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目的证明野生型ｐ５３调节肝癌细胞Ｐ－糖蛋白（ｐ－ｇｌｙｃｏｐｒｏｔｅｉｎ，Ｐ－ｇｐ）表达的设想。方法通过采用脂质体介导转染技术，将野生型ｐ５３ ｃＤＮＡ导入一种ｐ５３和Ｒｂ基因缺失的肝癌细胞株Ｈｅｐ３Ｂ。结果经Ｇ４１８筛选获得稳定整合了野生型ｐ５３的克隆（ｗｔ－ｐ５３）和空载体克隆（ｐＮｅｏ）；经ｎｏｒｔｈｅｒｎ和ｗｅｓｔｅｒｎ印迹鉴定， ｗｔ－ｐ５３细胞表达ｐ５３； ｐ２１ｗａｆｌ／ｃｉｐｌ蛋白的升高证实ｗｔ－ｐ５３细胞的ｐ５３有转录活性，并致使Ｐ－ｇｐ表达降低。细胞毒性试验表明：与ｐＮｅｏ细胞相比， ｗｔ－ｐ５３细胞对阿霉素和丝裂霉素化疗敏感。流式细胞仪显示： ｗｔ－ｐ５３细胞的阿霉素荧光量为ｐＮｅｏ细胞的１３倍。结论在肝癌细胞Ｈｅｐ３Ｂ中重建野生型ｐ５３的活性由于降低Ｐ－ｇｐ的表达而对化疗药敏感。
Objective To prove that wild-type p53 regulates the expression of P-glycoprotein (P-gp) in hepatoma cells. Methods The wild-type p53 cDNA was introduced into a hepatoma cell line Hep3B with deletion of p53 and Rb genes by liposome-mediated transfection. Results The clones (wt-p53) and empty vector clones (pNeo) stably integrated with wild-type p53 were obtained by G418 selection. p53 was expressed in wt-p53 cells by northern and western blotting; the increase in p21wafl/cipl protein was confirmed by wt- P53 cells have transcriptional activity and lead to decreased P-gp expression. Cytotoxicity tests showed that wt-p53 cells are sensitive to doxorubicin and mitomycin chemotherapy compared to pNeo cells. Flow cytometry showed that the fluorescence of doxorubicin in wt-p53 cells was 13 times that of pNeo cells. Conclusions The activity of reconstructing wild-type p53 in hepatoma cells Hep3B is sensitive to chemotherapeutic agents due to decreased P-gp expression.