不同剂量电离辐射对大肠癌细胞株HCT-8的多柔比星敏感性的研究

目的研究不同剂量电离辐射作用后多柔比星（阿霉素）对大肠癌多药耐药细胞株HCT-8细胞毒活性的影响,进一步探讨逆转大肠癌多药耐药性的方法.方法体外培养大肠癌细胞株HCT-8,以400 ng/ml阿霉素作为HCT-8细胞耐药模型刺激浓度制备细胞耐药模型.实验模型分为5组：假照射组;大剂量组（2 Gy）;0.05 Gy＋2 Gy组;0.1 Gy＋2 Gy组;0.2 Gy＋2 Gy组.采用MTT法测定给予阿霉素后大肠癌多药耐药细胞株HCT-8的存活率.结果与假照射组相比,2 Gy大剂量照射组及0.2 Gy＋2 Gy组照射后HCT-8细胞存活率明显降低（P＜0.05）,先给予低剂量照射（0.05 Gy,0.1 Gy）后,再给予大剂量照射,HCT-8细胞存活率降低更明显（P＜0.01）.与单纯2 Gy大剂量照射组比较,0.1 Gy＋2 Gy组HCT-8细胞存活率明显降低（P＜0.05）.结论先给予低剂量照射（0.1 Gy）后,再给予大剂量照射,可提高大肠癌多药耐药细胞株HCT-8对阿霉素的敏感性.

Sensitivity of ADM in colorectal carcinoma cells after different dose of ionizing radiation

Objective To investigate the sensitivity of adriamycin(ADM) in cytotoxic activity of resistant colorectal carcinoma cells after ionizing radiation,and to explore the methods of deteriorating resistent colorectal carcinoma cells.Methods Colorectal carcinoma HCT-8 cells cultured in external were preparated as resistant cell model with 400 ng/ml ADM,test model was divided into five groups:false radiation group,big dose group(2 Gy),0.05 Gy+2 Gy group,0.1 Gy+2 Gy group and 0.2 Gy+2 Gy group.MTT assay was used to examine the survivial rate of resistance colorectal carcinoma cells after ADM.Results The survivial rate of resistance HCT-8 cells with 2 Gy and 0.2 Gy+2 Gy X-ray decreased significantly than that of control group(P<0.05).Following the pretreatment with low doses of X-ray(0.05 Gy,0.1 Gy),HCT-8 cells were irradiated by high doses,the survivial rate of the resistance HCT-8 cells decreased significantly(P<0.01).The survivial rate of the resistance HCT-8 cells with 0.1 Gy+2 Gy decreased significantly than 2 Gy X-ray irradiated group(P<0.05).Conclusion Following the pretreatment with low doses of X-ray(0.1 Gy),HCT-8 cells are irradiated by high doses and the sensitivity of the resistance HCT-8 cells can be improved.