Abstract
Long-term cultures of K562(S) cells in 50–75 μM hemin allow the selection of ‘hemin-resistant’ K562 cells together with cells which proliferate efficiently while fully induced to express the human embryonic globin genes, as the hemoglobin Gower 1 (ζ2ε2) is the predominant hemoglobin produced. Our experiments demonstrate that these K562 cells accumulate mostly ɛ-globin mRNA (ɛ-globin mRNA/γ-globin mRNA=2.9) suggesting that the control of hemoglobin expression is at a pretranslational level.