染色质重塑基因ARID2在肝癌中的临床意义及相关功能研究

申请人前期通过外显子测序，发现一个肝癌中出现较高频率体细胞突变的染色质重塑基因ARID2。突变类型提示其可能为抑癌基因，且表现出HCV相关肝癌特异性倾向（结果发表在Nature Genetics上）。通过结构和功能分析并结合文献，推测ARID2发挥抑癌作用的途径包括影响PBAF复合物的稳定性和干扰素信号通路，但尚需进一步证实。本研究拟对更多肝癌标本的ARID2进行测序，并行免疫组化染色，以明确ARID2突变频率在HBV和HCV相关肝癌间是否存在差异，并结合临床随访资料判断其是否可作为预后标志。此外拟在肝癌细胞系中高表达ARID2、抑制ARID2表达及ARID2定位突变，并检测细胞生长和细胞周期的变化，证明其为抑癌基因并分析其关键结构域。同时采用RT-PCR和western blot法检测ARID2对PBAF其他亚基和干扰素通路中多个重要分子表达水平的影响，探讨其发挥抑癌作用的可能机制。

Our recent work described novel inactivating somatic mutations of ARID2 (AT-rich interactive domain 2) in HCC through exomic sequencing, which is a chromatin remodeling gene.The type of mutations suggested it was a tumor suppressor gene according to genetic principles. The mutations showed trends of advantage in HCV-related HCC than in HBV-related HCC. Functional studies have showed that ARID2 was essential for the stability of the PBAF complex and could impact the IFN signaling, through which it played a role as a tumor suppressor gene，as we hypothesized. So in this study, more HCV-related HCC and HBV-related HCC should be enrolled. Sequencing and IHC analysis of ARID2 in these patiens will be done to verify whether ARID2 is specific for HCV-related HCC and its clinical significance will be discussed. Furthermore, ARID2 of different expression level will be established in HCC cell lines, through plasmid or shRNA transfusion. Cell growth rate, cell cycle will be analyzed in these cell lines to demostrate that ARID2 is a TSG. Expression of subunits of PBAF complex and components of IFN signaling will also be examined to show the possible mechanism how ARID2 plays its role.