靶向抑制c-Myc表达与吉西他滨联合应用增强膀胱肿瘤细胞的化疗敏感性

The combined application of targeted c-Myc expression inhibition and gemcitabine to enhance the chemosensitivity to bladder tumor cells

目的观察靶向抑制c-Myc并与吉西他滨联合应用对膀胱肿瘤细胞化疗敏感性的影响。方法免疫组化检测膀胱肿瘤组织及癌旁组织c-Myc表达,设计合成针对c-Myc基因mRNA的小干扰RNA si-c-Myc,使用阳离子聚合物转染试剂将其导入人膀胱移行细胞癌SW780细胞并与吉西他滨联合培养,流式细胞术检测SW780细胞凋亡变化,Western blot检测c-Myc及细胞凋亡蛋白caspase 9 pro、caspase 3 pro、Bcl-2和Bax的表达水平。结果膀胱肿瘤组织内c-Myc表达明显高于癌旁组织(P<0.01),si-c-Myc与吉西他滨联合应用,可显著提高膀胱肿瘤细胞凋亡率(P<0.01),同时caspase 9 pro、caspase 3 pro和Bcl-2的表达明显下调(P<0.05),而Bax蛋白表达则明显上调(P<0.05)。结论靶向抑制c-Myc表达与吉西他滨联合应用可有效增强膀胱肿瘤细胞对化疗的敏感性,可作为膀胱肿瘤细胞靶向治疗的候选基因。

Objective To observe the effect of targeted c-Myc expression inhibition combined with gemcitabine on the chemosensitivity of bladder tumor cells.Methods The expression of c-Myc in bladder tumor tissues and adjacent tissues was detected by immunohistochemistry.Small-interfering RNA si-c-Myc for c-Myc mRNA was designed and synthesized.It was transfected into human bladder transitional cell carcinoma SW780 cells using cationic polymer transfection reagent,which were co-cultured with gemcitabine.The changes in the apoptosis of SW780 cells were detected by flow cytometry.The expressions of c-Myc as well as the related apoptosis proteins including caspase 9 pro,caspase 3 pro,Bcl-2 and Bax were determined by western blot assay.Results The expression of c-Myc in bladder tumor tissues was significantly higher than that in adjacent tissues.The combination of si-c-Myc and gemcitabine significantly increased the apoptosis rate of bladder tumor cells.Additionally,the expression of caspase 9 pro,caspase 3 pro and Bcl-2 proteins was significantly down-regulated,while the expression of Bax protein was significantly up-regulated.Conclusion The combined application of targeted c-Myc expression inhibition and gemcitabine works effectively in enhancing the chemosensitivity to bladder tumor cells.It could be used as candidate gene for targeted treatment of bladder tumor.