Hemin is Transported in Human Leukemia K562 Cells and Interacts with DNA Sequences

Heme (ferroprotoporphyrin IX), a natural agent, serves as a prosthetic group in various hemoproteins like hemoglobin, myoglobin, cytochromes, catalase and others involved in oxygen transport, cellular respiration, ATP produetion and drug metabolism (Stryer, 1988). Hemin, the oxidised form of heme, has been shown to activate gene expression and promote differentiation in a variety of cell types including mouse 3T3 cells (Chen and London, 1981), neuroblastoma (Ishii et al, 1978), erythroleukemia (MEL, K562) cells (Ross et al, 1976; Rutherford et al, 1979a; Tsiftsoglou and Robinson, 1985; Tsiftsoglou et al, 1991) as well as normal hematopoietic cells like CFU-E, CFU-GM and BFU-E (Monette et al, 1982) by interacting with cellular components at various levels (Sassa et al, 1988).