紫杉醇和顺铂对EGFR野生型与突变型肺腺癌细胞的杀伤作用比较及其分子机制

目的 探讨化疗相关基因表达水平与EGFR突变状态的关系及其对化疗疗效的影响。方法 采用MTT法分别检测紫杉醇、顺铂对A549与HCC827细胞的24 h半数抑制浓度（IC50）；比较紫杉醇、顺铂单独及联合作用于A549与HCC827细胞杀伤作用的差异；荧光定量PCR法检测紫杉醇、顺铂作用前后A549与HCC827细胞化疗相关基因（BRCA1、ERCC1、TUBB3）的表达水平。结果 紫杉醇对A549与HCC827细胞24 h的IC50分别为100和70 μg/ml，顺铂对两种细胞的IC50分别为40和50 μg/ml。单独作用时，紫杉醇对HCC827细胞的杀伤作用明显高于A549细胞（P<0.05）；顺铂对A549细胞的杀伤作用明显高于HCC827细胞（P<0.05）；紫杉醇和顺铂联合作用对A549和HCC827细胞的杀伤作用差异无统计学意义（P>0.05），且均表现为单纯相加作用（Q=1.03, 1.06）。HCC827细胞中BRCA1基因表达明显高于A549细胞（P<0.05）；顺铂作用于A549细胞后，其ERCC1基因表达明显升高（P<0.05）。结论 紫杉醇、顺铂单独作用对EGFR野生型与突变型肺腺癌细胞杀伤作用有明显差异，而两者联合无明显差异，可能与BRCA1基因的表达有关；EGFR野生型比突变型肺腺癌细胞更容易对顺铂出现耐药。

Killing Effect of Paclitaxel and Cisplatin on EGFR-wild and Mutant Lung Adenocarcinoma Cells and Related Molecular Mechanism

Objective To investigate the relationship between the expression of chemotherapy-related genes and epidermal growth factor receptor (EGFR) mutation status, and their impact on chemotherapy response. Methods The IC50 of paclitaxel and cisplatin against A549 and HCC827 cells were measured by MTT assay. The cytotoxicities of paclitaxel, cisplatin and their combination against A549 and HCC827 cells were measured and compared. The expression of chemotherapy-related genes, BRCA1, ERCC1 and TUBB3, were detected by fluorescent quantitative PCR before and after paclitaxel and cisplatin treatment. Results The IC50 of paclitaxel against A549 and HCC827 cells were 100 and 70μg/ml respectively while those of cisplatin were 40 and 50μg/ml, respectively. The cytotoxicity of paclitaxel was stronger against HCC827 cells than A549 cells (P<0.05), while the cytotoxicity of cisplatin was higher against A549 cells than HCC827 cells (P<0.05). The cytotoxicities of the combination were not significantly different against A549 and HCC827 cells (P>0.05) and their combination action showed additive effect (Q=1.03, 1.08). BRCA1 expression in HCC827 cells was significantly higher than that in A549 cells (P<0.05). ERCC1 was up-expressed after treated with cisplatin (P<0.05). Conclusion The killing effect of paclitaxel and cisplatin on EGFR-wild and mutant lung adenocarcinoma cells are significantly different, while the combination are not, which may be related with the expression of BRCA1. EGFR-wild lung adenocarcinoma cells are much easier to appear cisplatin-resistance than mutant phenotype.