Inhibition of alpha-globin gene expression by RNAi.

RNA interference (RNAi), a process by which target messenger RNA (mRNA) is cleaved by small interfering complementary RNA (siRNA), is widely used for investigations of regulation of gene expression in various cells. In this study, siRNA complementary to 5' region of exon II of alpha-globin mRNA was examined for its role in erythroid colony forming cells (ECFCs) isolated from normal peripheral blood donor. On day 6 of cell culture, 1x10(6) ECFCs were transfected with lipofectamine-containing alpha-globin specific siRNA. After 48h of transfection, alpha-globin specific siRNA produced significantly reduction of alpha-globin mRNA level in a dose-dependent manner, but it did not affect the level of beta-globin mRNA. Significantly, decreased numbers of hemoglobinized erythroid cells relative to the control were observed supporting the inhibitory effect of this alpha-globin mRNA specific siRNA.