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)

Imatinib mesylate (IM), is a selective and competitive inhibitor of tyrosine kinases, including BCR-ABL, ABL, KIT, and the platelet-derived growth factor receptors (PDGF-R). It binds to the ATP-binding site of the target kinase and prevents the transfer of phosphate from ATP to the tyrosine residues of various substrates. At oral doses of 200-600 mg, the majority of patients with chronic myeloid leukaemia, Philadelphia chromosome-positive acute lymphoblastic leukemia expressing the BCR-ABL fusion protein and gastrointestinal stromal tumours (GIST) achieve a bio-molecular and clinical response, frequently complete, associated with limited toxicity. Several other human cancers, as small-cell lung carcinoma, melanoma, seminoma, some sarcomas, and adenoid cystic carcinomas may over-express KIT or PDGF-R, and clinical trials to evaluate the role of IM in the treatment of such cancers are currently ongoing. We determined c-KIT with Dako CD 117 antibody in 5 cases of advanced ocular melanoma (OM) and we found positive immuno-reactivity for CD 117 in three patients. We treated all patients with palliative-use IM at the oral dose of 400 mgr daily. We obtained in expressing positive immuno-reactivity for CD 117 patients: a reduction of malignant ascites in one, a partial remission in the neck nodes in another, and progression of liver metastases in the third. Evidences of progression has been reported in the other two patients expressing negative immuno-reactivity for CD 117. We conclude that the effect of IM should be assessed only in OM with positive immuno-histochemical c-kit (CD 117) expression. IM might be a potential therapeutic strategy for these patients.
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PMID:Tyrosine kinase inhibitor imatinib mesylate as anticancer agent for advanced ocular melanoma expressing immunoistochemical C-KIT (CD 117): preliminary results of a compassionate use clinical trial. 1676

Why does it seem that, repeatedly, when a new treatment with a striking effect is discovered in the cancer field, it is effective for a very rare cancer type? For example, groundbreaking therapeutic discoveries have been made for extremely uncommon malignancies such as hairy cell leukemia, chronic myelogenous leukemia, seminoma, gastrointestinal stromal tumor, (del)5q myelodysplastic syndrome, and acute promyelocytic leukemia. In contrast, progress in the most common and most intensively studied tumors - lung, breast, prostate, and colon cancer - has been slow and incremental. We hypothesize that the reason for this phenomenon is that the pathophysiologic basis for a tumor being rare is one and the same as the reason that it may ultimately be so treatable. That is, if a cancer can be derived only via a single aberrant molecular genetic aberration, then it should be both rare and easily targeted by a molecular cancer therapeutic approach. If, on the other hand, many distinct pathways can lead to the development of a specific tumor type, it should occur much more commonly and be significantly more difficult to treat. The corollary to our hypothesis is the prediction that new therapies will continue to show their most salutary effects in rare cancers. Furthermore, only by stratifying the common tumors, especially when using targeted agents, into the molecular subsets of diseases that compose them are we likely to achieve a substantial effect in these disorders.
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PMID:Uncommon tumors and exceptional therapies: paradox or paradigm? 1743 Nov

Although circulating hematopoietic progenitor cells (HPCs) are frequently used in therapeutic approaches, many aspects of their cellular biochemistry are still unclear. In the present study, the effects of cyclic nucleotide-elevating agents on HPC proliferation and differentiation were investigated. HPCs from different sources, including healthy persons, patients with tumors (medulloblastoma, seminoma, or multiple myeloma), and patients with chronic myelocytic leukemia (CML), were compared. HPCs were isolated by standard leukapheresis procedures and analyzed for proliferation and differentiation into the megakaryocytic and granulocytic lineages. HPCs contained high concentrations of cyclic guanosine monophosphate (cGMP)-dependent and cyclic adenosine monophosphate (cAMP)-dependent protein kinases G and A (PKG and PKA, respectively). Whereas PKG was partly down-regulated during culture, the PKA level remained constant. Stimulation of PKG in HPCs isolated from healthy donors or tumor patients resulted in a biphasic reaction: low cGMP concentrations inhibited proliferation and stimulated differentiation into megakaryocytes, whereas high concentrations revealed the opposite effect. In contrast, differentiation into granulocytes was inhibited in a concentration-dependent manner. Stimulation of PKA inhibited HPC differentiation; however, HPC proliferation was inhibited in controls and stimulated in HPCs from tumor patients. HPCs isolated from CML patients showed a nonhomogeneous reaction pattern to both cyclic nucleotides with high variability between the individual donors. We demonstrated the importance of the source of HPCs for the investigation of proliferation and differentiation. Cyclic nucleotide-regulated pathways are clearly involved in HPC proliferation and differentiation. Pharmacological strategies using cyclic nucleotide-elevating substances to influence HPC growth and differentiation in the bone marrow might support current strategies in HPC recovery from the peripheral blood.
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PMID:Cyclic nucleotide-regulated proliferation and differentiation vary in human hematopoietic progenitor cells derived from healthy persons, tumor patients, and chronic myelocytic leukemia patients. 1820 72