Objective To investigate the roles of mouse erythroid differentiation and denucleation factor (MEDDF), newly cloned in our laboratory, in erythroid terminal differentiation. Methods Mouse erythroleukemia cells (MEL) were transfected with eukaryotic expression plasmid pcDNA-MEDDF. The changes of cell growth rate, mitotic index and colony-forming rate in semi-solid medium were investigated.The expressions of c-myc and β-globin genes were analysed by semi-quantitative RT-PCR. Results MEL cells transfected with pcDNA-MEDDF showed significant lower growth rate, mitotic index, and colony-forming rate in semisolid medium(P＜0.01).The percentage of benzidine-positive cells was 32.8% after transfection. The expression of β-globin in cells transfected with pcDNA-MEDDF was 3.43 times higher than that of control (MEL transfected with blank vector, pcDNA3.1 ), and the expression of c-myc was decreased by 66.3%.Conclusions MEDDF can induce differentiation of MELcell, and suppress its malignancy likely.

OBJECTIVETo investigate the expression of rat protamine (RP) gene in MEL cells and the effect on cell growth.

METHODSEukaryotic expression plasmid pCR-3.1-RP was constructed and transfected into MEL cells. The changes of cell growth rate, mitotic index and colony-forming rate in semi-solid medium were investigated.

RESULTSTransfected MEL cells showed lower growth rate, mitotic index and colony-forming rate. Volumes of cells were reduced and reduction of RNA transcription was observed.

CONCLUSIONThese results suggest that expression of RP in MEL cell may inhibit the cell growth and proliferation.

Animals ; Cell Division ; Leukemia, Erythroblastic, Acute ; genetics ; pathology ; Plasmids ; Protamines ; genetics ; metabolism ; Rats ; Transfection ; Tumor Cells, Cultured