ABSTRACT
<p><b>OBJECTIVE</b>The study was to investigate the effect of silencing Eps8 gene expression on proliferation and apoptosis of human leukemia K562 cells and its molecular mechanism.</p><p><b>METHODS</b>The expetriments were divided into 3 groups, including blank control group(K562 cells without treatment), K562-shRNA group(K562 cells transfected by specific Eps8-shRNA lenticiral vector) and K562-NC group(K562 cells transfected by negtive control lenticiral vector). K562 cells with stably-silenced Eps8 gene were constucted by lentibirus-mediated RNA technology. The efficacy of transfection was observed by fluorescence microscopy and the changes of Eps8 mRNA and protein level were detected by RT-PCR and Western blot respectively. Cell proliferation was confirmed by typan blue exclusion and MTT method. The apoptosis rate of cells was analysed by the flow cytometry, and colony forming was detected by methylcellulose colony forming assay. The protein level change of phosphrylated-AKT were detected by Western blot.</p><p><b>RESULTS</b>Stably-silenced Eps8 gene K562 cells and the negative control cells were successfully constructed. Compared with the blank control group and the K562-NC group, the proliferation of K562-shRNA cells were siginificantly inhibited(P<0.05); the apoptosis of K562-shRNA cells increased(P<0.05). In addition, the methylcellulose colony forming assay showed that the colony forming was dramatically suppressed in K562-shRNA cells (P<0.05). Furthermore, knocking down Eps8 gene reduced the protein level of AKT phosphrylation at both residue Ser437 and Thr308(P<0.05), while there was no obvious change in the level of total-AKT(P>0.05). Knocking down Eps8 gene reduced the protein level of m-TOR phosphrylation and PRAS40 phosphrylation (P<0.05), while there was no obvious change in the level of total-mTOR and PRAS40 (P>0.05).</p><p><b>CONCLUSION</b>Silencing Eps8 gene through lentvirus can inhibit the cell proliferation and promote the apoptosis of human leukemia K562 cells, which possibly relates with the inhibition of AKT/mTOR activation.</p>