Alteration of p60c-src expression in human leukemia-lymphoma cells correlated with induced differentiation.
Expression of cellular src-gene product (p60c-src) in human leukemia-lymphoma cell lines was analysed by flow cytometry using a monoclonal antibody (McAb), H2B4 which recognizes p60c-src protein in human cells. In several human leukemia-lymphoma cell lines (K562, Namalva, HL60, U937), p60c-src expression was higher than in peripheral mononuclear cells from healthy volunteers. Some non-lymphoid leukemia cells can be induced to differentiate into monocyte-macrophages by 12-O-tetradecanoyl phorbol-13-acetate (TPA). K562 cells were also induced to differentiate not only morphologically but also functionally into monocyte-macrophages by TPA. Flow cytometric analyses using the McAb H2B4 revealed that the amount of p60c-src expression in K562 cells markedly decreased during TPA induced differentiation. The activity of protein kinase associated with p60c-src in K562 cells was determined employing IgG of immunized rabbit serum specific for p60c-src. The immunized rabbit IgG heavy chain phosphorylation by protein kinase also decreased after the induced differentiation. We detected p60c-src protein in acute lymphoid leukemia cells as well as acute non-lymphoid leukemia cells freshly isolated from patients. The amount of p60c-src protein decreased in some acute non-lymphoid leukemia cases, but it increased in others after TPA induced differentiation. No correlation was observed between FAB classification of acute leukemias and the amount of endogenous p60c-src expression.
Irino
S
S
First Department of Internal Medicine, Kagawa Medical School, Japan.
Tanaka
T
T
Kubota
Y
Y
D002454:Cell Differentiation; D002460:Cell Line; D005434:Flow Cytometry; D006801:Humans; D007938:Leukemia / Q000235:genetics*; D008223:Lymphoma / Q000235:genetics*; D009000:Monocytes / Q000201:enzymology; D010587:Phagocytosis; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016392:Proto-Oncogene Proteins pp60(c-src); D011519:Proto-Oncogenes; D012016:Reference Values; D013755:Tetradecanoylphorbol Acetate
D011518:Proto-Oncogene Proteins; D011494:Protein Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); D013755:Tetradecanoylphorbol Acetate