The human ELAV(embryonic lethal abnormal vision)-like protein HuR stabilizes a certain group of cellular mRNAs that contain AU- ri ch elements in theil‘ 3’• untranslated region, Dysregulation of mRNA s tability may be relevant in tumor biology and may lead to abnormal expression of several proteins in malignant tumors, The aim of this study is to identify the differentially expressed proteins according to the functi onal activi ty of HuR Methods : We used stabl e expression of small interfering RNA(siRNA) of HuR gene to inhibit the expression of HuR in human ora l car cinoma cell lines‘ KB cell line and YD10B cell line‘ and compared the proteomic changes between s iRNA-treated and cont rol cell line using two-dimensional gel electrophoresis , Flow cytometry caliber scan(FACS) was employed to investigate the effects of HuR on cell apoptosis and proliferation , Results: Seventeen differentially expressed proteins between the two cell lines were identified by electrospray ioruzati on quadrupole time-of- fl ight mass spectrometry(ESI-Q-TOF MS) and database searching, Among them there are eleven proteins which are significant ly up- regulated in siRNA- treated cell line, which include heat shock protein 10(influencing nucl eocytoplas rnic transpo 다， cell dedifferentiation , and inhibition of apoptosis) , keratin 19(basal cell differ ent iat ion) ‘ and nucleoside diphosphate kinase B(G protein activator), etc Enolase 1 and Ml of pyruvate kinase a re the representatives of signifi cantly down-regulated proteins in siRNA-treated cell 11l1e Conclusion : Our data suggest that HuR participate in mRNAs stability of proteins that have the counter effects in the carcinogenesis of oral ca ncer , And the functiona l proteomics a re needed to elucidate the detailed interactions between HuR and t hese molec ules