中文摘要：

eIF3a是真核翻译起始因子eUF3中最大的亚单位。许多研究表明，在酵母细胞和哺乳动物细胞中，eIF3a都参与了mRNA翻译的起始过程，并在蛋白质翻译起始过程中起重要调控作用。同时，eIF3a参与了细胞周期的调控，它与细胞的生长和分化存在着重要联系。最近的研究发现，eIF3a与肿瘤的发生、发展、预后和化疗疗效密切相关，且eIF3a基因多态性与恶性肿瘤的易感性也有一定相关性。本文对近年来eIF3a的生物学功能研究进展进行综述。

英文摘要：

eIF3a is the largest subunit of mammalian eukaryotic initiation factor 3 （eIF3）. It has been shown by many research that eIF3a plays an essential role in regulating the initiation of mRNA translation and protein translation in mammalian cells as well as yeast cells. Additionally, eIF3a involves in cell cycle regulation, which also influents cell proliferation and differentiation greatly. There is a close relationship between eIF3a and tumor progression, development, prognosis and chemotherapeutic efficacy, moreover the genetic polymorphisms of eIF3a associates with susceptibility of carcinoma. This review summarizes the research progress of eIF3a biological functions in recent years.