05);CD44 +/CD24+细胞中bcl-2、survivin、Oct4基因表达水平较亲代Siha细胞升高(t=221.35、941.65、82.27,P<0.01);Hochest 33258、透射电镜、DNA片段凝胶电泳及流式细胞定量研究显示,Siha细胞出现明显细胞凋亡改变,而Siha CD44 +/CD24+细胞则未出现.结论 CD44+/CD24+宫颈癌细胞抵抗放疗的机制是抗拒射线诱导的细胞凋亡.
Objective To explore whether CD44 +/CD24 + expressing cervical cancer cells are resistant to X-ray irradiation and investigate the underlying mechanism.Methods Cervical cancer cell line (Siha) was cultured in vitro and the CD44 +/CD24 + expressing cells were sorted with a flow cytometer.The cells were irradiated with 8,16 and 30 Gy of 6 MV X-rays.Colony formation test was used to evaluate the radiosensitivity of CD44 +/CD24 + expressing cervical cancer cells.Cell morphology was observed by electronmicroscopy,cell apoptosis was analyzed with a flow cytometer and also verified with a DNA "ladder" assay.Gene expression was determined by RT-PCR.Results After radiation,the ratio of CD44 +/CD24 + cells significantly increased.Compared to Siha cells,the radiosensitivity of CD44 +/ CD24 + cells decreased (t =93.99-400.45,P 〈0.05),and the expressions of bcl-2,survivin and Oct4 mRNA increased in CD44 +/CD24 + cells (t =221.35,941.65,82.27,P 〈0.01).Both apoptotic body and specific DNA "ladder" pattern were observed in cells but not in the CD44 +/CD24 + Sihacells which had no obvious morphological changes of apoptosis.Conclusions The CD44 +/CD24 + expressing cervical cancer cells are resistant to X-rays due to expression of anti-apoptosis factors.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2015年第9期647-651,共5页
Chinese Journal of Radiological Medicine and Protection
基金
河北省科技支撑计划项目,河北省杰出青年科学基金
关键词
宫颈癌
肿瘤干细胞
细胞凋亡
放射抗性
Cervical cancer
Cancer stem cells
Apoptosis
Radioresistance