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)

While assessing the prognostic implications of immunophenotyping in 382 patients enrolled in treatment protocols of the Eastern Cooperative Oncology Group (ECOG) for de novo adult acute myeloid leukaemia, we identified 95 patients with a unique antigen profile characterized by high expression of the leucocyte integrin CD11b (CD11b+ AML). High expression of CD11b was defined as > or = 32% positive blasts based on the retrospectively established prognostic cut-off point for this antigen. Although CD11b is normally expressed by mature monocytes, natural killer cells and granulocytes, leukaemic blasts in CD11b+ AML lacked other immunologic monocytic features (e.g. CD14 and CD122, the interleukin-2 receptor beta chain) and demonstrated a high degree of immaturity, as reflected by a high incidence of blasts expressing the stem cell factor receptor, CD117, and few blasts positive for the myeloid differentiation antigen CD15. Furthermore, by FAB criteria, only 41% of CD11b+ AML cases were classified as M4/M5. Patients with CD11b+ AML had a low response rate (54%) when compared with acute monocytic leukaemia (AMOL; 82%, P = 0.006) or AML overall (68%, P = 0.031), independent of age, cytogenetic abnormalities and P-glycoprotein expression. Because of its poor prognosis, recognition of CD11b+ AML is clinically warranted and, given its morphologic and cytogenetic ambiguity, must be based on the unique antigen profile.
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PMID:Acute myeloid leukaemia expressing the leucocyte integrin CD11b-a new leukaemic syndrome with poor prognosis: result of an ECOG database analysis. Eastern Cooperative Oncology Group. 948 12

We previously reported a novel differentiation antigen, which is specifically expressed in stage II double positive (CD4+CD8+) human cortical thymocytes (Park et al, J Exp Med 1993; 178: 1447-1451). This study was designed to investigate the expression pattern of JL1 in various types of leukemic cells from patients and normal hematopoietic cells to evaluate the possibility as a tool for diagnosis and treatment of leukemia. The expression of JL1 antigen was observed in 75.6% of leukemic cases (117 out of 154 leukemic patients tested) on flow cytometric analysis. The percentage of JL1-positive cases of T lineage acute lymphoblastic leukemia (T-ALL) (92.6%) was higher than that of other types of leukemias (75%). The presence of JL1 antigen was also confirmed by immunoblotting and immunoprecipitation. Since the JL1 antigen is selectively expressed on the surface of human leukemic cells but not on the mature human peripheral blood cells, normal bone marrow cells and various types of normal tissues, JL1 could be an excellent candidate for an immunodiagnostic and immunotherapeutic tool for hematopoietic malignancies such as leukemia.
Leukemia 1998 Oct
PMID:A cell surface molecule, JL1; a specific target for diagnosis and treatment of leukemias. 976 3

Tumor-specific antigens for leukemia cells have been sought for the past decades, but none of cell surface markers met sufficient criteria as a 'phenotypic signature'. Here we suggest that JL1 antigen can be efficiently used for diagnosis and treatment. JL1 is a human thymocyte differentiation antigen strictly confined to a CD4+CD8+ double positive subpopulation of cortical thymocytes. Despite its restricted distribution in normal tissues and cells, the expression of JL1 is highly associated with hematopoietic malignancies, particularly various types of leukemia such as T-lineage acute lymphoblastic leukemia (T-ALL), non-T-ALL, and acute myelocytic leukemia (AML). The expression of JL1 antigen was observed in 75.6% of leukemic cases (117 out of 154 leukemic patients tested) with a high mean fluorescence intensity on flow cytometric analysis and confirmed by immunoblotting. Since JL1 antigen is selectively expressed on the surface of human leukemic cells, but not on mature human peripheral blood cells and normal bone marrow cells, anti-JL1 mAb can be used as a reagent of choice in the routine diagnosis of various types of leukemia, providing an excellent candidate for the treatment of these diseases.
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PMID:Immunotherapeutic potential of JL1, a thymocyte surface protein, for leukemia. 981 Nov 72

