OBJECTIVETo investigate the effects of eukaryotic translation initiation factor 5A2 (EIF5A2) down-regulation by small interfering RNA (siRNA) on aggressiveness of human gastric cancer cell and its potential mechanisms.

METHODSThe expressions of EIF5A2 in human gastric cancer cell lines (MKN28 and HGC27) and immortalized gastric mucosal epithelial cells (GES-1) were measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. EIF5A2 gene in MKN28 cells was silenced by RNA interference and the inhibitory effect was evaluated by both qRT-PCR and Western blotting. Cell proliferation was assessed by CCK-8 assay. Cell migration and invasion were assessed by Transwell assay. The possible downstream targets of EIF5A2, such as CyclinD1, CyclinD3, matrix metallopeptidase-9 (MMP-9), E-cadherin, vimintin, C-myc, and metastasis-associated protein 1 (MTA1) expression levels, were examined by Western blotting.

RESULTSHigh expressions of EIF5A2 were found in MKN28 cells and human gastric adenocarcinoma tissues. Both EIF5A2 mRNA and protein expression in MKN28 cells were significantly down-regulated by siRNA#1 and siRNA#2, especially siRNA#1. Knockdown of EIF5A2 caused an apparent suppression of MKN28 cell proliferation (all P<0.01), migration (P<0.001), and invasion (P<0.001). After the knockdown of EIF5A2 in MKN28 cells, E-cadherin levels were upregulated, whereas vimentin, Cyclin D1, Cyclin D3, C-myc and MTA1 levels were downregulated.

CONCLUSIONKnockdown of EIF5A2 may inhibit MKN28 cell proliferation by downregulating the CyclinD1 and CyclinD3 and suppressing the cell migration and invasion by inhibiting MTA1, C-myc and epithelial-mesenchymal transition.