Role of Ras/ERK-dependent pathway in the erythroid differentiation of K562 cells

Abstract

The chronic myelogenous leukemic K562 cell line carrying Bcr-Abl tyrosine kinase is considered as pluripotent hematopoietic progenitor cells expressing markers for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Here we investigated the signaling modulations required for induction of erythroid differentiation of K562 cells. When the K562 cells were treated with herbimycin A (an inhibitor of protein tyrosine kinase), r a s antisense oligonucleotide, and PD98059 (a specific inhibitor of MEK), inhibition of ERK/MAPK activity and cell growth, and induction of erythroid differentiation were observed. The r a s mutant, pZIPRas 6 1 l e u -transfected cells, K562-Ras 6 1 l e u , have shown a markedly decreased cell proliferation rate with approximately 2-fold doubling time, compared with the parental K562 cells, and about 60% of these cells have shown the phenotype of erythroid differentiation. In addition, herbimycin A inhibited the growth rate and increased the erythroid differentiation, but did not affect the elevated activity of ERK/MAPK in the K562-Ras 61leu cells. On the other hand, effects of PD98059 on the growth and differentiation of K562-Ras 61leu cells were biphasic. At low concentration of PD98059, which inhibited the elevated activity of ERK/MAPK to the level of parental cells, the growth rate increased and the erythroid differentiation decreased slightly, and at high concentration of PD98059, which inhibited the elevated activity of ERK/MAPK below that of the parental cells, the growth rate turned down and the erythroid differentiation was restored to the untreated control level. Taken together, these results suggest that an appropriate activity of ERK/MAPK is required to maintain the rapid growth and transformed phenotype of K562 cells.

Induction of erythroid differentiation by inhibition of Ras/ERK pathway in a Friend murine leukemia cell line

“…It should be emphasized, however, that the physiological relevance of these ®ndings with SKT6 cells to the normal erythroid di erentiation in vivo remains to be established in further studies. In fact, in a human chronic myelogenous leukemia cell line K562 which carries Philadelphia (BCR ± ABL) translocation, exogenous introduction of an activated ras gene was found to induce, rather than inhibit, erythroid di erentiation (Kang et al, 1999), suggesting that the contribution of certain signaling molecule can be quite di erent depending on genetic make-up of the cells under study.…”

The protein tyrosine phosphatase HePTP regulates nuclear translocation of ERK2 and can modulate megakaryocytic differentiation of K562 cells

“…Erythroid differentiation is also associated with changes in MAP-kinase signaling. 8,9 Therefore we asked whether modulation of HePTP expression would have any effect on the erythroid differentiation of K562 cells. For this purpose, we treated our various K562 cell lines with the kinase inhibitor Herbimycin A which induces erythroid differentiation (Ref.…”

“…9 Briefly, K562 cells were seeded at 5 × 10 4 cells per well in 12-well plates in complete medium. To induce erythroid differentiation cells were treated with the kinase inhibitor Herbimycin A (Sigma, St Louis, MO, USA) at a final concentration of 0.2 M. After 4 days the cells were washed with PBS and incubated with an equal volume of benzidine staining solution.…”

“…6,7 In these cells a low constitutive level of ERK activity is required for proliferation and treatment of the cells with the MEK inhibitor PD098059 results in downregulation of ERK activity and upregulation of erythroid markers. 8,9 Treatment of K562 cells with PMA, an activator of PKC, or expression of an activated MEK kinase induces prolonged ERK activity and megakaryocytic differentiation. 6,7 This differentiation process is characterized by cell cycle arrest, a change in the adhesive properties of the cells, and changes in cell morphology.…”

Effect of short-term ethanol on the proliferative response of Swiss 3T3 cells to mitogenic growth factors

“…Subsequent autophosphorylation of the receptors or their phosphorylation by receptor-associated protein kinases has been speculated to induce the activation of MAPK cascade including ERK and JNK (Pomerance et al, 1998). It was suggested that the dynamic balance between ERK and JNKs or p38 and the duration of MAPK activation would be important in determining the final cellular fate (Xia et al, 1995;Marshall, 1995;Chen et al, 1996;Kang et al, 1999). Differential effect of ethanol on the growth factorstimulated ERK and JNK might be another determinant for the final effect of ethanol on cell proliferation.…”