Sixteen patients with acute myeloid leukemia (AML) were treated with a continuous i.v. infusion of mAb PM-81, an IgM mAb directed against the cellular differentiation antigen CD15, which is expressed on leukemia cells of >95% of patients with AML. MAb PM-81, also referred to as MDX-11, is capable of activating human and rabbit complement and lysing CD15-positive AML cells. In this Phase I study, patients were treated with 0.5, 1.0, or 1.5 mg/kg MDX-11 delivered over a 24-h period followed by conventional chemotherapy. Transient decreases in circulating blast cells postinfusion (prior to chemotherapy) were observed at all doses. We were able to show MDX-11 binding to bone marrow blasts in those patients who achieved stable serum levels of MDX-11. Serum MDX-11 was detectable at the 1. 0- and 1.5-mg/kg doses. Doses of 0.5 and 1.0 mg/kg were generally well tolerated, with no toxicities greater than grade II (Eastern Cooperative Oncology Group) reported. However, two of five patients receiving the 1.5-mg/kg dose experienced grade IV toxicities that resolved with treatment (one of these patients completed the infusion). Common toxicities reported included fever, chills, and hypotension. Only one patient developed human antimouse antibodies at 4 weeks posttreatment. This study determined that 1.0 mg/kg is a biologically effective dose that can be administered safely with little toxicity. Based on these results, we are pursuing a Phase I/II study of MDX-11 infusion following chemotherapy for patients with relapsed AML.
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PMID:Phase I clinical trial of serotherapy in patients with acute myeloid leukemia with an immunoglobulin M monoclonal antibody to CD15. 981 68

To identify new markers of minimal residual disease (MRD) in B-lineage acute lymphoblastic leukemia (ALL), gene expression of leukemic cells obtained from 4 patients with newly diagnosed ALL was compared with that of normal CD19(+)CD10(+) B-cell progenitors obtained from 2 healthy donors. By cDNA array analysis, 334 of 4132 genes studied were expressed 1.5- to 5.8-fold higher in leukemic cells relative to both normal samples; 238 of these genes were also overexpressed in the leukemic cell line RS4;11. Nine genes were selected among the 274 overexpressed in at least 2 leukemic samples, and expression of the encoded proteins was measured by flow cytometry. Two proteins (caldesmon and myeloid nuclear differentiation antigen) were only weakly expressed in leukemic cells despite strong hybridization signals in the array. By contrast, 7 proteins (CD58, creatine kinase B, ninjurin1, Ref1, calpastatin, HDJ-2, and annexin VI) were expressed in B-lineage ALL cells at higher levels than in normal CD19(+)CD10(+) B-cell progenitors (P <.05 in all comparisons). CD58 was chosen for further analysis because of its abundant and prevalent overexpression. An anti-CD58 antibody identified residual leukemic cells (0.01% to 1.13%; median, 0.03%) in 9 of 104 bone marrow samples from children with ALL in clinical remission. MRD estimates by CD58 staining correlated well with those of polymerase chain reaction amplification of immunoglobulin genes. These results indicate that studies of gene expression with cDNA arrays can aid the discovery of leukemia markers. (Blood. 2001;97:2115-2120)
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PMID:Identification of novel markers for monitoring minimal residual disease in acute lymphoblastic leukemia. 1126 79

The identification of immunophenotypic markers with restricted expression has long been a critical issue in diagnostic and therapeutic advances for acute leukemias. We previously developed a monoclonal antibody against a new thymocyte surface antigen, JL1, and showed that JL1 is expressed in the majority of acute leukemia cases. In this study, using multiparameter flow cytometric analyses, we found that JL1 was uniquely expressed in subpopulations of normal bone marrow (BM) cells, implying the association of JL1 with the differentiation and maturation process. Although CD34(+) CD10(+) lymphoid precursors and some of maturing myeloid cells express JL1, neither CD34(+) CD38(-/lo) nor CD34(+) AC133(+) noncommitted pluripotent stem cells do. As for the myeloid precursors, CD34(+) CD33(+) cells do not express JL1. During lymphopoiesis, JL1 on the earliest lymphoid precursors disappear in the CD20(+) sIgM(+) stage of B-cell development or after CD1a down-regulation in thymocytes. Despite the highly restricted expression of JL1 in normal BM cells, most of the leukemias express JL1 irrespective of their immunophenotypes. These results indicate that JL1 is not only a novel differentiation antigen of hematopoietic cells, but also a leukemia-associated antigen. Therefore, we suggest that JL1 be a candidate molecule in acute leukemia for the diagnosis and immunotherapy that spares the normal BM stem cells.
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PMID:Expression of leukemia-associated antigen, JL1, in bone marrow and thymus. 1129 May 65

Somatic variants with constitutive changes in the expression of the cortical thymocyte differentiation antigen HTA 1 were derived from the T-cell leukemia line Molt 4 using monoclonal antibody NA1/34 and the fluorescent activated cell sorter. Cells with the highest and lowest fluorescence were sorted and expanded. After several cycles, high expressor variants, with 10- to 12-fold increased surface HTA 1 and low expressors, with a level of one third relative to the wild-type, were obtained. The stability of the high expressors was improved by cloning. In spite of the large differences in the level of HTA 1 between the various mutants and the wild-type, the expression of HLA-A,B,C or its increase following interferon-alpha stimulation, remained unchanged. Although in HTA 1 there was only a trace of beta2-microglobulin (beta2m) detected by lactoperoxidase labelling of the high expressor variants, significant levels of both beta2m and HTA 1 light chain beta(t) were observed in gels stained with Coomassie blue. The physiological association of beta(t) with HTA 1 was confirmed by the substantial increase of beta(t) which parallels the increase of HTA 1.
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PMID:Somatic variants of the level of expression of a cell surface antigen. 1189 17

