生存素表达与肺癌多药耐药株H460/cDDP化疗敏感性的关系

目的探讨生存素（survivin）与人肺癌多药耐药株H460／cDDP获得性耐药的关系。方法采用RT-PCR、Western印迹法检测耐药株H460／cDDP与敏感株H460的生存素表达;用针对生存素的小干扰RNA（siRNA）经脂质体介导转染入耐药株H460／cDDP,抑制生存素表达;用四甲基偶氮唑盐法（MTT）检测顺铂（DDP）、紫杉醇（Taxol）对耐药株H460／cDDP的细胞毒作用。结果耐药株H460／cDDP的生存素mRNA和蛋白质表达均高于敏感株H460。生存素siRNA转染耐药株H460／cDDP后72h,生存素蛋白质的抑制率为92、3％。耐药株H460／cDDP和敏感株H460对DDP的Ic50分别为（6.3±0．6）mg／L、（0.8±0．1）mg／L,对Taxol的Ic50分别为（12．7±1．2）mg／L、（1．5±0．3）mg／L;生存素siRNA作用后,H460／cDDP对DDP、Taxol的IC50分别为（4．0±0.9）mg／L（P=0．002）、（8．1±1．7）mg／L（P=0．003）。结论生存素高表达与耐药株H460／cDDP的获得性耐药有关,生存素有可能成为逆转肺癌耐药性的有效靶点。

Relationship between survivin expression and chemosensitivity of human lung cancer cells

OBJECTIVE: To investigate the relationship between survivin expression and the chemosensitivity in multiple drug resistant human lung cancer cell line METHODS: Human lung cancer cells of the parental cell line H460 and multiple drug resistant cell line H460/cDDP were cultured respectively. RT-PCR and Western blotting were used to detect the mRNA and protein expression of survivin. siRNA targeting survivin was transfected into H460/cDDP cells by lipidosome approach. The expression change of survivin protein after transfection was examined by Western blotting. Cisplatine (DDP) and paclitaxel of different concentrations were added into the culture fluid of the H460/cDDP cells respectively. Methylthiazolyl tetrazolium (MTT) assay was used to calculate the IC(50) value so as to detect the cytotoxicity of cisplatine and paclitaxel to the cells. RESULTS: The mRNA expression and protein expression of survivin in the H460/cDDP cells were both significantly higher than those in the H460 cells. 24 h, 48 h, and 72 h after transfection of the survivin siRNA the survivin protein expression levels of the H460/cDDP were decreased by 67.0%, 76.2%, and 92.3% respectively. MTT assay showed that the cisplatine IC(50) levels of the H460/cDDP and H460 cells were 6.3 +/- 0.6 mg/L and 0.8 +/- 0.1 mg/L respectively, and the paclitaxel IC(50) levels were 12.7 +/- 1.2 mg/L and 1.5 +/- 0.3 mg/L respectively. 48 h after the transfection of survivin siRNA, the cisplatine and paclitaxel IC(50) levels of the H460/cDDP cells were decreased to 4.0 +/- 0.9 mg/L (P = 0.002) and 8.1 +/- 1.7 mg/L (P = 0.003) respectively. CONCLUSION: The survivin expression of the resistant cell line H460/cDDP was up-regulated compared with that of the parental cell line H460. Survivin siRNA sensitized the H460/cDDP cells to both cisplatine and paclitaxel. Survivin participates in the multiple drug resistance mechanism of human lung cancer cells.