蝎毒多肽促进5-氟尿嘧啶抑制H22肝癌血管生成的作用机制研究

Inhibitory mechanism of polypeptide from scorpion venom combined with 5-fluorouacil on angiogenesis of H_(22) hepatoma

目的探讨蝎毒多肽增强5-氟尿嘧啶(5-Fu)抑制肿瘤血管生成的机制。方法建立H22肝癌皮下荷瘤模型,随机分为模型组、蝎毒多肽(20 mg/kg)组、5-Fu(20 mg/kg)组、联合组(5-Fu+蝎毒多肽),每组20只。绘制肿瘤体积增长曲线并计算抑瘤率;免疫组织化学法检测各组肿瘤组织微血管密度(MVD)、PTEN、PI3K、P-Akt、缺氧诱导因子-1α(HIF-1α)的变化;Western blotting检测各组肿瘤组织中PTEN、PI3K、P-Akt、HIF-1α蛋白的表达。结果联合组、5-Fu组、蝎毒多肽组H22肝癌移植瘤的生长较模型组均受到明显抑制(P<0.05),联合组和5-Fu组瘤质量和肿瘤体积差异亦显著(P<0.05)。与荷瘤对照组相比,联合组明显下调PI3K、P-Akt、HIF-1α表达(P<0.01),上调PTEN表达(P<0.01),降低MVD(P<0.01)。结论蝎毒多肽可促进5-Fu抑制小鼠H22肝癌移植瘤血管生成,其机制可能与抑制肿瘤微环境中PI3K、P-Akt、HIF-1α的表达,上调PTEN的表达有关。

Objective To explore the inhibitory effects of polypeptide from scorpion venom （PSV） combined with 5-fluorouracil （5-Fu） on angiogenesis of H22 hepatoma in mice and its mechanism. Methods The H22 hepatoma tumor model was established by sc implanting H22 hepatoma cells into mice. The tumor-bearing mice were randomly divided into four groups： control, PSV （20 mg/kg）, 5-Fu （20 mg/kg）, and combination groups, 10 mice in each group. The effect of PSV on tumor growth was observed by recording tumor growth curve and calculating the inhibitory rate; Immunohistochemistry was applied to detecting microvessel density （MVD）, the levels of PTEN, PI3K, P-Akt, and hypoxia-inducible factor- 1 a （HIF- 1 a） in tumor tissue of mice in each group; Western blotting was applied to detecting the expression of PTEN, PI3K, P-Akt, and HIF- 1 a in tumor tissue of mice in each group. Results The growth of H22 hepatoma transplantation tumor was inhibited more obviously in the combination group, the 5-Fu group and PSV group than that in the H22 hepatoma tumor model group （P 〈 0.05）. There was statistical difference in the tumor weight and the tumor volume between the combination and the 5-Fu groups （P 〈 0.05）. Compared with the control group, the protein expression of PI3K, P-Akt, and HIF-1a significantly decreased while the protein expression of PTEN significantly increased in the combination group （P 〈 0.01）. The MVD was obviously lower in the combination group than that in the control and 5-Fu groups （P 〈 0.01）. Conclusion PSV combined with 5-Fu could inhibit the angiogenesis of H22 hepatoma transplantation tumor in mice. Its mechanisms might be associated with inhibiting the expression of PI3K, P-Akt, and HIF-1a and increasing PTEN in the microenvironment of tumors.