Inhibition of Expression of a Mouse α-Globin Gene by Plasmids that Include Antisense Oligonucleotides

Plasmid-borne DNAs, corresponding to 68-base oligodeoxynucleotides, synthesized in the anti-sense or sense configuration and based on the nucleotide sequences of various regions of the mouse α-globin mRNA, were introduced with the gene for xanthine-guanine phosphoribosyl transferase from E. coli (Ecogpt) into mouse erythroleukemia (MEL) cells by protoplast fusion. Specific inhibition of the synthesis of α-globin was observed only in the cells transformed with the plasmids with antisense 68-mers that corresponded to the cap site as well as the site of initiation of translation of α-globin mRNA (Oligo-A); Other plasmids with anti-sense 68-mers that corresponded to the regions of the exon/intron junctions, the individual exons, or the 3 untranslated region were ineffective. This antisense RNA efficiently reduced the production of α-globin to 9-18% of the endogenous level after induction with hexylmethylene-bis-acetoamide (HMBA). Moreover, most of the antisense transformants did not show any decrease in the expression of the c-myc gene at the early phases of differentiation of MEL cells. Thus, we propose a hypothesis that the early decline in levels of c-myc mRNA may be independent of and uncoupled from the program of globin synthesis during the differentiation of MEL cells.