Constitutive c-myb expression in K562 cells inhibits induced erythroid differentiation but not tetradecanoyl phorbol acetate-induced megakaryocytic differentiation.

AUTOR(ES)

Rosson, D

RESUMO

K562 cells were stably transfected with a plasmid vector constitutively expressing a full-length human c-myb gene. Parental cells possess the dual potential of inducibility of cellular differentiation along two lineages, i.e., erythroid and megakaryocytic. The resulting lineage is dependent on the inducing agent, with a number of compounds being competent to various degrees for inducing erythroid differentiation, while the tumor promoter tetradecanoyl phorbol acetate (TPA) induces a macrophage-like morphology with enhanced expression of proteins associated with megakaryocytes. Exogeneous expression of c-myb in transfected cell lines abrogated erythroid differentiation induced by cadaverine or cytosine arabinoside as assessed by hemoglobin production. However, TPA-induced megakaryocytic differentiation was left intact, as assessed by cell morphology, cytochemical staining, and the expression of the megakaryocytic antigens. These results indicate that c-Myb and protein kinase C play important roles in cellular differentiation of K562 cells and suggest that agents which directly modulate protein kinase C can induce differentiation in spite of constitutively high levels of c-Myb.

Documentos Relacionados

• Down-regulation of c-myb gene expression is a prerequisite for erythropoietin-induced erythroid differentiation.
• Regulation of c-myb expression in human neuroblastoma cells during retinoic acid-induced differentiation.
• Constitutive expression of a c-myb cDNA blocks Friend murine erythroleukemia cell differentiation.
• Suppression of Tetradecanoyl Phorbol Acetate-Induced Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus by K1 Signal Transduction
• Regulation of tetradecanoyl phorbol acetate-induced responses in NIH 3T3 cells by GAP, the GTPase-activating protein associated with p21c-ras.