CAPS1通过调控外泌体途径影响肝癌发生、发展的机制研究

Exosomes released by secretory vesicles was an important factor of carcinogenesis and development of hepatocellular carcinoma (HCC). Previously we found the abnormal expression of calcium dependent activator protein for secretion 1 (CAPS1) which regulated the release of secretory vesicles in the serum of HCC patients by magnetic bead-based and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Further study showed that: 1. CAPS1 expression was reduced in clinical HCC tissues and HCC cell lines. 2. Reduced expression of CAPS1 was correlated with poor prognosis. 3. CAPS1 overexpression reduced the release of secretory vesicles and the quantity of exosomes, and suppressed cell proliferation and metastasis. 4. Rab27a, which was screened by immunoprecipitation and mass spectrum may correlate with CAPS1. All these study suggested that CAPS1 may participate in carcinogenesis and development of HCC by regulating exosome pathway. In the present study, we aim to further study the role of CAPS1 in carcinogenesis and development of HCC through exosome pathway by gene overexpression and interference, CAPS1 gene systemic knockout mice and clinical materials in cells, animals and clinical tissue level. Our study will provide new clues to understand the role of CAPS1 in HCC carcinogenesis and development.

分泌性囊泡释放的外泌体是影响肝癌发生、发展的重要因素。课题组前期应用磁性微球富集血清多肽谱，发现调节分泌性囊泡释放的钙离子依赖的分泌激活蛋白1（CAPS1）在肝癌患者血清中明显异常。进一步研究发现肝癌组织和肝癌细胞系CAPS1表达下调且CAPS1低表达与预后不良有关；CAPS1过表达减少肝癌细胞分泌性囊泡释放和外泌体数量，同时抑制细胞增殖、转移；免疫沉淀结合质谱筛选出可能的CAPS1相互作用蛋白Rab27a。提示肝脏表达的CAPS1可能通过调节外泌体通路，参与肝癌发生、发展过程。本课题拟利用基因过表达及干扰技术、基因敲除小鼠和临床肝癌资料，在细胞水平、动物水平和人体水平，进一步观察和探讨CAPS1通过调节外泌体途径，影响肝癌发生、发展的作用及机制，希望明确CAPS1在肝癌发生、发展中的作用及可能的机制。

分泌性囊泡释放的外泌体是影响肝癌发生、发展的重要因素。课题组前期应用磁性微球富集血清多肽谱，发现调节分泌性囊泡释放的依赖钙离子分泌的激活蛋白1（CAPS1）在肝癌患者血清中表达明显异常。进一步研究发现肝癌组织和肝癌细胞系CAPS1表达下调且肝内CAPS1低表达与预后不良有关。然而CAPS1如何影响肝癌细胞的发生发展，其机制尚不清楚。在本研究中，我们利用基因过表达及干扰技术，行体外功能学实验证实CAPS1上调可抑制肝癌细胞的侵袭迁移能力，并抑制EMT相关蛋白；CAPS1能够上调肝癌细胞外泌体数量，影响囊泡转运；机制研究表明，CAPS1主要通过抑制G6PD的二聚化抑制其酶活，进而抑制肝癌细胞的侵袭迁移能力和EMT；CAPS1在肝癌中的低表达源于miR-30d-5p的负性调控。本研究将CAPS1和肝癌的病理生理发生过程联系在一起，为研究CAPS1 在肝细胞癌中的功能提供新的线索。