title: The bcr-c-abl tyrosine kinase activity is extinguished by TPA in K562 leukemia cells.
abstract: Tyrosine kinase activity is associated with the transforming potential of several oncogenes. Human chronic myeloid leukemia (CML) cells and cell lines have been shown to contain an active bcr-c-abl p210 tyrosine kinase as a consequence of the Philadelphia chromosomal translocation. In the present work the activity of the c-abl and c-src oncogene-encoded tyrosine kinase was investigated during phorbol diester (TPA) induced differentiation of the K562 CML cells. The high tyrosine kinase activity of p210bcr-c-abl is strongly reduced during the initial 24 h of TPA treatment. In contrast, the activity of the c-src tyrosine kinase is not changed. No change occurs in the expression of the c-abl-specific RNAs during this period. Following the reduction of bcr-c-abl kinase activity, cell proliferation is arrested and megakaryoblastic antigens appear on the cells. Sodium butyrate caused a slight decrease in growth rate and of bcr-c-abl kinase activity during erythroid differentiation whereas no changes in c-src or c-abl tyrosine kinase activities were seen in DMSO-treated control cells.
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D006801:Humans; D007122:Immunoelectrophoresis; D007700:Kinetics; D007951:Leukemia, Myeloid / Q000201:enzymology*; D009857:Oncogenes / Q000187:drug effects*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D011505:Protein-Tyrosine Kinases; D013755:Tetradecanoylphorbol Acetate