人食管鳞癌紫杉醇耐药细胞株Ec9706/P-1凋亡的变化

Apoptosis in Paclitaxel Resistant Cell Line Ec9706/P-1 of Human Esophageal Carcinoma

目的探讨人食管癌紫杉醇耐药细胞株凋亡的变化。方法以体外诱导的人食管癌紫杉醇耐药细胞株Ec9706/P-1为模型,采用反转录—多聚酶链反应(RT-PCR)检测NF-κB-p65、bcl-2和caspase-3mRNA的表达;应用免疫组织化学方法检测NF-κB-p65、Bcl-2和Caspase-3蛋白的表达;采用吖啶橙荧光染色法检测细胞凋亡变化。结果 RT-PCR法显示NF-κBmRNA和bcl-2mRNA在Ec9706/P-1细胞中表达条带亮度强于Ec9706;caspase-3mRNA在Ec9706/P-1细胞中条带亮度较Ec9706细胞弱。免疫组织化学方法显示NF-κB-p65蛋白和Bcl-2蛋白在Ec9706/P-1细胞中的表达率高于Ec9706细胞,两者比较差异有统计学意义(P<0.05);Caspase-3蛋白在Ec9706/P-1细胞中的表达率低于Ec9706细胞,两者比较差异有统计学意义(P<0.05)。吖啶橙荧光染色法表明Ec9706/P-1细胞的凋亡率低于Ec9706细胞,差异有统计学意义(P<0.05)。结论人食管癌紫杉醇耐药细胞株Ec9706/P-1产生耐药可能与NF-κB-p65、Bcl-2表达水平升高,Caspase-3表达水平降低有关,其逃避凋亡而导致耐药。

Objective To investigate the change of apoptosis in paclitaxel resistant cell line of human esophageal carcinoma Ec9706/P-1.Methods The expression levels of Bcl-2,caspase-3 and NF-κB were detected by semi-quantitive reverse transcription-polymerase chain reaction（RT-PCR） assay.The expressions of Bcl-2 protein,Caspase-3 protein and NF-κB protein were determined by immunohistochemistry.DNA fragments were resolved by agarose gel electrophoresis to detect cell apoptosis.Apoptosis rates and morphology were detected by acridine orange（AO） fluorescent staining.Results The expression levels of bcl-2 and NF-κB in Ec9706/P-1 cells were significantly higher than those in Ec9706 cells （P〈0.05）.The expression level of caspase-3 in Ec9706/P-1 cells was decreased significantly （P〈0.05）,compared with Ec9706 cells.Immunohistochemistry assay showed that positie expression rates of Bcl-2 and NF-κB in Ec9706/P-1 cells were higher than those in Ec9706 cells statistically （P〈0.05）.The positive expression rate of Caspase-3 protein in Ec9706/P-1 cells was significantly lower than that in Ec9706 cells （P〈0.05）.Conclusion The possible mechanisms of acquired resistance of Paclitaxel-resistant human esophageal carcinoma cell line Ec9706/P-1 may be caused by overexpression of Bcl-2 and NF-κB,down-regulation of Caspase-3.Ec9706/P-1 cells escaping from apoptosis may be one of resistant mechanisms.