Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Collateral resistance to cisplatin and methotrexate has been reported in several cell lines. A murine leukemia cell line (L1210/DDP) selected for cisplatin resistance also has been shown to be highly resistant to methotrexate. Of the mechanisms proposed for methotrexate resistance, only changes in methotrexate transport into the cells were found in an earlier report. Methotrexate enters mammalian cells via an active transport system. In the present study, we demonstrated that the transport into the cell may be impaired in the resistant cells due to altered tyrosine phosphorylation of a membrane protein with a molecular mass of 66 kDa. This alteration was manifested by altered tyrosine phosphorylation of the 66 kDa protein and may be an underlying modification that renders the cells resistant to methotrexate. These results suggest involvement of tyrosine phosphorylation in folate transport and methotrexate resistant in L1210/DDP cells.
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PMID:Correlation of altered tyrosine phosphorylation with methotrexate resistance in a cisplatin-resistant subline of L1210 cells. 861 93

A novel cellular gene termed SFA-1 was isolated by differential hybridization of a cDNA library, using probes obtained from an adult T-cell leukemia cell line in comparison with probes obtained from normal CD4+ T cells and the MOLT-4 cell line. The mRNA of the SFA-1 gene is approximately 1.6 kb in size and encodes a protein of 253 amino acids, containing four putative transmembrane domains, a number of cysteine residues, and one potential N-glycosylation site in a major hydrophilic region between the third and fourth transmembrane domains. Expression of the SFA-1 gene was either absent or present at a low level in lymphoid cells but was up-regulated after transformation by human T-cell leukemia virus type 1 and transactivated by Tax. SFA-1 was broadly expressed in many human cell types and conserved in different species. Computer-aided comparison showed that SFA-1 had significant sequence homology and common structural features with members of the transmembrane 4 superfamily. SFA-1 antigen was detected as a 29-kDa membrane protein by immunoblotting, using anti-SFA-1 monoclonal antibody.
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PMID:SFA-1, a novel cellular gene induced by human T-cell leukemia virus type 1, is a member of the transmembrane 4 superfamily. 862 8

We studied the expression of the immunoglobulin-associated membrane protein B29 in 499 cases of chronic B cell diseases using the monoclonal antibody SN8 (CD79b). SN8 was positive in 5% (17/330) of chronic lymphocytic leukemia (CLL) and 100% (15/15) of B prolymphocytic leukemia. The expression of B29 in other B cell disorders was, as a rule, significantly higher than in CLL. Two thirds of non-Hodgkin's lymphomas in leukemic phase were SN8 positive, including lymphoplasmacytic (45%), follicular (83%), mantle cell (92%) and splenic lymphoma with villous lymphocytes (74%) while only 25% of hairy cell leukemias were SN8 positive. Within CLL, 2.3% of typical cases were SN8+ while 16% of cases with atypical morphology and an increased number of prolymphocytes were SN8+. Our results suggest a useful role for SN8 in the immunophenotypic differentiation of B cell disorders as a marker for non-CLL diseases. The analysis of B29 expression may throw light into the structure of the B cell antigen receptor in B cell malignancies while the distinctive reactivity profile of SN8 has direct applications to diagnosis.
Leukemia 1996 Dec
PMID:Expression of the immunoglobulin-associated protein B29 in B cell disorders with the monoclonal antibody SN8 (CD79b). 894 38

Osteopetrosis, a skeletal disorder of inadequate bone resorption with an abnormal increase in skeletal mass, results from a variety of independent single gene mutations that affect osteoclast differentiation and/or function. The osteopetrotic defect, op, is one of four spontaneous, nonallelic mutations in rats that result in osteopetrosis. In intercross progeny of (BN/SsN x LEW/SsN. +/op) F1 carriers, we mapped this locus by linkage analysis with microsatellite markers to rat chromosome 10. The linkage group contained, as well as op, 15 anonymous DNA loci and 9 DNA loci associated with genes (interleukin-3, myosin heavy chain [skeletal, embryonic], asialoglycoprotein receptor [hepatic lectin]-1, vesicle-associated membrane protein [synaptobrevin-2], sex hormone binding globulin, aldolase C, nitric oxide synthase [inducible], erythroblastic leukemia avian viral oncogene homolog-2, and proline-rich protein). The markers for these loci include nine not previously reported. The op locus mapped to the end of the chromosome 10 linkage group, within 1 cM of the anonymous DNA locus, D10Mit6. Based on its location, the op gene is likely to be distinct from seven described mutations in mice as well as three other mutations in rats. These results may permit a positional cloning strategy to be undertaken to identify the gene and mutation underlying the op defect.
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PMID:Localization of the gene responsible for the op (osteopetrotic) defect in rats on chromosome 10. 897 Aug 86

