KPNA2通过运输c-Myc蛋白入核促进上皮性卵巢癌转移的机制研究

KPNA2 has a central role in nucleocytoplasmic transport and confirmed to have oncogenic function in a variety of malignant tumors. We confirmed that KPNA2 transported c-Myc into the nucleus in our previous studies. Related research results have been published in Cell Death Dis (2013). Recently, we found that the overexpression of KPNA2 significantly enhanced the ability of EOC cells to migrate and invade after transporting c-Myc into the nucleus. At the same time, we found that KPNA2 protein is detectable in the serum of EOC patients, and at significantly higher levels in patients with metastatic tumors than patients with non-metastatic tumors. Therefore, we hypothesized that KPNA2 promotes the metastasis of EOC, but its exact mechanism of action remains unclear. This project will establish KPNA2 stable high expression and the low expression of EOC cell line at first and screen out the mechanism of KPNA2 in promoting the metastasis of EOC using tumor metastasis related gene expression profile microarray. Then, confirmed the signaling pathways through in vivo and in vitro experiments. Finally, the serum levels of KPNA2 will be assessed in large numbers of patients with EOC to analyze the relationship between KPNA2 and EOC metastasis. The implementation of this project will have great significance for elucidating the mechanism of EOC metastasis.

KPNA2是核转运蛋白，负责核浆通讯，在多种恶性肿瘤中发挥癌基因功能。我们前期研究证实KPNA2可运输c-Myc蛋白入核，研究成果发表在Nature旗下子刊CDD（2013）。近日，我们发现KPNA2运输c-Myc蛋白入核后上皮性卵巢癌（EOC）细胞的迁移和侵袭能力明显增强；且发现EOC转移患者血清中KPNA2蛋白的含量显著高于未转移患者。据此，我们推测KPNA2通过调节c-Myc促进EOC转移，但其确切的作用机制还不清楚？本课题拟首先建立KPNA2稳定高表达及低表达EOC细胞株，利用我们自主研发的肿瘤转移相关基因表达谱芯片检测其表达谱的变化，经生物信息学分析，找出受其调控的c-Myc相关信号通路；再通过体外、体内实验证实此信号通路参与KPNA2促EOC转移的过程；最后，大样本检测血清中KPNA2的含量，进一步证实其与EOC转移的关系。本项目的实施对阐明EOC的转移机制具有十分重要的意义。

本项目在前期研究基础上，建立KPNA2稳定高表达细胞株和稳定低表达细胞株，进一步通过Transwell和Wound healing实验证实KPNA2具有促进上皮性卵巢癌（EOC）转移的作用；再通过自制肿瘤转移相关基因表达谱基因芯片筛查出TGF-β信号通路在不同KPNA2表达细胞株之间发生明显变化， Western blot及免疫荧光验证了TGF-β信号通路相关蛋白的表达变化，阐明了KPNA2通过运输c-myc蛋白进入细胞核，通过转录激活Akt/GSK-3β/Snail信号轴诱导EMT转化促进EOC转移的机理。最后，检测了46例健康女性志愿者及162例EOC患者血清中KPNA2的浓度，发现KPNA2在EOC患者血清中的浓度明显高于健康女性，并且KPNA2在血清中的浓度与EOC患者临床分期及淋巴结转移明显相关，血清中 KPNA2高表达EOC患者的总生存时间及无瘤生存时间明显短于 KPNA2低表达患者，血清中 KPNA2联合CA125检测较单纯CA125检测可明显提高早期EOC患的诊断率，诊断敏感性为：71.4%，特异性为：81.2%。本项目的研究成果对理解及阐明EOC的转移机制具有十分重要的科学意义，并且对优化EOC的早期诊断具有一定的临床转化价值。