Hypoxia induced paclitaxel resistance in human ovarian cancers via hypoxia-inducible factor 1α
Hypoxia induced paclitaxel resistance in human ovarian cancers via hypoxia-inducible factor 1α
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DOI：
10.1007/s00432-009-0675-4
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发表时间：
2010-03-01
影响因子：
3.6
通讯作者：
Ma, Ding
中科院分区：
文献类型：
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作者：
Huang, Lei;Ao, Qilin;Ma, Ding
化疗耐药性严重限制了抗癌药物对人类卵巢癌的有效治疗，卵巢癌已被证明在特定的低氧环境中发展和存活。为了了解缺氧与化疗耐药之间的关系，我们研究了缺氧在化疗耐药的病理生理学中的潜在作用，特别关注缺氧诱导因子1 α（HIF-1 α）。A2780卵巢癌细胞在梯度缺氧条件下培养MTT法测定细胞对紫杉醇的敏感性及细胞抑制率。分别采用Western blot、免疫细胞化学染色、逆转录-聚合酶链反应（RT-PCR）和双荧光素酶报告系统检测HIF-1 α的表达和转录活性。流式细胞仪分析细胞周期分布。此外，我们通过RNA干扰技术沉默HIF-1 α的表达，MTT法显示低氧刺激显著降低了细胞对紫杉醇的敏感性。与此同时，细胞核中的HIF-1 α被激活，表现出转录活性增加和高蛋白表达。低氧处理（5%O-2，类似于1%O-2）显著增加了G 0/G1期的细胞群。有趣的是，内源性HIF-1 α的敲低可显著增强A2780细胞的耐药性，并促进G1/S期转换，同时增加A2780细胞对紫杉醇的敏感性，提示低氧刺激HIF-1 α通过阻滞G 0/G1期在耐药中发挥关键作用。通过siRNA消除低氧条件或沉默HIF-1 α可能提供一种有效的工具来增强紫杉醇治疗人类卵巢癌的有效性。
Chemoresistance severely restricts the anti-cancer medicines from effectively treating human ovarian cancer, which has been shown to develop and survive in the specific hypoxic environments. To understand the relationship between hypoxia and chemoresistance, we investigated the potential role of hypoxia in the pathophysiology of chemoresistance, especially focusing on hypoxia-inducible factor 1 alpha (HIF-1 alpha).The A2780 ovarian cancer cells are cultured in gradient hypoxic conditions (5% O-2, 3% O-2, and 1% O-2), the sensitivity of the cells to paclitaxel and the cell inhibitory rate were determined by MTT assay. The expression and the transcriptional activity of HIF-1 alpha were examined by western blot, Immunocytochemical staining, reverse transcription-polymerase chain reaction (RT-PCR), and the dual luciferase reporter system, respectively. The cell cycle distribution was analyzed by flow cytometry. In addition, we silence HIF-1 alpha expression by performing RNA interference.MTT assay demonstrates that hypoxic challenge substantially reduces the susceptibility of cells to paclitaxel at all the tested concentrations. Coincident with this is the activation of HIF-1 alpha in nuclear, which displays the increased transcriptional activity and high protein expression. Hypoxic manipulation (5% O-2, similar to 1% O-2) significantly increased the cell population at G0/G1. Interestingly, knockdown of endogenous HIF-1 alpha significantly alleviates the chemoresistance and promotes G1/S transition with the increased sensitivity of A2780 cells to paclitaxel under each hypoxic condition.It suggests that HIF-1 alpha, stimulated by hypoxia, exerts a pivotal role in chemoresistance by G0/G1 arrest. Eliminating hypoxic conditions or silencing HIF-1 alpha by siRNA might provide a potent tool to enhance paclitaxel effectiveness in treatment of human ovarian cancer.