宫颈癌细胞株和正常间质细胞株受X线照射后的辐射效应

目的用宫颈癌、正常血管内皮和正常成纤维细胞株体外模拟宫颈癌实质和间质组织,研究其受到不同剂量放射线照射后的辐射效应。方法采用宫颈腺癌细胞株HeLa,宫颈鳞癌细胞株SiHa、C33A、Caski,人脐静脉内皮细胞株ECV304,及小鼠成纤维细胞株NIH/3T3细胞,分别用6MV的X线（300cGy/min）照射6和10Gy,24和48h后收集细胞,行PI染色,流式细胞术检测凋亡率和细胞周期变化。结果细胞株受到照射后,C33A凋亡率最高,而SiHa凋亡率最低,其余细胞株（包括ECV304与NIH/3T3细胞）均介于两者之间;各宫颈癌细胞株及NIH/3T3照射10Gy后48h的凋亡率较6Gy稍高（P〉0.05）,而ECV304照射10Gy后48h的凋亡率（13.04%±1.08%）比照射6Gy（6.51%±0.61%）明显升高（P=0.001）;各细胞株受到不同剂量照射后,均表现出明显的G2/M期阻滞,且阻滞细胞百分比随照射剂量增加而增加;受到照射后一般在24-48hG2/M期阻滞细胞百分比最高。结论高剂量照射可以提高血管内皮细胞的凋亡率,并导致剂量依赖性的G2/M期阻滞,为预测宫颈癌的高剂量放疗提供理论依据。

Response of cervical carcinoma and normal interstitial cell lines after X-ray irradiation

Objective To study the response of cervical carcinoma,normal vascular endothelial and fibroblast cell lines simulated as cervical carcinoma tissue after different doses of X-ray irradiation. Methods Human cervical adenocarcinoma cell line HeLa, human cervical squamous carcinoma cell line SiHa, C33A and Caski, human umbilical vein endothelial cell line ECV304 and mouse fibroblast cell line NIH/3T3 were irradiated with 6 MV X-ray at the doses of 6 Gy and 10 Gy. Apoptotic rate and cell cycle of these cells were analyzed by flow cytometry 24 h and 48 h after irradiation. Results Among the cell lines, the apoptotic rate of C33A was the highest, and the SiHa cell line was most resistant to X-ray, while the apoptotic rates of the rest were between C33A and SiHa cell lines after 6 Gy and 10 Gy irradiation. The apoptotic rate of ECV304 after irradiation with 10 Gy (13.04%±1.08%) was higher than that of 6 Gy (6.51%±0.61%,P=0.001). Six cell lines were all blocked at G₂/M phase after irradiation, the percentages of G₂/M phase increased with the augment of irradiation doses and arrived at the maximum at 24-48 h after irradiation. Conclusion High dose irradiation could enhance the apoptotic rate of vascular endothelial cell and increase the cell percentage of G₂/M phase in all cell lines, which provided the references for radiotherapy of cervical carcinoma at high dose of radiation.