c-Myb prevents TPA-induced differentiation and cell death in v-Myb transformed monoblasts.
Myelomonocytic cells transformed by v-Myb or altered forms of c-Myb do not contain the full-length c-Myb protein found in most immature hematopoietic cells. To determine if c-Myb was a dominant inhibitor of v-Myb, we have induced the synthesis of full-length c-Myb in monoblasts transformed by v-Myb. We found that although some morphological changes occurred, the presence of both c-Myb and v-Myb was compatible with cell growth. However, the response to phorbol ester (TPA) was significantly altered by c-Myb. Monoblasts transformed by v-Myb can be induced to differentiate into macrophages by treatment with TPA. This process is accompanied by a significant amount of cell death. However, when c-Myb was made TPA-inducible in these cells, TPA-induced differentiation into macrophages was blocked and cell death was prevented. These results demonstrate a significant difference in the biological effects of v-Myb and c-Myb in transformed myelomonocytic cells.
Smarda
J
J
Department of Pathology, Stanford University School of Medicine, California 94305-5324.
Lipsick
J S
JS
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D002645:Chickens; D009857:Oncogenes; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D020598:Proto-Oncogene Proteins c-myb; D011519:Proto-Oncogenes; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D013755:Tetradecanoylphorbol Acetate