Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autonomous, factor-independent growth and differentiation of malignant cells in preleukemic and leukemic disease states is a well-recognized phenomenon and is often associated with a poor prognosis. Mast cells are distinct hematopoietic cells and express a unique profile of antigens. Growth and differentiation of normal mast cells is dependent on mast cell growth factor (MGF), the ligand of the c-kit protooncogene product. In this study, we screened for mast cell-lineage involvement in 52 patients suffering from myeloid leukemias, myelodysplastic syndromes (MDS), systemic mastocytosis, or other diseases by probing for mast cell-related molecules (c-kit, tryptase, histamine, and MGF) and by analyzing kit ligand/MGF-independent growth of mast cells in long-term suspension culture. Of the 52 patients tested, 2 patients with refractory anemia with excess of blast cells in transformation and 1 patient suffering from chronic myeloid leukemia blast crisis (CML-BC) were diagnosed as mastocytic disease. These patients were characterized by complex chromosomal abnormalities, splenomegaly, high percentages of circulating metachromatic cells (5% to 25%), high levels of cellular tryptase (> 10 ng/10(5) peripheral blood mononuclear cells/mL) and a tryptase/histamine (ng:ng) ratio greater than 1. The metachromatic cells expressed the mast-cell-related surface antigen c-kit, but not basophil-related antigens (CD11b, CDw17). Furthermore, in these 3 patients, spontaneous, MGF-independent growth of mast cells along with spontaneous synthesis of tryptase was demonstrable in long-term culture. No autocrine production, paracrine production, or overproduction of MGF was found. The spontaneous growth of mast cells could neither be abbrogated by addition of monoclonal antibodies (MoAbs) to c-kit nor by MoAbs against MGF (< 5% inhibition), whereas factor (MGF)-dependent differentiation of mast cells in these patients could be abbrogated by MoAbs to c-kit or MoAbs to MGF (> 70% inhibition, P < .001). In addition, serum MGF levels in these patients were within the normal range and MGF could not be detected in cell-free culture supernatants. All 3 patients showed rapid progression of disease and had a survival time of less than 1 year. In conclusion, we describe a unique form of transformation in MDS and CML-BC characterized by mast cell lineage involvement and factor-independent differentiation of mast cells. This form of leukemic transformation has to be delineated from chronic myeloid leukemia with basophilia or basophil crisis, from primary mast cell leukemia, and from monocytic leukemias and myelodysplastic disorders associated with basophilia.
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PMID:Kit ligand/mast cell growth factor-independent differentiation of mast cells in myelodysplasia and chronic myeloid leukemic blast crisis. 752 72

The term mastocytosis denotes a heterogeneous group of rare hematological disorders characterized by abnormal accumulation of mast cells. While cutaneous mastocytosis is relatively frequent mast cell leukemia belongs to the rarest forms of human leukemia. In the following we present the case of an aleukemic mast cell leukemia and shall discuss the revised classification of mastocytosis based on the "Year 2000 Working Conference on Mastocytosis" held in Vienna, Austria. A 48 year-old caucasian man presented with a four-week history of diarrhea, obstipation, vomiting, rash, and mild fever. Clinical inspection revealed a disseminated itching rash and a mild hepatomegaly. Red and white blood cell counts were within the normal range. Levels of the alkaline phosphatase and serum histamine were significantly increased. There was no splenomegaly or lymphadenopathy. Cytologic and histologic investigation of the bone marrow revealed a marked increase in atypical mast cells. Since only a few circulating mast cells could be detected in a cytospin preparation of the blood, the diagnosis of an aleukemic mast cell leukemia was established. About four weeks after the diagnosis had been established, the patient died with signs of a hemorrhagic shock due to a massive gastrointestinal bleeding. Autopsy revealed widespread mast cell infiltration of bone marrow, spleen, liver and lungs, but also a small, deeply penetrating, non-specific duodenal ulcer. In conclusion, despite of presentation with signs of a primary gastrointestinal disorder, the patient was found to suffer from an exceedingly rare aleukemic mast cell leukemia ("malignant mastocytosis") and died after a total duration of the disease of only about three months.
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PMID:[Aleukemic mast cell leukemia (formerly: "malignant mastocytosis"): an extremely rare form of leukemia. A case report and simultaneously a contribution to revised classification of mastocytosis]. 1223 4

Acquired mutations in KIT are driver mutations in systemic mastocytosis (SM). Here, we tested the role of SHP2/PTPN11 phosphatase in oncogenic KIT signaling using an aggressive SM mouse model. Stable knock-down (KD) of SHP2 led to impaired growth, colony formation, and increased rates of apoptosis in P815 cells. This correlated with defects in signaling to ERK/Bim, Btk, Lyn, and Stat5 pathways in P815-KD cells compared to non-targeting (NT). Retro-orbital injections of P815 NT cells in syngeneic DBA/2 mice resulted in rapid development of aggressive SM within 13-16 days characterized by splenomegaly, extramedullary hematopoiesis, and multifocal liver tumors. In contrast, mice injected with P815 SHP2 KD cells showed less disease burden, including normal spleen weight and cellularity, and significant reductions in mastocytoma cells in spleen, bone marrow, peripheral blood and liver compared to NT controls. Treatment of human mast cell leukemia HMC-1 cells or P815 cells with SHP2 inhibitor II-B08, resulted in reduced colony formation and cell viability. Combining II-B08 with multi-kinase inhibitor Dasatinib showed enhanced efficacy than either inhibitor alone in blocking cell growth pathways and cell viability. Taken together, these results identify SHP2 as a key effector of oncogenic KIT and a therapeutic target in aggressive SM.
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PMID:Oncogenic KIT-induced aggressive systemic mastocytosis requires SHP2/PTPN11 phosphatase for disease progression in mice. 2502 79