Guggulsterone inhibits angiogenesis by blocking STAT3 and VEGF expression in colon cancer cells
Guggulsterone inhibits angiogenesis by blocking STAT3 and VEGF expression in colon cancer cells
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DOI：
10.3892/or_00000147
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发表时间：
2008-12-01
期刊：
影响因子：
4.2
通讯作者：
Cheon, Jae Hee
中科院分区：
文献类型：
--
作者：
Kim, Eun Soo;Hong, Sung Yi;Cheon, Jae Hee
植物甾体酮已被证明具有抗肿瘤作用，使其成为一种候选的化疗药物。我们研究了谷固酮对结肠癌细胞的抗肿瘤作用，并阐明了与血管生成相关的潜在分子机制。细胞存活实验检测谷甾酮对细胞的诱导凋亡作用。Western印迹法检测信号转导和转录激活因子3(STAT3)、血管内皮生长因子(VEGF)、缺氧诱导因子-1α(HIF-1α)和芳烃受体核转位蛋白(ARNT)等多种下游细胞内血管生成相关蛋白的表达水平。采用染色质免疫沉淀法，我们检测了谷固酮是否影响STAT3、ARNT和HIF-1α对人血管内皮生长因子启动子的募集。为探讨苦参酮对血管内皮细胞迁移和侵袭的影响，采用人脐静脉内皮细胞(HUVECs)进行了血管内皮细胞的成管和迁移实验。明胶酶谱法检测基质金属蛋白酶-2和-9活性。谷固酮以剂量依赖的方式显著降低结肠癌细胞的存活率，并在低氧条件下显著阻断血管内皮生长因子、ARNT和STAT3的表达。古古斯特酮可抑制STAT3和Arnt的募集，但不能抑制HIF-1α对VEGF启动子的募集。在谷固酮作用下，HUVECs产生大量缩短和严重断裂的管子，迁移活性降低。此外，酶谱分析显示，在谷固酮存在的情况下，基质金属蛋白酶-2和-9的活性明显降低。本研究结果提示谷甾酮不仅可诱导结肠癌细胞凋亡，还可通过阻断STAT3和血管内皮生长因子的表达抑制结肠癌细胞的血管生成和转移，提示其在结直肠癌治疗中具有潜在的应用价值。
The plant sterol guggulsterone has been shown to exert anti-tumor effects, making it a candidate chemotherapeutic agent. We investigated the anti-tumor effects of guggulsterone on colon cancer cells and elucidated the underlying molecular mechanisms related to angiogenesis. The apoptotic effects of guggulsterone were examined by cell survival assay. Western blot analysis was used to determine the levels of various down-stream intracellular proteins involved in angiogenesis, including signal transducer and activator of transcription 3 (STAT3), vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1 alpha (HIF-1 alpha) and aryl hydrocarbon receptor nuclear translocator (ARNT). Using chromatin immunoprecipitation assay, we tested whether guggulsterone affects the recruitment of STAT3, ARNT and HIF-1 alpha to the human VEGF promoter. To investigate the effect of guggulsterone on vascular endothelial cell migration and invasion, tube formation and migration assays were conducted using human umbilical vein endothelial cells (HUVECs). Matrix metalloproteinase (MMP)-2 and -9 activities were measured by gelatin zymography. Guggulsterone significantly reduced cell viability in colon cancer cells in a dose-dependent manner and blocked VEGF, ARNT and STAT3 expression prominently in hypoxic conditions. The recruitment of STAT3 and ARNT, but not HIF-1 alpha, to the VEGF promoter was inhibited by guggulsterone treatment. HUVECs produced much foreshortened and severely broken tubes and showed decreased migration activity under guggulsterone effects. In addition, zymography revealed that MMP-2 and -9 enzyme activities were markedly lower in the presence of guggulsterone. The results of this study suggest that guggulsterone not only induces apoptosis, but also inhibits angiogenesis and metastasis in colon cancer cells by blocking STAT3 and VEGF expression, suggesting its therapeutic potential in the treatment of colorectal cancer.