TRIM9及其家族蛋白在肿瘤发生过程中的功能研究

The TRIpartite Motif (TRIM) proteins, a family of E3 ubiquitin ligases containing RING domain, are involved in multiple biological processes and related to some disorders and diseases. We recently demonstrated that TRIM9, a member of TRIM family protein, directly targeted and regulated beta-transducin repeat-containing protein (beta-TrCP), the substrate recognizing component of the Skp–Cullin–F-box-containing (SCF) E3 ubiquitin ligase complex (Nat. Commun. 2014). Some substrates of beta-TrCP are well-characterized to be related to tumorigenesis, for example, p53 and MDM2. TRIM9 was found to be highly expressed in brain but not other tissue and was up-regulated in some carcinomas. Our preliminary data show that TRIM9 is directly under control of p53, the well-known tumor suppressor, and TRIM9 potentially play a critical role in tumor cell proliferation and survival. In this proposal, we’ll further study the molecular mechanism of TRIM9 and p53 interaction. TRIM9 knockout (KO) and p53 KO mice will be used to confirm the in vivo functions. In the other hand, some members of TRIM proteins had been found to be involved in cancer. But no systemic study for the whole TRIM family has been performed so far. To do this, the established TRIM family protein cDNA library and single guide RNA (sgRNA) library for CRISPR-CAS9 system against TRIM gene will be employed to screen tumor proliferation, survival and metastasis , which will uncover some novel TRIM members involved in cancer development and provide new targets for cancer therapy.

TRIM家族蛋白，是一类RING类型泛素E3连接酶，参与各种生物过程并与很多疾病相关。我们新近鉴定了TRIM9的功能，发现它直接作用于b-TrCP,并调控后者的功能(Nat. Commun. 2014).b-TrCP是 SCF泛素链接酶复合物中负责底物识别的组分，其多个底物与肿瘤密切相关。TRIM9正常仅表达于脑部组织，但在多种肿瘤中也高表达。初步研究表明TRIM9表达直接受p53调控，对肿瘤的增值和生存有着重要作用。在本项目中，我们将进一步研究TRIM9与p53相互作用及分子机制。使用TRIM9和p53基因敲除小鼠，验证他们在体内的功能。此外，目前已经发现多个TRIM家族成员参与肿瘤发生，我们将使用已经构建好的TRIM家族蛋白cDNA文库和sgRNA文库进行系统性研究。这不仅有助于我们更好地了解TRIM家族蛋白的功能，而且有助于我们更深入探讨肿瘤的发生，并为肿瘤治疗提供新的靶点。