紫草素对荷肝癌裸小鼠移植瘤生长的影响及其机制研究

摘要

目的:研究紫草素(Shikonin)对荷肝癌裸小鼠移植瘤生长的影响,并探讨其机制.方法:采用皮下注射接种肝癌HepG2细胞的方法建立荷肝癌裸小鼠模型,分别腹腔注射给予不同剂量紫草素(0.5、1、2 mg/kg)和顺铂(2 mg/kg)进行干预治疗,隔天一次,共给药6次.治疗完成后,观察各组裸小鼠一般生存状态及肿瘤生长状况,称取瘤体质量并计算抑瘤率;通过苏木精-伊红(HE)染色观察肿瘤组织形态结构改变,末端标记法(TUNEL)检测肿瘤组织细胞凋亡状况,免疫组织化学法(IHC)观察肿瘤组织凋亡相关蛋白(caspase-3、Bax、bcl-2)表达.结果:经紫草素治疗后荷肝癌裸小鼠饮食状况和精神状态明显改善,瘤体减小、活动度和硬度降低,肿瘤组织呈现细胞皱缩、片状坏死等病理性改变、凋亡细胞数量明显增多;瘤体质量显著减轻、抑瘤率显著升高;肿瘤组织中caspase-3和Bax表达显著上调而bcl-2显著下调,Bax/bcl-2比值显著升高;紫草素上述作用均具有一定的剂量依赖性.结论:紫草素对荷肝癌裸小鼠移植瘤生长具有一定的抑制作用,其机制可能与紫草素调节凋亡相关基因蛋白表达而促进肿瘤组织细胞凋亡有关.%Objective:To investigate the effects and mechanism of Shikonin on the growth of transplanted tumor in nude mice bearing hepatic carcinoma.Methods:HepG2 cell of hepatic carcinoma was used to make the models.Shikonin (0.5mg/kg,1 mg/kg,2 mg/kg) and Cisplatin (2mg/kg) were applied as the intervention,they were used once every other day for 6 times.The general state and tumor growth were observed,and the tumor was weighed to calculate the tumor inhibition rate in each group.The tumor histology was observed with HE staining;the apoptosis of tumor ceils was detected by TUNEL;and the expression of caspase-3,Bax,bcl-2 were detected by IHC.Results:The diet,mental condition,and tumor indicators were all improved in the nude mice intervened with Shikonin;also,in this group,tumor cell shrinkage and other pathological morphological changes appeared,the number of apoptotic cells in tumor tissue was significantly increased;the tumor weight were significandy decreased and tumor inhibition rate were significandy increased;the expression of Bax and caspase-3 were significantly increased,the expression of bcl-2 protein was significantly decreased,and the ratio of Bax/bcl-2 were significantly increased.All of above effects of Shikonin were dose-dependent.Conclusions:Shikonin has inhibitive effects on tumor growth in nude mice bearing hepatic carcinoma,which is perhaps related to its effects of regulating the expression of apoptosis-related genes and protein to promote tumor cell apoptosis.