六味地黄丸对小鼠移植性肝癌自杀基因治疗的增效作用

Synergism of Liuwei Dihuang Bolus on Suicide Gene Therapy for Murine Transplanted Hepatocarcinoma

【目的】观察六味地黄丸对小鼠皮下移植性肝细胞癌自杀基因治疗的增效作用,探讨建立中西医结合肿瘤自杀基因联合治疗方案的可行性。【方法】培养病毒包装细胞PT67/tk,病毒上清感染肝细胞癌细胞株H22后用G418筛选2周,获得抗性细胞克隆,命名为H22/tk并进行体外丙氧鸟苷(GCV)杀伤试验;证明杀伤活性后,将H22/tk与野生型H22按1∶4的比例混合后接种于昆明种小鼠皮下组织内造模,分为模型对照组、自杀基因治疗组、六味地黄丸治疗组和联合治疗组(N=20),并设正常对照组(N=10);六味地黄丸治疗从接种第2天起共15 d,GCV治疗从接种第6天起共11 d,观察疗效。【结果】体外实验中GCV对H22/tk肿瘤细胞具有明显的杀伤效应,表明体外病毒感染肝癌细胞成功,病毒携带的外源性自杀基因已表达且具有生物学活性。体内实验中于接种肿瘤细胞后第6天各组能触摸到肿瘤,成瘤率100%。自杀基因联合六味地黄丸治疗对小鼠移植性肝细胞癌生长速度具有明显抑制作用,以瘤块质量计算,其抑瘤率为63.0%(P<0.05);而单纯六味地黄丸治疗和单纯自杀基因治疗抑瘤率分别为46.3%和37.4%,但两者与模型组比较差异均无显著性意义。病理检查:各治疗组肉眼可见肿瘤体积均较模型对照组肿瘤体积小,以联合治疗组更明显。镜下可见各治疗组肿瘤细胞密度相对较低,肿瘤周围有较多纤维结缔组织增生及炎症细胞浸润,联合治疗组更明显,各组间差别以炎症细胞浸润最突出。【结论】六味地黄丸对小鼠移植性肝癌自杀基因治疗具有一定的增效作用,其疗效优于单纯自杀基因疗法或单纯六味地黄丸治疗。

[Objective] To observe the synergism of Liuwei Dihuang Bolus （LDB） on suicide gene therapy for murine transplanted hepatocarcinoma and to investigate the feasibility of estabhshing TCM-WM suicide gene therapy for the treatment of tumor. [Methods] Hepatocarcinoma cell H22 was transfected by the recombinant retmvirus in the culture supematant of virus-producing packaging cell PT67/tk, screened in G418 for 2 weeks and the anti-G418 tk ^＋ cell clone （named as H22/tk ） was obtained. After the activity of tk （thymidine kinase ） gene was confirmed by in-vitro ganciclovior （GCV） killing test, the tk ^＋ ceils （H22/tk） were mixed with tk^- ceils （wild type of H22） in the proportion of 1：4 and then were transplanted subcutaneously into murine oxter to induce the model. The injection amount was 2 × 10^6cells per mouse. The mice models were randomly divided into four groups （20 mice in each group） one day after injection： model control group, LDB group, tk/GCV group and the combined therapy group （ tk/GCV ＋ LDB）. Treatment of LDB began on the second day after inoculation and lasted 15 days, and the treatment of GCV also began on the second day and lasted 11 days. The curative effect was evaluated by observing the general state, tumor mass, tumor weight and pathohistological changes. [Results] GCV had an obvious killing effect on H22/tk ceils, indicating that hepatocarcinoma ceils were infected with virus in vitro successfully, and exogenous suicide gene packaged in the virus expressed and had biological activity. In-vivo experiment showed that the tumor mass could be touched in the mice 6 days after inoculation, the tumor formation rate being 100%. In the combined therapy group, the speed of tumor growth stepped down, the tumor-inhibition rate was 63.0% （ P 〈 0.05 as compared with that in the control group） while 46.3% in LDB group and 37.4% in tk/GCV group, and the differences were insignificant as compared with the control group. The results of pathological examination in the three treatment groups were as follows： lower density of tumor ceils, obvious proliferation of fibro-connective tissue around the tumor mass, and obvious infiltration of leukocytes especially in the combined therapy group. [ Conclusion ] LDB exerts a certain synergistic action with suicide gene therapy for murine transplanted hepatocarcinoma, which supplies preliminary data for the feasibility of establishing TCM-WM suicide gene therapy for tumor.