胞浆定位CCNY调控肺癌细胞迁移与侵袭的机制

Cyclin Y (CCNY) is one of the most highly conserved members of the cyclin superfamily which is distributed in cell membrane. Cyclin Y (called CycY in Drosophila), plays an essential role during embryogenesis of Drosophila via Wnt signal pathway. Recently, it is found that CCNY was also distributed in cytoplasm (CCNYcytoplasm). In our results, CCNY was mainly distributed in cytoplasm in non small cell lung cancer (NSCLC) tissues and lung cancer cells. The rate of lymphatic metastasis in NSCLC patients with CCNYcytoplasm positive expression were higher than that in NSCLC patients with CCNYcytoplasm negative expression. It indicates that CCNYcytoplasm plays more important roles than CCNYmembrane in human cancer progression. In H1299 and 95D cells, cell motility and invasiveness was weakened when CCNYcytoplasm was down-regulated. And the expression of tropomyosin 4 (TPM4, which provide stability to the filaments ) as well as its transcriptor AP1M2 (heterotetrameric adaptor-related protein complex 1 subunit mu-2) were also down-regulated. We speculated that CCNYcytoplasm could regulate cell motility and invasion via TPM4 and F-actin. In this project, the expression of CCNY in non-small cell lung cancer (NSCLC) tissues will be determined and the clinical significance of CCNYcytoplasm will be investigated. In order to study the function of CCNYcytoplasm in promoting cell migration and invasion, CCNYcytoplasm and CCNYmembrane will be overexpressed in NSCLC cells respectively. The function of CCNYcytoplasm on cell motility and invasion will be investigated. In order to study the mechanism of CCNYcytoplasm in regulating cell migration and invasion, the effect of CCNYcytoplasm on AP1M2 and TPM4 expression as well as the role of TPM4 in regulating cell metastasis potency will be discussed.

细胞周期素Y(cyclinY, CCNY)是一种调控果蝇发育的细胞膜蛋白。最近的研究发现，除细胞膜定位外，CCNY还存在胞浆分布的亚型。课题组研究说明在非小细胞肺癌组织与肺癌细胞中CCNY主要定位于细胞浆，推测在肺癌中胞浆CCNY具有更重要的功能；在非小细胞肺癌组织中，胞浆CCNY阳性的病人发生淋巴结转移的比率增加；在细胞系中，胞浆CCNY表达下调后，细胞迁移与侵袭能力受到了明显的抑制，微丝结合蛋白原肌球蛋白4(TPM4)表达明显下调，微丝亦发生解聚，这说明CCNY可能通过调控细胞微丝结构促进细胞转移能力。本课题将在已有研究基础上，对非小细胞肺癌及癌旁组织中CCNY的表达进行检测和分析，探讨胞浆表达CCNY的临床意义；同时应用胞浆CCNY过表达细胞株检测胞浆CCNY对细胞转移能力的影响，通过分析胞浆CCNY对TPM4及其转录因子AP1M2的表达调控作用，阐明胞浆CCCY促进细胞转移的机制。

细胞周期素Y(cyclinY, CCNY)是一种细胞周期蛋白，在进化上非常保守，说明它在细胞中具有重要的功能。最近的研究发现，CCNY具有两种不同的亚细胞定位：细胞膜定位和细胞浆定位，但对于两种不同的亚型在肿瘤细胞中的表达特点与功能尚未有相关报道。本课题对CCNY在非小细胞肺癌组织和细胞系中的表达特点和亚细胞定位进行了研究，并对CCNY的功能和分子机制进行了探讨。研究发现，在非小细胞肺癌组织与肺癌细胞中，CCNY主要定位于细胞浆，推测在肺癌中胞浆CCNY具有更重要的功能。本课题重点对胞浆定位CCNY的功能和分子机制进行了阐述。结果说明，在95D和H1299细胞中，CCNY表达下调后，细胞的迁移和侵袭能力受到了抑制，而在H1299细胞中，胞浆CCNY过表达后，细胞的迁移和侵袭能力明显增强，动物实验的结果也说明胞浆定位CCNY能够促进肿瘤的转移。Co-IP和免疫荧光结果显示在H1299细胞中，胞浆定位CCNY可与PFTK1结合，抑制PFTK1的表达可以抑制胞浆定位CCNY促进细胞迁移与侵袭的功能。通过差异表达谱芯片的结果，我们推测胞浆定位CCNY通过调节原肌球蛋白4 (TPM4, 一种肌动蛋白结合蛋白）的表达，影响细胞微丝骨架的组装。最后，免疫荧光染色的结果说明，胞浆CCNY的表达能够促进细胞微丝的组装和伪足的形成。通过本课题研究，我们认为CCNY通过不同的细胞定位实现不同功能，不同亚细胞定位的CCNY具有不同的作用。在非小细胞肺癌细胞中，胞浆CCNY通过与PFTK1结合，促进TPM4的表达，调控细胞微丝骨架的组装，进而调节细胞的迁移与侵袭能力。