CD20 is a B-cell differentiation antigen and known to induce apoptosis in Burkitt's lymphoma/leukemia (BL) cells upon antibody-mediated crosslinking. We examined the biological effect of CD20 crosslinking on BL cell lines and observed that apoptosis induction is accompanied by activation of multiple caspases, including caspase-8, -9, -3, -2, and -7. Further investigation revealed a clear synergism between apoptosis mediated by CD20 and by B-cell antigen receptor (BCR). Examination of the effect of simultaneous crosslinking of other cell surface molecules with crosslinking of CD20 or BCR on apoptosis induction showed that these molecules had either a synergistic or inhibitory effect on induction of apoptosis. It is worth noting that some molecules had a different effect on CD20- and BCR-mediated apoptosis. Simultaneous crosslinking of the molecules CD10, CD22, CD72, and CD80 inhibited BCR-mediated apoptosis, but enhanced CD20-mediated apoptosis. Further studies revealed that regulation of CD20-induced apoptosis by other costimulatory molecules is achieved by modification of caspase activation. CD20-mediated apoptosis in BL cells may provide not only a model for understanding the mechanism regulating clonal selection of B cells but a new therapeutic strategy for BL patients.
Leukemia 2003 Jun
PMID:Costimulatory signals distinctively affect CD20- and B-cell-antigen-receptor-mediated apoptosis in Burkitt's lymphoma/leukemia cells. 1276 85

While studying the unique Nramp1 (Slc11a1)-independent susceptibility to Mycobacterium bovis (BCG) infection of BXH-2 mice, we noted that these mice develop important splenomegaly and enlargement of lymph nodes. Segregation analyses in several F2 crosses showed that splenomegaly segregates as a single recessive trait caused by a novel mutation in BXH-2, independent of the infection. Histologic and fluorescence-activated cell sorter (FACS) analyses indicated that splenomegaly is associated with a large increase in Mac1+/GR1+ (macrophage antigen-1+/granulocyte differentiation antigen 1+) granulocyte precursors in spleen, lymph nodes, and bone marrow, resembling a myeloproliferative syndrome. This is concomitant to extramedullary erythropoiesis in the spleen, as measured by proportion of Ter119+ erythroid cells. The locus controlling this myeloproliferative syndrome and splenomegaly was designated Myls and maps to an 18 centimorgan (cM) region of chromosome 8, which also contains an integrated copy of an N-ecotropic murine leukemia virus (MuLV) provirus (Emv2). The relationship between Myls, expansion of Mac1+/GR1+ cells, and Emv2 was investigated. Homozygosity at Myls is necessary but not sufficient for B-ecotropic virus replication in splenocytes, the extent of which appears to be under separate genetic control. Our results suggest a model in which Myls-dependent myeloproliferation in BXH-2 acts as a predisposing factor for the subsequent development of virally induced myeloid leukemia characteristic of this strain.
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PMID:Genetic control of myeloproliferation in BXH-2 mice. 1463 Aug 19

The precise genetic events leading to myelodysplastic syndromes (MDSs) and leukemic transformation remain poorly defined. Even less is known about adult familial MDS. We report an adult MDS family in whom enriched tissue-specific transcripts were derived by subtractive hybridization of cDNA from the mononuclear and CD34+ cells of affected and unaffected family members. These expression libraries were then hybridized to Genome Discovery arrays containing 18 404 genes and expressed sequence tags, and several clusters of differentially expressed genes were identified. A group of 21 genes was underexpressed (>5-fold) in affected vs unaffected family members, and among these were transcription factors and genes involved in myeloid differentiation, such as ZNF140 and myeloid nuclear differentiation antigen (MNDA). Another group of 36 genes was overexpressed (>5-fold), and these encoded proteins belonging to signaling pathways, such as Ras- and Fos-related genes. The top two genes downregulated in this MDS family, ZNF140 and MNDA, were similarly altered in another MDS family, and in some cases of sporadic MDS. Our data suggest that we have identified genes differentially expressed in adult familial MDS, and that alteration of some of these genes may also be important for the evolution of different stages or severity of sporadic MDS.
Leukemia 2004 Mar
PMID:Differentially expressed genes in adult familial myelodysplastic syndromes. 1473 73


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