我们以前的国基课题（30600601）发现IQGAP1与甲状腺癌相关癌基因PPFP密切相关，进一步研究发现IQGAP1的表达增加在甲状腺癌转移灶中更为明显，且与miR-124表达与呈负相关。以上结果提示IQGAP1与甲状腺癌的侵袭转移密切相关，但究竟是通过何种机制促进甲状腺癌转移仍不明确。本项目拟在此研究基础上首先系统分析IQGAP1的表达水平改变对甲状腺癌侵袭转移的影响，阐明IQGAP1在甲状腺癌转移中扮演的角色；其次，通过改变miR-124在甲状腺癌细胞中的表达水平研究其对IQGAP1的调控作用及机制，进一步阐明miR-124在IQGAP1促进侵袭转移中的作用。最后，通过以串联亲和纯化耦联质谱技术为主的靶向蛋白质组学技术分离、鉴定甲状腺癌细胞中IQGAP1蛋白的相互作用蛋白，确定IQGAP1通过相关信号传导通路促进甲状腺癌侵袭转移的分子机理，为甲状腺癌转移的断治研究提供新线索。

Our previous NSFC project (30600601) demonstrated that IQGAP1 has close association with oncogene PPFP. Futher studies showed that increase of IQGAP1 was more obvious in metastasis compared with tumor tissues and has a negative correlation with miR-124 expression. All these results suggested that IQGAP1 has a close relationship with thyrod tumor invasion and metastasis. However, the details of action mechanism remains unclear. Firstly, the project will systematically analyse how the alteration of IQGAP1 expression affects the biological behavior of thyroid cancer especially invasion and metastasis. Secondly, the effect of miR-124 overexpression on IQGAP1 and the invasion and metastasis of thyroid cancer will be studied and IQGAP1 as the target gene of miR-124 will be validated. Therefore, the role of miR-124 in invasion and metastasis of thyroid cancer will be demonstrated. Lastly,technologies of tandem affinity purification(TAP) and targeted proteomics will be used to isolate and identificate the interacting protein of IQGAP1, and to explore the network characteristics of these protein interaction; addtionally, IQGAP1 functions via related signalling pathway will be comfirmed. All the studies will provide new clues to prevention and treatment of the invaison and metastasis of thyroid cancer.