Aberrance and modification of alpha-1- and alpha-2-globin gene expression in human and mouse erythroleukemia cells.

In contrast to normal human erythroid tissues where the alpha 2:alpha 1-globin mRNA ratio is about 72:28, in human erythroleukemia K562 cells this ratio was found to be quite low, i.e. about 8:92. The ratio was moderately increased by hemin induction and approached almost normal levels after chromosomal transfer from K562 to the mouse erythroleukemia (MEL) cells. We suggest that operationally positive regulatory factors may exist in erythroleukemia cells, modifying the relative alpha 1- and alpha 2-globin gene expression by events following induction and by the adult MEL environment. These factors may act by altering the relative rate of alpha 1- and alpha 2-globin mRNA synthesis.