Bisphosphorylated PEA-15 sensitizes ovarian cancer cells to paclitaxel by impairing the microtubule-destabilizing effect of SCLIP.
Bisphosphorylated PEA-15 sensitizes ovarian cancer cells to paclitaxel by impairing the microtubule-destabilizing effect of SCLIP.
复制标题
双磷酸化 PEA-15 通过削弱 SCLIP 的微管不稳定作用，使卵巢癌细胞对紫杉醇敏感。
DOI：
10.1158/1535-7163.mct-12-0737
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发表时间：
2013
影响因子：
5.7
通讯作者：
Ueno,NaotoT
中科院分区：
文献类型：
--
作者：
Xie,Xuemei;Bartholomeusz,Chandra;Ahmed,AhmedA;Kazansky,Anna;Diao,Lixia;Baggerly,KeithA;Hortobagyi,GabrielN;Ueno,NaotoT
紫杉醇是卵巢癌的标准化疗药物。PEA-15（富含星形胶质细胞的磷蛋白-15 kDa）调节细胞增殖、自噬、凋亡和葡萄糖代谢，还介导乳腺癌中AKT依赖性化学抗性。PEA-15的功能受到其Ser 104和Ser 116磷酸化状态的严格调节。然而，PEA-15磷酸化状态对癌细胞化学敏感性的影响仍然未知。在这里，我们测试的假设，PEA-15磷酸化在Ser 104和Ser 116（pPEA-15）敏感卵巢癌细胞紫杉醇。我们首先发现在PEA-15高表达的HEY和OVTOKO卵巢癌细胞中敲低PEA-15导致紫杉醇抗性，而在这些细胞中重新表达PEA-15导致紫杉醇敏化。我们接下来发现SKOV3.ip1-DD细胞（表达磷酸化模拟PEA-15）比SKOV3.ip1-AA细胞（表达非磷酸化PEA-15）对紫杉醇更敏感。与SKOV3.ip1-vector和SKOV3.ip1-AA细胞相比，SKOV3.ip1-DD细胞在紫杉醇作用下表现出细胞活力降低、锚定非依赖性生长抑制和凋亡增加。此外，HEY和OVTOKO细胞表现出增强的紫杉醇敏感性时，瞬时过表达拟磷酸化PEA-15和降低紫杉醇敏感性时，瞬时过表达nonphosphorylatable PEA-15。这些结果表明pPEA-15使卵巢癌细胞对紫杉醇敏感。cDNA微阵列分析表明，SCLIP（SCG 10样蛋白），微管不稳定蛋白，参与pPEA-15介导的化疗增敏。我们发现，紫杉醇治疗后SCLIP的表达减少和可能的翻译后修饰损害了SCLIP的微管不稳定作用，从而促进紫杉醇诱导有丝分裂阻滞和凋亡。我们的研究结果强调了pPEA-15作为改善卵巢癌紫杉醇治疗效果的有希望的靶点的重要性。©2013 AACR。
Paclitaxel is a standard chemotherapeutic agent for ovarian cancer. PEA-15 (phosphoprotein enriched in astrocytes-15 kDa) regulates cell proliferation, autophagy, apoptosis, and glucose metabolism and also mediates AKT-dependent chemoresistance in breast cancer. The functions of PEA-15 are tightly regulated by its phosphorylation status at Ser104 and Ser116. However, the effect of PEA-15 phosphorylation status on chemosensitivity of cancer cells remains unknown. Here, we tested the hypothesis that PEA-15 phosphorylated at both Ser104 and Ser116 (pPEA-15) sensitizes ovarian cancer cells to paclitaxel. We first found that knockdown of PEA-15 in PEA-15–high expressing HEY and OVTOKO ovarian cancer cells resulted in paclitaxel resistance, whereas re-expression of PEA-15 in these cells led to paclitaxel sensitization. We next found that SKOV3.ip1-DD cells (expressing phosphomimetic PEA-15) were more sensitive to paclitaxel than SKOV3.ip1-AA cells (expressing nonphosphorylatable PEA-15). Compared with SKOV3.ip1-vector and SKOV3.ip1-AA cells, SKOV3.ip1-DD cells displayed reduced cell viability, inhibited anchorage-independent growth, and augmented apoptosis when treated with paclitaxel. Furthermore, HEY and OVTOKO cells displayed enhanced paclitaxel sensitivity when transiently overexpressing phosphomimetic PEA-15 and reduced paclitaxel sensitivity when transiently overexpressing nonphosphorylatable PEA-15. These results indicate that pPEA-15 sensitizes ovarian cancer cells to paclitaxel. cDNA microarray analysis suggested that SCLIP (SCG10-like protein), a microtubule-destabilizing protein, is involved in pPEA-15–mediated chemosensitization. We found that reduced expression and possibly posttranslational modification of SCLIP following paclitaxel treatment impaired the microtubule-destabilizing effect of SCLIP, thereby promoting induction of mitotic arrest and apoptosis by paclitaxel. Our findings highlight the importance of pPEA-15 as a promising target for improving the efficacy of paclitaxel-based therapy in ovarian cancer.Mol Cancer Ther; 12(6); 1099–111. ©2013 AACR.