YU-311 is a monoclonal antibody reacting with cytosine arabinoside (AraC)-resistant human leukemic cell line and identifies a 92 kDa membrane protein. We have examined YU-311 reactivity with various hematopoietic disorders by an immunohistochemical method and evaluated a correlation between YU-311 expression and refractoriness to chemotherapy, retrospectively. YU-311 reacted with AraC-resistant human leukemia cell lines, in which a 92 kDa membrane protein was identified by Western blotting, whereas drug-resistant cell lines to other than AraC failed to express YU-311 antigen. The frequency of YU-311 positivity was significantly increased in relapsed cases. Only five cases were positive for YU-311 at diagnosis and 24 cases at relapse. Unexpectedly, only eight cases of relapsed leukemia/lymphoma expressed YU-311 and P-glycoprotein simultaneously. Most of the YU-311-positive relapsed cases showed clinical refractoriness for chemotherapy and then failed to induct complete remission or relapsed at short periods with short disease-free duration. These findings indicate that YU-311 expression is closely associated with some aspects of drug resistance, especially with AraC resistance.
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PMID:Reactivity of anti-AraC-resistant cell monoclonal antibody, YU-311, in formalin-fixed paraffin-embedded specimens of various hematopoietic disorders. 900 54

A family of cytokines [IL-6, IL-11, oncostatin M (OM), leukaemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF) and cardiotrophin-1] involved in various inflammatory or tumoral diseases share the same gp130 signal transducer chain. The complex formed with their specific receptors associates with a common transducing gp130 membrane protein (gp130) resulting in the formation of high avidity receptor and activation of tyrosine kinases. With the view of identifying gp130 domains specifically involved in IL-6 signalling, the authors prepared 37 new anti-gp130 mAb and analysed the structure-function relationship of the molecule. By cross-competition ELISA, the mAb were classified in 10 subgroups called A to J. By ELISA and BIAcore analysis, the mAb were found to recognize at least 18 antigenic specificities of the gp130 chain. The mAb reacted against the soluble and the membrane forms of gp130 as well. Their ability to inhibit the proliferation of the human myeloma cell line XG-4 of which the growth is strictly dependent on the presence of either exogenous IL-6, or LIF, or OM, or CNTF was studied. Besides mAb with no evident neutralizing effect (G and H) and mAb which neutralized equally well the activity of all tested cytokines (all mAb of groups A, I and J), some showed a selective effect. Those of group F inhibited also the proliferation induced by the 4 cytokines, but more specifically that dependent on the CNTF. mAb of groups B and E specifically inhibited the growth induced by IL-6, whereas those of group C inhibited that induced by LIF and OM. These results show the presence of different gp130 epitopes specifically involved in the signaling induced by the cytokines of the gp130 family. In ELISA, only mAb of group B and E were found to inhibit the binding of the IL-6-IL-6R complex to gp130, showing that they identified one or two domains of gp130 involved in its interaction with the IL-6-IL-6R complex. Precise identification of this(ese) epitope(s) would be useful to better understand the mechanisms of the IL-6 signalling.
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PMID:Specific inhibition of IL-6 signalling with monoclonal antibodies against the gp130 receptor. 911 31

Three adult patients with chronic active Epstein-Barr virus infection (CAEBV) had high anti-EBV-VCA antibody, positive anti-EA, low anti-EBNA and were associated with systemic lymphadenopathies and immunosuppression. The case 1 and 2 had elevated serum immunoglobulin levels, and recurrent infections, and case 3 showed pancytopenia. These 3 cases developed both EBV and latent membrane protein (LMP) positive malignant histiocytosis, EBV positive but LMP negative plasmacytoma, and EBV negative acute myelogeneous leukemia, respectively. It was suggested that CAEBV belonged to high risk groups for the development of malignant neoplasms. Since HLA of the case 1 and his father was identical, we conducted a in vitro cytotoxicity test using EBV transformed autologous B lymphocytes, K562 cells, and Raji cells to clarify the association of immunosuppression and HLA. The case 1 showed a low level of specific cytotoxicity to autologous EBV transformed B cells, while his parents were negative for the specific cytotoxicity. The patient and his parents developed inducible cytotoxicity to all targets after in vitro incubation of peripheral mononuclear cells with recombinant interleukin 2 (rIL-2) for 7 days. The patient and his mother showed lower enhancement of cytotoxicity, while HLA identical father could induce good cytotoxic activity to all targets as well as normal controls, indicating that a low IL-2 induced cytotoxic activity observed in CAEBV was independent of HLA associated immunoregulation at least in the case 1. Further studies are required to clarify the exact mechanisms responsible for the development of CAEBV.
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PMID:[Immunodeficiency and carcinogenesis in patients with chronic active Epstein-Barr virus infection]. 913 29

