Cyclin A confers CDDP resistance to endometrial carcinoma cells via activation of PI-3K pathway

Cyclin A 通过激活 PI-3K 通路赋予子宫内膜癌细胞 CDDP 抗性

基本信息

批准号：
17591726
负责人：
KATO Kiyoshi
金额：
$ 2.24万
依托单位：
SHINSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591726/
关键词：
cyclin A apoptosis chemoresistanse Endometrial carcinoma periplakin chemotherapy PI3-kinase pathway MAP kinase

项目摘要

Our objective of this study was to examine the hypothesis that the cyclinA overexpression in endometrial cancer may influence the growth of the endometrial caricnima cell as well as the sensitivity to anticancer drugs.To access this hypothesis, we first established a stable cyclin A expressing endometrial carcinoma cell line (cyc A HHUA), which demonstrated an increased proliferative activity and resistance to chemotherapeutic agents. We also observed that the increased resistance was accompanied with reduced apoptosis after the exposure to anticancer drugs. The following immunoblotting study revealed that the resistance was in part due to the increased expressions of antiapoptotic factor, Bcl-2 as well as the inactivation of proapoptotic factor, Bad. We then evaluated the involvement of PI3K-Akt antiapoptotic pathway. Activating phosphorylation was augmented after the exposure to CDDP in cyc A HHUA compared with the control, suggesting that the PI-3K pathway plays an important role in cyclinA-induced CDDP resistance.To further examine the mechanisms of cyclin A-induced CDCP resistance, we performed an oligonucleotide array analysis between the cycA HHUA and control HHUA to identify new molecules involved in the antiapoptotic effects of cyclinA. The analysis revealed that an Akt-binding protein, periplakin (PPL), was up-regulated in cyc A HHUA. Immunoprecipitation showed that the Akt-binding fraction of PPL was also increased along with the increased expression of cyclin A. Transfection of PPL-specific siRNA successfully reduced Akt phosphorylation, indicating that the binding of PPL to Akt stabilized the PI3K-Akt pathway signaling.In conclusion, we have newly revealed that the cyclin A exerted an antiapoptotic effect repoponsible for CDDP resistance in endometrial cancer cells, and that the effect was mediated via the stabilization of Akt pathway by PPL.

我们本研究的目的是检验子宫内膜癌中cyclinA过度表达可能影响子宫内膜癌细胞的生长以及对抗癌药物的敏感性的假设。为了验证这一假设，我们首先建立了稳定表达cyclinA的子宫内膜癌细胞系（cyc A HHUA），表现出增殖活性增加和对化疗药物的耐药性。我们还观察到，接触抗癌药物后，抵抗力的增加伴随着细胞凋亡的减少。以下免疫印迹研究表明，耐药性部分是由于抗凋亡因子 Bcl-2 表达增加以及促凋亡因子 Bad 失活所致。然后我们评估了 PI3K-Akt 抗凋亡途径的参与情况。与对照相比，cyc A HHUA 暴露于 CDDP 后激活的磷酸化增强，表明 PI-3K 通路在 cyclinA 诱导的 CDDP 抗性中发挥重要作用。为了进一步研究 cyclin A 诱导的 CDCP 抗性的机制，我们在 cycA HHUA 和对照 HHUA 之间进行寡核苷酸阵列分析，以鉴定参与 cyclinA 抗凋亡作用的新分子。分析显示，Akt 结合蛋白 periplakin (PPL) 在 cyc A HHUA 中表达上调。免疫沉淀显示，PPL 的 Akt 结合分数也随着 cyclin A 表达的增加而增加。转染 PPL 特异性 siRNA 成功降低了 Akt 磷酸化，表明 PPL 与 Akt 的结合稳定了 PI3K-Akt 通路信号传导。结论，我们新发现，细胞周期蛋白 A 发挥抗凋亡作用，与子宫内膜癌细胞的 CDDP 耐药性有关，并且该作用是通过稳定化介导的PPL 的 Akt 通路。