重组新城疫病毒rClone30-hDR5联合TRAIL对人肝癌细胞的协同作用及其机制探讨

The synergism and mechanism of action of rClone30-hDR5 in combination with TRAIL on HCC

为研究重组新城疫病毒rClone30-hDR5联合TRAIL蛋白对人肝癌细胞株HepG2的杀伤作用及其机制,首先将pee12.4-hDR5转染HepG2细胞,利用流式细胞仪筛选,建立了细胞表面稳定高效表达DR5的HepG2细胞系。利用MTT法检测TRAIL对该细胞和对照HepG2细胞的抑制率,表明TRAIL对该细胞的抑制率显著高于对照HepG2细胞(P<0.01),证明了克隆的hDR5具有生物学活性;与rClone30-hDR5组和TRAIL组相比,rClone30-hDR5联合TRAIL在体外能更好地抑制HepG2细胞的生长。Annexin V-FITC/PI染色和Quantitative Real-time PCR结果表明,与其他组相比,rClone30-hDR5联合TRAIL显著提高caspase 3和caspase 8的mRNA表达水平并协同诱导细胞凋亡。以1 MOI感染HepG2细胞,流式细胞仪检测证明,与rClone30相比,rClone30-hDR5能显著诱导hDR5的表达上调,从而增加肿瘤细胞对TRAIL的敏感性。综上所述,rClone30-hDR5联合TRAIL在肿瘤治疗方面存在潜在的应用价值。

To investigate the cell-killing effect and its possible mechanism of rClone30-hDR5 in combination with TRAIL on human hepatic carcinoma（HCC） cell line, first of all, recombinant plasmid pee12.4-hDR5 was introduced into HepG2 cells by liposome transfection. After five rounds of screening by flow cytometry, HepG2 cells expressing high levels of DR5 on cell surface were isolated. The cytotoxicity of TRAIL to selected cells was higher than that of TRAIL to HepG2 cells by MTT method（P 0.01）. The result suggested that the cloned hDR5 gene had biological activity. MTT assay showed that, rClone30- hDR5 in combination with TRAIL more efficiently inhibited the tumor growth of HepG2 cells compared to rClone30-hDR5 or TRAIL in vitro. The results of Annexin V-FITC/PI staining and Quantitative Real-time PCR indicated that rClone30-hDR5 in combination with TRAIL significantly increased the mRNA levels of caspase 3 and caspase 8, and induced the apoptosis of tumor cells. HepG2 cells were infected with rClone30-hDR5 or rClone30 at MOI of 1. The expression of hDR5 on tumor surface increased significantly by rClone30-hDR5 compared to that by rClone30, which contributed to the sensitivity to TRAIL. In conclusion, rClone30-hDR5 in combination with TRAIL has potential application value in cancer treatment.