Induction of erythroid differentiation by inhibition of Ras/ERK pathway in a friend murine leukemia cell line.
The role of Ras and MAP kinases (MAPKs) in the regulation of erythroid differentiation was studied using a cell line (SKT6) derived from Friend virus (Anemic strain)-induced murine erythroleukemia. This cell line undergoes differentiation in vitro in response to erythropoietin (EPO) or other chemical inducers such as dimethylsulfoxide (DMSO). When a constitutively active ras mutant (ras12V) was expressed in SKT6 cells, EPO-induced differentiation was inhibited. Conversely, a dominant negative ras mutant (ras17N) induced differentiation even in the absence of EPO, suggesting that the basal Ras activity is essential for the maintenance of the undifferentiated phenotype and proliferative potential in this cell line. Rapid inactivation of ERK was observed after expression of ras17N. Slow but significant inactivation of ERK was also observed during EPO-induced differentiation. Furthermore, overexpression of a constitutively active mutant of ERK-activating kinase (MAPKK) was found to suppress erythroid differentiation, while pharmacological inhibition of MAPKK induced differentiation. These findings suggest that down-regulation of Ras/ERK signaling pathway may be an essential event in EPO-induced erythroid differentiation in this system.
Matsuzaki
T
T
Department of Retroviral Regulation, Tokyo Medical and Dental University, Medical Research Division, 1-5-45 Yushima, Bunkyo-ku, Yushima, Tokyo 113-8519, Japan.
Aisaki
K i
Ki
Yamamura
Y
Y
Noda
M
M
Ikawa
Y
Y
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics*; D004121:Dimethyl Sulfoxide; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004921:Erythropoietin / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005622:Friend murine leukemia virus / Q000472:pathogenicity; D018014:Gene Transfer Techniques; D005799:Genes, Dominant; D005914:Globins / Q000187:drug effects / Q000235:genetics; D048031:JNK Mitogen-Activated Protein Kinases; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D048728:MAP Kinase Kinase Kinase 1; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D012097:Repressor Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D000077191:Wortmannin; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
D000730:Androstadienes; D004791:Enzyme Inhibitors; D005419:Flavonoids; D012097:Repressor Proteins; C034811:tetracycline resistance-encoding transposon repressor protein; D004921:Erythropoietin; D005914:Globins; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; C482578:Map3k1 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases; D018631:ras Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D000077191:Wortmannin; D004121:Dimethyl Sulfoxide