Mattern J, Efferth T, Volm M
German Cancer Research Center, Institute of Experimental Pathology, Heidelberg.
Radiat Res. 1991 Sep;127(3):335-8.
In vivo exposure of a human epidermoid lung carcinoma xenograft to seven irradiation treatments of 10 Gy in consecutive passages resulted in expression of resistance to vincristine. This about threefold drug resistance was detectable with a single dose of 1 mg/kg vincristine. Characterization of the radiation-pretreated subline showed that overexpression of P-glycoprotein, as determined by immunofluorescence and Mabs C219 and 265/F4, occurred in this tumor. After six X-ray fractions, only single positive cells were observed, whereas seven fractions produced an intense immunofluorescent reaction with both antibodies. Southern blot analyses indicated that no gene amplification had occurred. This result shows that irradiation can influence expression of P-glycoprotein and in this way influences drug resistance.
在连续传代过程中，对人肺表皮样癌异种移植物进行七次10 Gy的体内照射治疗后，导致其对长春新碱产生抗性。用1 mg/kg单剂量长春新碱即可检测到约三倍的耐药性。对经辐射预处理的亚系进行表征表明，通过免疫荧光以及单克隆抗体C219和265/F4测定，该肿瘤中P-糖蛋白出现过表达。经过六次X射线分次照射后，仅观察到单个阳性细胞，而七次分次照射则产生了两种抗体的强烈免疫荧光反应。Southern印迹分析表明未发生基因扩增。该结果表明照射可影响P-糖蛋白的表达，进而影响耐药性。