Multidrug resistance (MDR) is characterized by a decrease in the efficiency of chemotherapeutic agents correlated with the expression and activity of a membrane protein: the permeability-glycoprotein (Pgp 170). Clinically, detection of MDR can be performed by functional tests based on the accumulation of fluorescent compounds such as rhodamine 123. With the aim of improving the sensitivity of such analysis, we have evaluated JC-1, a fluorescent lipophilic carbocyanine dye. Above a critical concentration, JC-1 aggregates in a 'liquid crystal' form. Aggregates display a specific red emission band centered at 597 nm whereas the monomers display a green emission band centered at 540 nm. JC-1 was avidly accumulated in sensitive K562 cells where it displayed both a green cytoplasmic and red mitochondrial fluorescence. In contrast, JC-1 was poorly accumulated in resistant K562 cells, which displayed only a slight green fluorescence. The level of JC-1 accumulation was correlated with the level of Pgp expression detected by MRK16 and UIC2 antibodies on a set of K562 subclones with increasing resistance levels. The specific fluorescence properties of JC-1 allow accurate discrimination between low-level resistant cells and sensitive cells. Chemosensitizers such as verapamil, cyclosporine A or S9788 restored JC-1 accumulation in resistant cells. The fluorescence properties of JC-1 could therefore be used for monitoring the effects of reversing agents.
Leukemia 1997 Jul
PMID:Functional assay of multidrug resistant cells using JC-1, a carbocyanine fluorescent probe. 920 4

Erythropoiesis is regulated by erythropoietin and microenvironment of erythropoietic organs such as fetal liver and spleen in mice. We developed in vitro erythropoietic microenvironment by established stromal cell lines from erythropoietic organs, in which proliferation and differentiation of erythroid progenitor cells are supported by direct cell-to-cell contact between erythroid progenitor cells and the stroma cells. To identify the functional molecules of the stromal cells, we established monoclonal antibodies which detected specific molecules of the erythropoietic organs. Among those monoclonal antibodies, 11 D exhibited specific immunohistochemical staining of the red pulp of spleen where erythropoiesis dominates. Using this monoclonal antibody, we cloned a new gene (SMAP-1) which codes a type-II membrane protein. Over expression of its antisense cDNA in a stroma cell line caused a decrease in the erythropoietic supporting activity. Thus, SMAP-1 may play an important role in the erythropoietic stimulatory activity of the stromal cells.
Leukemia 1997 Apr
PMID:A new type-II membrane protein in erythropoietic organs enhances erythropoiesis. 920 33

YU-311 is a monoclonal antibody that reacts with a human leukemia cell line resistant for cytosine arabinoside and that identifies a 92 kDa membrane protein. The reactivity of YU-311 in normal organs, various non-hematopoietic tumors and in mast cell tumors in formalin-fixed, paraffin-embedded specimens was examined using immunohistochemical methods. In normal organs, YU-311 reacted with fundic glands of the stomach, the intercalated duct of the pancreas, the distal portion and the loop of Henle of renal tubules and tissue mast cells. Benign neoplasms of various organs showed no immunoreaction with YU-311, except for mast cell tumors. Some types of malignant neoplasms were occasionally positive against YU-311, suggesting neoplasms arising from or differentiating along normal YU-311-positive counterparts. Some other types of malignancies were rarely positive for YU-311, although their normal counterparts showed no immunoreactivity with YU-311. None of the non-epithelial tumors reacted with YU-311, except for one case of malignant melanoma. In contrast, normal tissue mast cells and their related tumors, such as urticaria pigmentosa or solitary mastocytoma, were constantly positive for YU-311. None of the non-hematopoietic human tumor cell lines examined in the present study was reactive with YU-311. These findings indicate that YU-311 is a good marker of some types of tumors and mast cell tumors and that an aberrant expression of YU-311 rarely occurs.
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PMID:Reactivity of antibody YU-311 in formalin-fixed, paraffin-embedded specimens of normal organs, non-hematopoietic tumors, and mast cell tumors. 929 30


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