DCLK1调控NF-κB诱导EMT与“干性维持”促进前列腺癌转移的机制研究

Tumor metastasis is the critical cause of death in prostate cancer (PCa), while efficient molecular targeting PCa metastasis is still absent. Our previous studies confirmed that DCLK1, a member of the protein kinase superfamily, could promote the invasion, migration and epithelial-mesenchymal transition (EMT) of PCa cells. Moreover, patients with high DCLK1 expression in PCa tissues were more likely to have seminal vesicle and lymph node invasion, suggesting that DCLK1 was closely related to PCa metastasis. Further studies demonstrated that DCLK1 could increase the expression of p65, an active subunit of NF-kappa B in PCa cells. Since DCLK1 has been reported involved in cancer stem cells (CSCs) stemness, we propose a novel mechanism of PCa metastasis induced by DCLK1: upregulated DCLK1 activates NF-kappa B signaling pathway through the nuclear translocation of p65 after I-kappa B degradation, following the enhanced expression of target genes, which induces EMT and CSCs stemness, thereby promoting PCa metastasis. Through a series of experiments in vivo and in vitro, this project will elucidate the molecular mechanism of PCa metastasis triggered by DCLK1, so as to (1) explore the relationship between DCLK1 and NF-kappa B; (2) confirm the role of DCLK1 in promoting PCa metastasis via inducing EMT and CSCs stemness; (3) elucidate the possible mechanism of DCLK1 in regulating NF-kappa B signaling pathway. The project will finally provide important molecular intervention targets for inhibiting PCa metastasis.

肿瘤转移是前列腺癌（PCa）致死的主要原因，但目前缺乏高效PCa转移抑制靶标。我们前期研究证实蛋白激酶DCLK1能够促进PCa细胞的侵袭、迁移及EMT，PCa组织中DCLK1高表达患者更易精囊与淋巴结侵犯，提示其与PCa转移密切相关。进一步研究发现PCa中DCLK1可能上调NF-κB/p65活性。鉴于已报道的DCLK1促肿瘤干细胞（CSCs）干性维持作用，我们提出DCLK1调控NF-κB通路，降解IκB后促进p65入核，上调相关靶基因表达，诱导EMT与CSCs干性维持，进而促进PCa转移的假说，并通过临床样本及体内外实验综合验证。拟解决：1）探寻DCLK1与NF-κB之间的联系；2）证实DCLK1诱导EMT与干性维持促进PCa转移的作用；3）阐明DCLK1调控NF-κB信号通路促进PCa转移的可能机制。最终为抑制PCa的转移提供重要分子干预靶点。

肿瘤进展转移是前列腺癌（PCa）致死的主要原因，但目前缺乏高效PCa转移抑制靶标。我们在预实验基础上扩大样本量，证实PCa组织中蛋白激酶DCLK1与NF-κBp65均在转移性PCa中高表达，且二者表达水平正相关。随后功能实验确定DCLK1能够诱导PCa干性维持。进一步探索发现PCa中DCLK1为NF-κBp65上游调控基因，且DCLK1诱导的侵袭及迁移由NF-κB 所调控，但NF-κB并未介导DCLK1诱导的EMT及干性维持。因此，我们在新方向上进行了探索，对TCGA数据库中478例PCa样本miRNA调控转录组进行非负矩阵分解并验证后获得了一组同时与EMT及PCa干性维持密切相关的miRNA序列。随后，对上述PCa样本基因组进行生物信息学分析发现DCLK1表达与Hippo通路关键分子密切相关，进一步综合实验证实DCLK1可能通过调控Hippo通路促进PCa干性维持。综上，本课题为DCLK1可能通过miRNA相关通路调控EMT及PCa干性维持的机制探索提供了研究基础与线索。揭示DCLK1通过Hippo通路诱导PCa干性维持并促进PCa进展转移，为PCa新的药物治疗靶点提供了理论依据。