Apolipoprotein A-I Mimetic Peptides Inhibit Expression and Activity of Hypoxia-Inducible Factor-1α in Human Ovarian Cancer Cell Lines and a Mouse Ovarian Cancer Model
Apolipoprotein A-I Mimetic Peptides Inhibit Expression and Activity of Hypoxia-Inducible Factor-1α in Human Ovarian Cancer Cell Lines and a Mouse Ovarian Cancer Model
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DOI：
10.1124/jpet.112.191544
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发表时间：
2012-08-01
影响因子：
3.5
通讯作者：
Farias-Eisner, Robin
中科院分区：
文献类型：
--
作者：
Gao, Feng;Chattopadhyay, Arnab;Farias-Eisner, Robin
我们以前的研究结果表明，载脂蛋白A-I（apoA-I）模拟肽L-4F和L-5 F抑制血管内皮生长因子的产生和肿瘤血管生成。本研究旨在测试apoA-I模拟肽是否抑制缺氧诱导因子-1 α（HIF-1 α）的表达和活性，HIF-1 α在血管生成因子和血管生成的产生中起关键作用。免疫组化法检测肿瘤组织中HIF-1 α的表达。采用免疫印迹、实时荧光聚合酶链反应、免疫荧光和荧光素酶活性测定等方法检测HIF-1 α在人卵巢癌细胞系中的表达和活性。免疫组化染色显示L-4F处理显著降低小鼠卵巢肿瘤组织中HIF-1 α的表达。L-4F抑制低氧浓度、氯化钴（CoCl 2，一种低氧血症化合物）、溶血磷脂酸和胰岛素诱导的两种人卵巢癌细胞系OV 2008和CAOV-3中HIF-1 α的表达和活性。L-4F对胰岛素诱导的Akt磷酸化无影响，但可抑制细胞外信号调节激酶和p70 s6激酶的激活，从而抑制HIF-1 α的合成。用L-4F预处理显著加速胰岛素和CoCl 2处理的细胞中HIF-1 α的蛋白酶体依赖性蛋白降解。L-4F对HIF-1 α表达的抑制作用部分由L-4F的活性氧清除作用介导。ApoA-I模拟肽在体内和体外模型中都抑制HIF-1 α的表达和活性，这表明HIF-1 α的抑制可能是apoA-I模拟肽抑制肿瘤进展的关键机制。
Our previous results demonstrated that the apolipoprotein A-I (apoA-I) mimetic peptides L-4F and L-5F inhibit vascular endothelial growth factor production and tumor angiogenesis. The present study was designed to test whether apoA-I mimetic peptides inhibit the expression and activity of hypoxia-inducible factor-1 alpha (HIF-1 alpha), which plays a critical role in the production of angiogenic factors and angiogenesis. Immunohistochemistry staining was used to examine the expression of HIF-1 alpha in tumor tissues. Immunoblotting, real-time polymerase chain reaction, immunofluorescence, and luciferase activity as-says were used to determine the expression and activity of HIF-1 alpha in human ovarian cancer cell lines. Immunohistochemistry staining demonstrated that L-4F treatment dramatically decreased HIF-1 alpha expression in mouse ovarian tumor tissues. L-4F inhibited the expression and activity of HIF-1 alpha induced by low oxygen concentration, cobalt chloride (CoCl2, a hypoxiamimic compound), lysophosphatidic acid, and insulin in two human ovarian cancer cell lines, OV2008 and CAOV-3. L-4F had no effect on the insulin-induced phosphorylation of Akt, but inhibited the activation of extracellular signal-regulated kinase and p70s6 kinase, leading to the inhibition of HIF-1 alpha synthesis. Pretreatment with L-4F dramatically accelerated the proteasome-dependent protein degradation of HIF-1 alpha in both insulinand CoCl2-treated cells. The inhibitory effect of L-4F on HIF-1 alpha expression is in part mediated by the reactive oxygen species-scavenging effect of L-4F. ApoA-I mimetic peptides inhibit the expression and activity of HIF-1 alpha in both in vivo and in vitro models, suggesting the inhibition of HIF-1 alpha may be a critical mechanism responsible for the suppression of tumor progression by apoA-I mimetic peptides.