一种新型增殖型腺病毒治疗肝癌的体外研究

目的 评价增殖腺病毒CNHK500对肝癌细胞的治疗效果。方法 利用病毒增殖实验、细胞活力实验(MTT)、蛋白印迹分析来检测增殖病毒CNHK500在端粒酶阳性的肝癌细胞株HepGⅡ、Hep3B、SMMC7721及正常细胞中选择性增殖和溶解细胞的特性。结果 CNHK500感染人肝癌细胞株HepGⅡ、Hep3B、SMMC7721细胞后大量增殖,在感染后96小时增殖倍数分别为52000、396984．9和632911．3倍,同野生型5型腺病毒(wtAd5)类似。然而在正常细胞中,CNHK500的增殖能力较wtAd5大大减弱,感染96小时后仅增殖3．1～100倍,而wtAd5却高达3160～17357倍。MTT实验观察到在肝癌细胞HepGⅡ和Hep3B中,感染后第7天达到半数杀伤的MOI值(IC50)分别为2和0．01,而在正常成纤维细胞BJ细胞中却高达1000。在常氧情况下,用蛋白印迹可在肿瘤细胞中检测到腺病毒ElA蛋白的表达,但在正常细胞却检测不到。EIB蛋白仅在缺氧条件下(0．1％O2)的肿瘤细胞中表达。结论 实验结果表明CNHK500能有效地选择性在肝癌细胞中增殖、复制、杀伤,而在正常细胞中增殖和溶解细胞能力却大大减弱。联合治疗基因,CNHK500可能为肝癌的治疗提供一种新的策略。

A Novel Replication-competent Adenovirus CNHK500 in the Treatment of Heptocellular Carcinoma In Vitro

Objective: To evaluate the therapeutic efficacy of replicative adenovirus CNHK500 in the treatment of hepatocellular carcinoma. Methods: Virus proliferation assay, cell viability assay and Western blot were performed to assess the selective replication and cytolysis of CNHK500 in telomerase positive liver cancer cells Hep3B, HepGII, SMMC7721 and in normal cells. Results: The replicative multiples of CNHK500 in HepGII, Hep3B and SMMC7221 after 96 h of virus proliferation were 52 000, 396 984.9 and 632 911.3 fold respectively, similar to those of wtAd5. However, CNHK500 demonstrated more significant attenuated replicative ability in normal cell lines than wtAd5. CNHK500 replicated only 3.1-100 fold at 96 h, while the wtAd5 still reached 3160-17 357 fold. CNHK500 could cause half of HepGII cells death within 7 days at MOI 2, in Hep3B cell lines the IC50 was as low as MOI 0.01, whereas the IC50 in BJ cell was as high as MOI 1000. CNHK500 E1A protein could only be detected in hepatocellular cancer cells but not in normal cells under normoxia. E1B protein could only be detected under hypoxia condition at a MOI of 1. Conclusion: CNHK500 can efficiently replicate in and kill liver cancer cells as well as wtAd5 do while it is severely attenuated in proliferation and cytolysis among normal cells. It would be a prominsing strategy for liver cancer tratment.