化疗药物增强重组可溶性TRAIL抗肿瘤作用

目的探讨化疗药物对重组可溶性TRAIL(rsTRAIL)抗肿瘤作用的影响及其分子机制.方法 13株不同肿瘤细胞经rsTRAIL处理后,采用MTS-PMS染色法和流式细胞仪技术测定细胞凋亡率,观察肿瘤细胞对rsTRAIL的敏感性;化疗药物与rsTRAIL联合作用于敏感性不同的肿瘤细胞检测细胞敏感性的变化;免疫印迹技术分析TRAIL受体DR5蛋白表达.结果 13株肿瘤细胞中约46.2%(6/13)的细胞株对rsTRAIL敏感;化疗药物CHX、CP和8-CA可显著提高肿瘤细胞株对rsTRAIL细胞毒作用的敏感性;8-CA和TRAIL联合作用可上调DR5的蛋白表达.结论化疗药物CHX、CP和8-CA可增强rsTRAIL的抗肿瘤作用.

Chemotherapeutic drugs enhanced rsTRAIL tumoricidal activity

OBJECTIVE: To explore the role and mechanisms of chemotherapeutic drugs in TRAIL induced cell death. METHODS: Tumoricidal activities of the chemotherapeutic drugs and/or rsTRAIL in 13 strains of tumor cell lines were evaluated by MTS-PMS assay and flow cytometry. DR5 expression in the cells was observed by Western blot. RESULTS: The apoptosis of human promyelocytic leukemia cells HL-60, liver cancer cells BEL-7402, T-acute lymphoblastic leukemia cells Jurkat, and myeloid leukemia cells K562 treated with rsTRAIL at 0.5 microg/ml were 53.20%, 52.20%, 51.54%, 52.70%, and 41.00%, respectively, while that of the embryonal spleen cells 293 was 24.00%. However, the apoptosis percentages of lung cancer cells anti 973, breast cancer cells MCF-7, Chinese hamster ovarian cancer cells COS-7, neuroglialoma cells U251, neuroblastoma cells SH-SY5Y, glioma cells BT-325, rat pheochromocytoma cells PC12, and mouse adrenal epithelial cells NIH3T3 were all less than 10% under the same conditions. The sensitivity of central neuron cells of SH-SY5Y, PC-12, U251, BT3251, and human embryonal spleen cells 293, which were not sensitive to rsTRAIL challenges, increased remarkably after treatment with CHX, CP, and 8-CA at sub-toxic doses plus rsTRAIL at 0.5 microg/ml. The expressions of DR5 were up-regulated and kept pace with the onset of apoptosis in the BEL-7402 liver cancer cells. CONCLUSION: The chemotherapeutic drugs including CHX, CP, and 8-CA at sub-toxic doses can enhance antitumor activity of rsTRAIL.