Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spontaneous human lymphocyte-mediated cytotoxicity (SLMC) against tumour-cell targets was examined in a series of patients with localized or malignant disease, both treated and untreated, and patients with untreated chronic lymphocytic leukemia (CLL). The level of SLMC was assessed by means of two previously established assay systems; the xenogeneic assay involving the mouse mastocytoma line P815, and the allogeneic assay in which the human chronic myelogenous leukemia-derived line, K562, was used. The assay systems involve the use of Ficoll-Isopaque-separated, iron-plus-magnetism-purified lymphocytes in an overnight 51chromium release assay, and reflect the cytotoxic ability of human non-T, complement receptor-, Fc receptor-positive lymphocytes. In the present paper, lymphocytes from all normal donors tested showed significant activity in the SLMC assay, with some variation from day to day. This variation was markedly reduced when different normal donors were tested on the same day and under identical experimental conditions. In contrast, lymphocytes from many patients with malignant disease had decreased SLM activity, and this decrease was highly significant in patients with treated or untreated metastatic disease, or untreated CLL. This was also the case when the data were expressed relative to the number of cytotoxic cells in the normal control population, or in comparison to the relative SLMC activity of lymphocytes from patients with other conditions. Markedly decreased SLMC was observed in some patients in spite of normal T and B lymphocyte proportions, or the presence of the ability to mount a vigorous delayed hypersensitivity reaction to PPD. A comparison of the xenogeneic and allogeneic assays showed that the same information with respect to whether SLMC was normal or abnormal was obtained with both assays in the majority of cases. The significance of the data is discussed with respect to the possible role of SLMC in vivo and the relevance of SLMC to the assessment of specific cell-mediated cytotoxicity in malignant disease.
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PMID:Spontaneous human lymphocyte-mediated cytotoxicity againts tumour target cells. I. The effect of malignant disease. 82 77

Mastocytosis is associated with an activating mutation in the KIT oncoprotein (KITD816V) that results in autophosphorylation of the KIT receptor in a ligand-independent manner. This mutation is inherently resistant to imatinib and, to date, there remains no effective curative therapy for systemic mastocytosis associated with KITD816V. Dasatinib (BMS-354825) is a novel orally bioavailable SRC/ABL inhibitor that has activity against multiple imatinib-resistant BCR-ABL isoforms in vitro that is presently showing considerable promise in early-phase clinical trials of chronic myeloid leukemia (CML). Pharmacokinetic analysis suggests that high nanomolar concentrations of dasatinib can be achieved safely in humans. In this study, we demonstrate significant inhibitory activity of dasatinib against both wild-type KIT and the KITD816V mutation in the nanomolar range in in vitro and cell-based kinase assays. Additionally, dasatinib leads to growth inhibition of a KITD816V-harboring human masto-cytosis cell line. Significantly, dasatinib selectively kills primary neoplastic bone marrow mast cells from patients with systemic mastocytosis while sparing other hematopoietic cells. Computer modeling suggests that the KITD816V mutation destabilizes the inactive conformation of the KIT activation loop to which imatinib binds, but it is not predicted to impair binding of KIT by dasatinib. Based upon our results, further evaluation of dasatinib for the treatment of systemic masto-cytosis in clinical trials is warranted. Moreover, dasatinib may be of clinical utility in other disease settings driven by activating KIT mutations.
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PMID:Dasatinib (BMS-354825) inhibits KITD816V, an imatinib-resistant activating mutation that triggers neoplastic growth in most patients with systemic mastocytosis. 1643 89