新的TOPK磷酸化位点S32参与高危前列腺癌进展及转移的机制和功能研究

To explore and research the function and regulatory mechanism of T-LAK cell-originated protein kinase (TOPK) during prostate cancer progression and metastasis can provide a new assessment factor and molecular target for prognosis and treatment of clinical prostate cancer. Our recently study found, TOPK highly expressed in high-risk prostate cancer. The experiments in vitro and in vivo confirmed that TOPK is associated with progression and metastasis of prostate cancer (Oncotarget Accepted: Feb27, 2015). However, the activation pathway and regulation mechanism are still unclear. In traditional view, the extracellular signal-regulated kinase ERK2 feedback activate TOPK in T9 site, our previously study found that the conclusion is incorrect, the new phosphorylation sites S32 which we discovered recently may play the key role in the process of TOPK activity regulation (Unpublished). The present study furtherly validate S32 site phosphorylation is important for activity regulation of TOPK via bioinformatic analysis and other methods to detect biological function; Discover the regulation mechanism involve in the prostate cancer progression and metastasis using cell transformation models and experiments in vivo, in vitro; Analysis and verify the phosphorylation of S32 is associate with prostate cancer progression in clinical with the prepared phospho -TOPK (S32) antibody. The above studies will be important in theoretical and prospect of clinical application.

探索研究T-LAK 细胞来源蛋白激酶TOPK在前列腺癌进展转移过程中作用及调控机制，可以为临床前列腺癌预后和治疗提供新的评估因子和分子靶点。最近我们发现：TOPK在高危前列腺癌高表达，细胞及动物实验证实TOPK与前列腺癌进展转移相关（Oncotarget Accepted）。但是，这一过程TOPK激活途径和调控机制尚不清楚。传统认为胞外信号调节激酶ERK2在T9位点反馈激活TOPK，我们前期研究发现该结论并不正确，我们新发现的S32位点磷酸化可能是该过程TOPK活性调控的关键（Unpublished）。本研究拟通过生物信息及功能学等方法进一步分析验证S32磷酸化对于TOPK活性调控的重要性，细胞转化模型和体内、体外实验研究该调控参与前列腺癌进展转移机制，分析S32位点磷酸化与前列腺癌进展临床相关性，上述研究具有重要的理论意义和临床应用前景。

TOPK是丝苏氨酸激酶，在各种肿瘤中高表达，与多种恶性肿瘤相关，其激活机制尚不清楚。已有报道显示TOPK和ERK2之间存在正反馈，并且其磷酸化位点为T9，我们前期研究发现T9并不是关键磷酸化位点，在本研究中，我们发现并证明了 S32 位点是 ERK2 磷酸化 TOPK 的一个新位点，证明了该磷酸化位点促进肿瘤转化的功能，验证了 TOPK和 ERK2 之间存在的正反馈环的存在。在临床相关性方面，本课题组研究了肾癌索拉菲尼耐药与 TOPK 磷酸化之间的关系，发现 TOPKS32 的磷酸化对索拉菲尼耐药具有指示作用，证明了 HGF/c-MET 是p-TOPK S32 表达升高的主要原因，并且提出索拉菲尼联合 TOPK 抑制剂可以逆转肾癌的索拉菲尼耐受。