RESUMO
<p><b>OBJECTIVE</b>To construct an eukaryotic expression vector of open reading frame of unknown KH gene (KH-ORF), and investigate its effect on cell proliferation.</p><p><b>METHODS</b>The pCI-neo-KH-ORF expression vector was constructed by DNA recombinant technique and was introduced into COS-7 cells and K562 cells by lipofectactin-mediated DNA transfection. Expression of KH-ORF mRNA was detected by RT-PCR. The effect of KH-ORF on cell cycle of COS-7 cells and K562 cells was evaluated by flow cytometry (FCM). Effect on cell proliferation of COS-7 cells was tested by MTT assay and that on K562 cells was analyzed by growth curves and LDH activity measurement.</p><p><b>RESULTS</b>(1) KH-ORF mRNA was expressed both in COS-7 cells and K562 cells. (2) The cell cycle and cell proliferation of COS-7 cells were unaffected significantly. (3) The proportion of cells in S phase was increased in pCI-neo-KH-ORF-transfected K562 cells; and growth curves and LDH activity indicated enhanced cell proliferation.</p><p><b>CONCLUSION</b>KH gene may be a leukemia gene related to proliferation of K562 cells.</p>