人参皂苷Rg3对小鼠肺腺癌移植瘤生长抑素受体表达的调控及意义

目的:探讨人参皂苷Rg3对肺腺癌小鼠移植瘤生长和转移的抑制作用及其可能的机制.方法:接种Lewis细胞构建高转移肺腺癌小鼠移植瘤模型,随机分为对照组(0.9％氯化钠溶液)、顺铂(cisplatin,DDP)组和人参皂苷Rg3组；肿瘤细胞接种后4d给予相应药物干预,接种后24 d处死小鼠,剥离皮下肿瘤并取出肺组织,计算抑瘤率和肺表面结节转移抑制率；应用免疫组织化学法检测移植瘤组织中生长抑素受体( somatostatin receptor,SSTR)、血管内皮生长因子(vascular endothelial growth factor,VEGF)和增殖细胞核抗原(proliferation cell nuclear antigen,PCNA)的表达水平,TUNEL法检测移植瘤中肿瘤细胞的凋亡情况.结果:DDP组和人参皂苷Rg3组的抑瘤率分别为39.20％和54.86％ (P＜0.01).DDP组和人参皂苷Rg3组的肺表面结节转移抑制率分别为30.25％和58.57％,差异有统计学意义(P＜0.05).人参皂苷Rg3组中SSTR的表达水平和肿瘤细胞凋亡指数高于对照组和DDP组(P＜0.01),人参皂苷Rg3组中VEGF的表达水平和PCNA增殖指数低于对照组和DDP组(P＜0.01,P＜0.05).结论:人参皂苷Rg3对肺腺癌小鼠移植瘤的生长和转移具有明显抑制作用,其机制可能与SSTR的过表达有关.

The regulatory effect of ginsenoside Rg3 on expression of somatostatin receptor in lung carcinoma allografts in mice and its significance

Objective:To investigate the inhibitory effects of ginsenoside Rg3 on the growth and metastasis of lung carcinoma allografts in mice, and to explore the possible mechanism. Methods:The mice bearing a metastatic variant of Lewis lung carcinoma were established, and then they were randomized to receive 0.9% sodium chloride solution (as a control), DDP (cisplatin), and ginsenoside Rg3 from the fourth day after transplant, respectively. Until the twenty-fourth day after transplant, the mice were sacrificed. The subcutaneous tumor was dissected, and the lung was removed. The inhibitory rate of tumor growth and the number of metastatic foci on the lung surface were counted. The expressions of SSTR (somatostatin receptor), VEGF (vascular endothelial growth factor) and PCNA (proliferation cell nuclear antigen) in subcutaneous tumor were examined by immunohistochemistry. The apoptosis was detected by TUNEL (terminal transferase-mediated dUTP nick end-labeling) method. Results:The inhibitory rates of tumor growth in DDP-treated group and the ginsenoside Rg3-treated group were 39.20% and 54.86%, respectively (P < 0.01). The numbers of metastatic foci on the lung surface in DDP-treated group and the ginsenoside Rg3-treated group were decreased by 30.25% and 58.57%, respectively (P < 0.05). The expression level of SSTR and the apoptosis index in the ginsenoside Rg3-treated group were higher than those in the control group and the DDP-treated group (P < 0.01), while the expression level of VEGF and the proliferation index of PCNA in the ginsenoside Rg3-treated group were decreased as compared with the control group and the DDP-treated group (P < 0.01, P < 0.05). Conclusion:Ginsenoside Rg3 can inhibit the growth and metastasis of lung carcinoma allografts in mice. The mechanism may be associated with the overexpression of SSTR.