The specificity of expression of the isolated 5'-flanking sequences of the human beta- and epsilon-globin genes was examined in the K562 human erythroleukemia cell line, the murine erythroleukemia (MEL) cell, and in nonerythroid cell lines CV-1, HeLa-S3, and WI-38.
In non-erythroid cells (or in mouse erythroleukaemia (MEL) cells in which adult but not embryonic globin genes are expressed) transcription of the epsilon-globin gene occurs mainly from a site 200 bp upstream of the major cap site (the -200 cap site).
To study the expression of globin genes in human cells, human epsilon-globin genes were transferred into a K562 cell line, Bos, which synthesizes very low amounts of epsilon-globin mRNA.