[A novel erythroid differentiation related gene EDRF1 upreguated globin gene expression in HEL cells]

To observe the differentiation-inducing properties of the novel erythroid differentiation related gene EDRF1, and demonstrate its functioning pathway involved in regulation of alpha- and gamma-globin gene expression.

EDRF1 sense and antisense constructs were transfected into HEL cells, then the expression of globin and erythropoietin receptor gene was identified by Northern blot analysis. RT-PCR and electrophoresis mobility shift assay (EMSA) were carried out to monitor the expression and DNA-binding activity of erythroid specific transcription factor GATA-1 and NF-E2.

In HEL cells with transfection of sense expression carrier, the experssion of EDRF1 mRNA was upregulated. In HEL cells with transfection of antisense expression carrier, the experession of EDRF1 mRNA was downregulated. In HEL cells with overexpression of EDRF1, production of alpha-globin was increased. In antisense EDRF1 overexpressed HEL cells, significant loss of alpha- and gamma-globin mRNA synthesis was observed. The expression of erythropoietin receptor was unchanged in HEL cells transfected with EDRF1 sense and antisense expression carriers. No significant change was found in expression of transcription factors GATA-1 and NF-E2 in HEL cells transfected with empty carrier, sense expression carrier, and antisense expression carrier. However, the transcription activity of GATA-1 was severely impaired. Expression of erythropoietin receptor gene was not influenced by EDRF1 gene overexpression.

EDRF1 regulates alpha- and gamma-globin gene synthesis by modulating DNA-binding activity of GATA-1 transcription factor. Overexpression and underexpression of EDRF1 do not significantly regulate the expression of GATA-1 and NF-E2 mRNA. Monitoring the EPOR signal pathway is not the mechanism by which EDRF1 influences the differentiation of erythrocyte.