Some characteristics of doxoru-bicin-resistant CHO cell line (RC1) were stud-ied by means of cell biological methods and SDS-PAGE electrophoresis. The resistance factor was 16.5-fold, and RC1 revealed cross-resistances to colchicine, actinomycin and har-ringtonine. By indirect immunofluorescence assay, P-glycoprotein was not detected. Compared with CHO, the doxorubicin (DoK) uptake and accumulation of RC1 dlecreased, but the membrane fluidity of RC1 increased. The reduction in drug accumulation was corre-lated with increase in membrane fluidity. Dox was mainly distributed in the cell nucleus of CHO, but in both cytoplasm and nucleus of RC1. This suggested that Dox was transport-ed more slowly in RC1 cytoplasmthan in CHO cytoplasm, resulting in less Dox entrance into the cell nucleus of RC1 than into that of CHO. We also found that a 30-40 kDa nuclear pro tein which was expressed normally in CHO disappeared in RC1.%用细胞生物学和SDS-PAGE电泳方法,研究抗阿霉素(Dox)CHO细胞系(RC1)的特性.用间接免疫荧光法,未测到RC1超表达P-糖蛋白.RC1降低Dox的摄入,增加膜的流动性.Dox在CHO中主要分布在细胞核,在RC1中则分布在细胞质和细胞核.RC1中有一种分子质量为30-40 kDa的核蛋白的表达被抑制,而在敏感CHO中其表达正常.
展开▼
