过表达缺氧诱导因子1α影响前列腺癌血管生成的体内研究

目的:观察转染缺氧诱导因子1α(HIF-1α)在体内环境下对人前列腺癌血管形成的影响,并探讨其分子机制。方法:对构建的转染HIF-1α人前列腺癌LNCaP细胞(LNCaP/HIF-1α)复苏后培养,ELISA法检测转染前后培养液上清PSA水平;流式细胞术检测细胞周期;将转染前后的LNCaP细胞建立免疫裸鼠皮下肿瘤模型,观察肿瘤生长情况;收集肿瘤标本后针对肿瘤血管生成相关蛋白血管内皮生长因子(VEGF),诱导型一氧化氮合酶(iN-OS),促血管生成素2(Ang-2)行免疫组化染色。结果:与LNCaP细胞相比,转染HIF-1α的人前列腺癌LNCaP细胞培养液PSA水平明显降低(t=8.243,P<0.05);流式细胞术显示其更具有增殖活性。体内实验显示皮下肿瘤成瘤率提高,成瘤时间提前。LNCaP/HIF-1α免疫组化研究显示VEGF、iNOS、Ang-2表达较LNCaP组增强。结论:在体内环境下,HIF-1α过表达能够诱导人前列腺癌LNCaP细胞血管形成相关蛋白VEGF、iNOS表达上调,提高肿瘤血管形成能力。并通过诱导肿瘤血管形成来增强肿瘤的侵袭转移能力;体内外实验显示HIF-1α可能对人前列腺癌LNCaP细胞Ang-2表达不产生影响,而在体内环境下Ang-2表达受其他因素调控。

Over-expression of Hypoxia-inducible Factor 1 Alpha Increases Angiogenesis of LNCaP Cells in vivo

OBJECTIVE: To observe the influence of hypoxia-inducible factor 1 alpha (HIF-1alpha) on angiogenesis in prostate carcinoma in vivo and to investigate its molecular mechanism. METHODS: LNCaP/HIF-1alpha and LNCaP cells were cultured, the level of PSA in the supernatant of the culture medium detected by ELISA assay before and after the transfection, and the cellular cycle measured by flow cytometry. Nude mouse models of subcutaneous tumor were established with LNCaP/HIF-1alpha and LNCaP cells, the tumor growth observed, and tumor specimens collected for immunohistochemical staining. RESULTS: Compared with the LNCaP cells, LNCaP/HIF-1alpha cells showed an obviously decreased PSA level (t = 8.243, P < 0.05) and enhanced proliferous activity. The tumorigenesis rate increased and the tumorigenesis time advanced in the LNCaP/HIF-1alpha group of the nude mice. Immunohistochemistry displayed higher expressions of VEGF, iNOS and Ang-2 in the LNCaP/HIF-1alpha than in the LNCaP group. CONCLUSION: The over-expression of HIF-1alpha can up-regulate VEGF and iNOS involved in angiogenesis in vivo and contribute to the invasive potency of LNCaP cells. HIF-1alpha may have no influence on Ang-2 either in vitro or in vivo, while the expression of Ang-2 is regulated by other factors in vivo.