蝎毒多肽提取物促进环磷酰胺抑制Lewis肺癌的作用机制研究

Study on the Mechanism of Polypeptide Extract from Scorpion Venom to Promote the Restraint of Cyclophosphamide on Lewis Lung Cancer

目的探讨蝎毒多肽提取物增强环磷酰胺抗肿瘤的机制。方法建立小鼠Lewis肺癌皮下荷瘤模型,随机分为荷瘤对照组(模型组)、环磷酰胺(cyclophosphamide,CTX)组、蝎毒多肽提取物(polypeptideextract from scorpion venom,PESV)组和联合组(CTX+PESV组),每组10只。记录肿瘤生长曲线,并采用逆转录PCR法和免疫组织化学法检测肿瘤微环境中免疫抑制因子血管内皮生长因子-A(VEGF-A)和转化生长因子-β1(TGF-β1)的表达变化,采用免疫荧光化学法检测肿瘤组织中树突细胞(dendritic cells,DCs)表型CD80、CD86的表达变化。结果连续治疗21天后,联合组Lewis肺癌移植瘤的生长明显抑制(P<0.05);与模型组相比较,PESV组中CD80、CD86的表达有所增强,而CTX组中CD80、CD86的表达有所下降,联合组与CTX组相比强度和表达量均有所增加;与模型组比较PESV组和CTX组TGF-β1和VEGF-A mRNA表达量均降低(均P<0.05);与PESV组和CTX组比较,联合组TGF-β1和VEGF-A的mRNA表达量均降低(P<0.05)。结论 PESV可抑制Lewis肺癌中VEGF-A和TGF-β1的表达,促进DC的成熟,恢复其抗原摄取提呈功能,逆转CTX对机体的免疫损伤,从而起到诱导肿瘤细胞凋亡的作用。

Objective To explore the mechanism of polypeptide extract from scorpion venom（PESV） on promoting anti-tumor effects of cyclophosphamide（CTX）.Methods The Lewis lung tumor model was established by subcutaneously implanting Lewis lung cells into C57BL/6 mice.The tumor-bearing mice were randomly divided into 4 groups,i.e.,the model group,the cyclophosphamide（CTX） group,the polypeptide extract from scorpion venom（PESV） group,and the combination group（CTX＋PESV）,10 mice in each group.The tumor growth curve was recorded.Changes of vascular endothelial growth factor-A（VEGF-A） and transfroming growth factor-β1（TGF-β1） expressions in the tumor microenvironment were detected using reverse transcription PCR and immunohistochemical assay.Changes of dendritic cells（DCs） phenotype CD80 and CD86 expressions in the tumor tissue were detected using immunofluorescence chemical assay.Results After 21 successive days of treatment,the growth of Lewis lung cancer transplantation tumor in the combination group was obviously inhibited（P0.05）.Compared with the model group,the expressions of CD80 and CD86 in the PESV group was somewhat enhanced,while those in the CTX group was somewhat lowered.Compared with the CTX group,the fluorescent signal strength and expressions in the combination group somewhat increased.Compared with the model group,the expressions of TGF-β1 and VEGF-A mRNA decreased in the PESV group and the CTX group（both P0.05）.Compared with the PESV group and the CTX group,the expressions of TGF-β1 and VEGF-A in the combination group both decreased（both P0.05）.Conclusion PESV could inhibit the expressions of VEGF and TGF-β1,promote the maturation of DCs,recover its antigen uptake presentation function,and reverse the immune injury to the body by CTX,thus playing a role in inducing the tumor cell apoptosis.