title: Expression of the human T-cell-specific tyrosine kinase YT16 (lck) message in leukemic T-cell lines.
abstract: To evaluate the role of the human T-cell-specific tyrosine kinase lck (YT16), we measured the levels of lck expression in thymocytes, peripheral T-cells, and leukemia T-cell lines which are arrested at different stages of thymic differentiation. The results indicate that higher levels of the lck message can be found in total thymocytes and T-cells arrested at Stage III (thymocytes that have rearranged their alpha, beta, and gamma chain T-cell receptor genes). A 20-fold lower level of these transcripts, however, can be found in cells derived from Stage I cells (thymocytes with germline alpha, beta, and gamma genes), 4 times less messages in Stage II cells (thymocytes with rearranged gamma and beta chain genes, but with germline alpha chain genes), and a 4-fold lower amount of RNA in Stage IV cells (mature lymphocytes). Culture of these cells with a variety of inducing reagents indicated that leukemia cell lines of only Stages I and II can be induced to increase their levels of YT16 expression by the addition of tetradecanoyl phorbol-13-acetate. These results suggest that there may be a developmental regulation of these tyrosine kinase messages during T-cell ontogeny. The high level of these transcripts in more mature T-cell leukemia lines suggests that they may primarily play a role in the proliferative controls of these cells.
authors.affiliation: Department of Medical Biophysics, University of Toronto, Ontario, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
authors.forename: N
authors.initials: N
authors.lastname: Kimura
authors.forename: J
authors.initials: J
authors.lastname: Minowada
authors.forename: T W
authors.initials: TW
authors.lastname: Mak
mesh_terms: D000911:Antibodies, Monoclonal; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007938:Leukemia / Q000201:enzymology* / Q000235:genetics; D010835:Phytohemagglutinins / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D010835:Phytohemagglutinins; D011994:Recombinant Proteins; D011505:Protein-Tyrosine Kinases; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium