蝎毒多肽提取物联合雷帕霉素抑制H22肝癌肿瘤血管生成的作用机制研究

Research on inhibition mechanism of polypeptide extract from scorpion venom combined with Rapamycin on angiogenesis of H_(22) hepatoma

目的探讨蝎毒多肽提取物(PESV)联合雷帕霉素(RAPA)对H_(22)肝癌肿瘤血管生成的抑制作用并探讨可能的作用机制。方法 40只昆明小鼠,皮下接种H_(22)肝癌肿瘤细胞悬液建立荷瘤模型,随机分为模型组、PESV组(20 mg/kg)、RAPA组(2.5 mg/kg)和PESV+RAPA组(联合组),每组10只。连续药物干预14 d,隔日测量肿瘤体积,记录肿瘤生长曲线,计算抑瘤率。免疫组织化学法检测各组肿瘤组织的哺乳动物雷帕霉素靶蛋白(mTOR)、缺氧诱导因子-1α(HIF-1α)和血管内皮生长因子-A(VEGF-A)蛋白表达水平。以Ⅷ因子标记肿瘤微血管,计算微血管密度(MVD)。结果连续药物治疗14d后,PESV组、RAPA组、联合组肿瘤生长速度较模型组明显减慢(P<0.05、0.01),抑瘤率分别为17.7%、29.2%、44.8%。与模型组相比,3个给药组的mTOR、HIF-1α、VEGF-A的蛋白表达量降低(P<0.05、0.01),MVD不同程度降低(P<0.05、0.01)。联合组肿瘤体积以及蛋白表达量均低于RAPA组(P<0.05、0.01)。结论 PESV联合RAPA能够抑制H22肝癌小鼠肿瘤血管的生成,其作用机制可能与抑制肿瘤微环境中mTOR、HIF-1α、VEGF-A的蛋白表达有关。

Objective To study the inhibition ofpolypeptide extract from scorpion venom （PESV） combined with Rapamycin （RAPA） on angiogenesis of H22 hepatoma and its mechanism. Methods The H22 carcinoma cell suspension was subcutaneously inoculated into 40 Kunming mice. Thern tumor-beating mice were randomly divided into four groups, i.e., control group, PESV group （20 mg/kg）, RAPA group （2.5 mg/kg）, and PESV ＋ RAPA group, 10 mice in each group. The intervention was lasted 14 d. The tumor volume was measured once every other day, the tumor volume growth curve was drawn, and the tumor inhibitory rate was calculated. The protein expression levels of mammal target of RAPA （mTOR）, hypoxia-inducible factor-1α （HIF-1α, and vascular endothelial growth factor-A （VEGF-A） were detected by immunohistochemical assay. Microvessel was signed by factor Ⅷ and then detected by immunohistochemical assay. Results The growth speed of 1-122 hepatoma transplantation tumor was obviously inhibited in the PESV group, RAPA group, and PESV ＋ RAPA group compared with control group after 14 d intervention （P 〈 0.05, 0.01）, and the tumor inhibitory rates were 17.7%, 29.2%, and 44.8%. Immunohistochemical assay showed that the protein expression of roTOR, HIF-1α, and VEGF-A in the three drug groups was reduced compared with the control group （P 〈 0.05, 0.01 ）, and the MVD was reduced at different levels （P 〈 0.05, 0.01）. The tumor volume and the protein expression in PESV ＋ RAPA group are lower than those in RAPA group. Conclusion PESV ＋ RAPA could promote the inhibition on angiogenesis of H22 hepatoma, the mechanism maybe related to the inhibition on the protein expression ofmTOR, HIF- 1α, and VEGF-A.