title: Butyrate-induced erythroid differentiation of human K562 leukemia cells involves inhibition of ERK and activation of p38 MAP kinase pathways.
abstract: Butyrate induces cytodifferentiation in many tumor cells of different origin, suggesting that an as yet unidentified common mechanism inherent to malignant cells is the target of butyrate action. This study determined the role of different mitogen-activated protein (MAP) kinase signal transduction pathways in butyrate-induced erythroid differentiation of K562 human leukemia cells. Using a panel of anti-ERK, JNK, and p38 phosphospecific antibodies, the study showed that phosphorylation of ERK and JNK is decreased following treatment of cells with butyrate, whereas phosphorylation of p38 is increased. In contrast, a K562 subline defective in butyrate-mediated induction of erythroid differentiation did not reveal these changes in phosphorylation patterns. Inhibition of ERK activity by UO126 induces erythroid differentiation and acts synergistically with butyrate on hemoglobin synthesis and inhibition of cell proliferation, whereas inhibition of p38 activity by SB203580 completely abolished induction of hemoglobin expression by butyrate. Taken together, our data suggest a model in which butyrate induces erythroid differentiation of K562 cells by inhibition of ERK and activation of p38 signal transduction pathways.
authors.affiliation: Children's Hospital, University of Göttingen, Göttingen, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Witt
authors.forename: K
authors.initials: K
authors.lastname: Sand
authors.forename: A
authors.initials: A
authors.lastname: Pekrun
mesh_terms: D002087:Butyrates / Q000494:pharmacology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004912:Erythrocytes / Q000473:pathology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020014:K562 Cells; D004915:Leukemia, Erythroblastic, Acute / Q000201:enzymology / Q000473:pathology*; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D002087:Butyrates; D004791:Enzyme Inhibitors; D011494:Protein Kinases; D048056:Mitogen-Activated Protein Kinase 9; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases