Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human tumor necrosis factor alpha (TNF-alpha) gene is one of the earliest genes transcribed after the stimulation of a B cell through its antigen receptor or via the CD-40 pathway. In both cases, induction of TNF-alpha gene transcription can be blocked by the immunosuppressants cyclosporin A and FK506, which suggested a role for the NFAT family of proteins in the regulation of the gene in B cells. Furthermore, in T cells, two molecules of NFATp bind to the TNF-alpha promoter element kappa 3 in association with ATF-2 and Jun proteins bound to an immediately adjacent cyclic AMP response element (CRE) site. Here, using the murine B-cell lymphoma cell line A20, we show that the TNF-alpha gene is regulated in a cell-type-specific manner. In A20 B cells, the TNF-alpha gene is not regulated by NFATp bound to the kappa 3 element. Instead, ATF-2 and Jun proteins bind to the composite kappa 3/CRE site and NFATp binds to a newly identified second NFAT site centered at -76 nucleotides relative to the TNF-alpha transcription start site. This new site plays a critical role in the calcium-mediated, cyclosporin A-sensitive induction of TNF-alpha in both A20 B cells and Ar-5 cells. Consistent with these results, quantitative DNase footprinting of the TNF-alpha promoter using increasing amounts of recombinant NFATp demonstrated that the -76 site binds to NFATp with a higher affinity than the kappa 3 site. Two other previously unrecognized NFATp-binding sites in the proximal TNF-alpha promoter were also identified by this analysis. Thus, through the differential use of the same promoter element, the composite kappa 3/CRE site, the TNF-alpha gene is regulated in a cell-type-specific manner in response to the same extracellular signal.
Mol Cell Biol 1996 Oct
PMID:Cell-type-specific regulation of the human tumor necrosis factor alpha gene in B cells and T cells by NFATp and ATF-2/JUN. 881 36

We have cloned the cDNA encoding the human ornithine decarboxylase antizyme from a 5'-stretch cDNA library of human B-cell lymphoma Daudi. The cloned human antizyme cDNA fragment consists of 1063 bp, has 80% homology to the rat antizyme cDNA, but shows almost no homology to the E. coli antizyme gene. Northern hybridization analysis shows that this gene is expressed in a number of human cell lines with an estimated mRNA transcript size of about 1.1 kb. The size of the mRNA suggests that the cloned cDNA fragment probably represents the full length of human antizyme mRNA transcript. Comparison of the human and rat antizymes demonstrates that they are highly conserved at both nucleotide and peptide levels.
Biochem Mol Biol Int 1996 Apr
PMID:Molcecular cloning of human antizyme cDNA. 913 64

Sixty malignant non-Hodgkin's lymphomas originating in the upper aerodigestive tract have been analyzed for their cytologic type, immunophenotype and association with the Epstein-Barr virus (EBV). The majority of these tumors were B-cell lymphomas of blastic cytology (78%) with the exception of lymphomas in the parotid gland. Large B-cell lymphomas were the most frequent encountered in the sinonasal region and Waldeyer's ring. Twelve lymphomas were of T- or T/NK (natural killer)-cell lineage. They were in the nasal cavity and the paranasal sinuses (4), the tonsil (5), and the oral cavity (3). Epstein-Barr sequences were detected in five angiocentric T/NK-lymphomas, one peripheral T-cell lymphoma, one lymphoma of lymphomatoid granulomatosis type, one large B-cell lymphoma, and in a lymphoroliferative disorder in an HIV-positive patient. These results suggest that EBV is not involved in lymphomagenesis of B-cell tumors, but is associated with angiocentric T/NK-cell lymphoma in the upper aerodigestive tract.
Diagn Mol Pathol 1997 Jun
PMID:The Epstein-Barr virus in malignant non-Hodgkin's lymphoma of the upper aerodigestive tract. 927 84

Three strategies were used to evaluate 38C13 B-cell lymphoma-specific idiotype immunization to protect against subsequent lymphoma challenge in C3H/He mice. It was observed that tumor-specific immunity could be induced by immunization with (i) KLH-conjugated 38C13 B-cell lymphoma idiotype in complete Freund's adjuvants (survival rate 80%), (ii) dendritic cells pulsed in vitro with native idiotype protein (survival rate 80%), and (iii) bispecific antibodies composed of B-lymphoma-related idiotype and an MHC class II binding moiety (survival rate 40%). Presentation of idiotype determinants by dendritic cells or bispecific antibody resulted in lymphoma-specific immunity and obviated the requirement for carrier protein or adjuvant. Moreover, primed dendritic cells induced predominant development of a tumor-specific T-cell response. Each of these immunization strategies resulted in long-term survival without the emergence of idiotype variants or the induction of tumor dormancy.
Cytokines Mol Ther 1996 Dec
PMID:Idiotype vaccination strategies against a murine B-cell lymphoma: dendritic cells loaded with idiotype and bispecific idiotype x anti-class II antibodies can protect against tumor growth. 938 9

BKS-2 is an immature B cell lymphoma that undergoes apoptotic cell death when signaled via its surface IgM receptor. To study the signaling components of surface IgM mediated apoptosis in B lymphoma cells, we generated mutants of BKS-2 that were resistant to anti-IgM induced apoptosis. One mutant cell line, 1.B5, did not undergo apoptotic cell death upon treatment with anti-IgM antibodies and also did not exhibit elevation of intracellular Ca2+ in response to cross-linking of surface IgM. This appeared to be due to a defect in protein tyrosine kinase (PTK) activity since fewer proteins were tyrosine phosphorylated in the mutant cells stimulated with anti-IgM when compared to wild type BKS-2. Subsequently, we showed that protein tyrosine kinases lyn and blk were inducibly tyrosine phosphorylated in the wild type BKS-2 but not in 1.B5 mutant cells in response to anti-IgM. Also the kinase activity of lyn was elevated in the wild type but not in mutant cells upon triggering through surface IgM. Furthermore, tyrosine phosphorylation of CD19, a known substrate of lyn, was inducible in anti-IgM stimulated BKS-2 cells but severely reduced in 1.B5 cells. In contrast, kinase activity of another src kinase, blk, was increased on anti-IgM stimulation in both wild type and mutant cells. Surprisingly, syk, a non-src protein tyrosine kinase important for surface IgM mediated signaling, was tyrosine phosphorylated in the lyn deficient mutant cells as well as in the wild type BKS-2 cells. Furthermore, anti-IgM induced increase in kinase activity of syk was similar in the mutant and wild type cells. Thus, in contrast to other studies that propose syk to be a downstream target of src family kinases, syk may act upstream of lyn in immature B cells. Consistent with a functional syk, its target, phospholipase gamma2 (PLC-gamma2) was normally tyrosine phosphorylated in mutant cells.
Mol Immunol
PMID:Activation of syk in an immature B cell line does not require lyn activity. 946 22

In the present study the changes in the detection rate of bcl-2 and IgH gene rearrangements in relation to chemotherapy and therapeutic response in patients with diffuse large B-cell lymphoma have been investigated. Immunoglobulin gene rearrangements were detected in almost all patients during all stages of treatment. Persistence of bcl-2 rearrangements reflected the effect of chemotherapy better. Bcl-2 rearrangements were initially detected in 64% of the patients. Cells bearing the translocation disappeared during therapy in a significant group of cases. In 10 patients bcl-2-rearranged cells were detected for varying periods of time. However, no correlation was found between the molecular persistence or disappearance of cells as detected by PCR and the therapeutic response or recurrence rates.
Res Commun Mol Pathol Pharmacol 1998 Jun
PMID:Investigation of the molecular changes during chemotherapy in non-Hodgkin's lymphoma. 973 9

The diagnosis of marrow involvement in non-Hodgkin's lymphoma (NHL) relies on morphology with support from immunophenotyping by flow cytometry (FCM). We assessed the relative sensitivity of morphology, FCM, and consensus primer polymerase chain reaction (PCR) of antigen receptor genes in the detection of marrow involvement. In 78 of 100 (78%) cases, there was concordance between FCM and PCR. FCM detected more cases of clonality in B-cell neoplasia. There were 40 cases with objective evidence of involvement by B-cell neoplasia. In this group, FCM had a sensitivity of 97.5% (39 of 40); PCR had a sensitivity of 67.5% (27 of 40). In contrast, PCR had a sensitivity of 71.4%, and FCM a sensitivity of 28.6%, in T-cell neoplasia. In all 12 cases with involvement detected by biopsy, there was objective evidence of clonality. However, clonality was detected in four of seven patients with chronic lymphocytic leukemia and in five of eight patients with T-cell neoplasia in the absence of morphologically detectable disease. Clonality was identified in only one of seven patients with B-cell lymphoma in which the biopsy was interpreted as "suspicious but not diagnostic of involvement." We conclude that morphology remains of central importance in the evaluation of marrow involvement in NHL. We show that FCM and PCR identify involvement in the absence of morphologically apparent disease. In B-cell neoplasms, FCM remains the method of choice for the detection of clonality. PCR for T-cell receptor gene rearrangements may be an important adjunct to the diagnosis of marrow involvement in patients with T-cell neoplasms.
Diagn Mol Pathol 1998 Apr
PMID:Morphologic, immunophenotypic, and molecular evaluation of bone marrow involvement in non-Hodgkin's lymphoma. 978 7

In fine needle aspiration biopsy (FNAB) of salivary gland delineation of low-grade B-cell lymphoma from benign lymphoid lesions of myoepithelial sialadenitis (MESA) may be very difficult by means of cytomorphological criteria alone. To improve cytodiagnosis PCR technique was applied on routinely stained smears to determine clonal status by amplifying the third complementarity-determining region (CDR3) of the hypervariable domain of the immunoglobulin heavy chain. Twelve cases diagnosed cytologically as suspicious of low-grade B-NHL with following histology of B-NHL (n = 5) or MESA (n = 7) were analyzed. The CDR3-IgH PCR produced distinct bands in 10/12 cases. The PCR products were analyzed with Genescan software on the DNA sequencer, which demonstrated monoclonal bands in all NHLs and in one case of MESA. The results indicate that PCR technique may be helpful in improving cytodiagnostic accuracy for recognition of low-grade B-NHL of salivary gland.
Int J Mol Med 1998 Sep
PMID:The value of PCR technique in fine needle aspiration biopsy of salivary gland for diagnosis of low-grade B-cell lymphoma. 985 8

The changes of phospholipase D (PLD) activity were investigated during the courses of apoptotic process induced by tumor necrosis factor (TNF)-alpha or anti-Fas/Apo1 antibody in human premyelocyte HL-60 and murine B cell lymphoma A20 cells. The treatment of recombinant TNF-alpha to HL-60 cells resulted in the increased PLD activity as determined by the phosphatidylethanol formation in the presence of 1% ethanol. The enhancement of PLD activity was also observed in the anti-Fas/Apo1 monoclonal antibody-treated A20 cells. However, the activity of PLD was maximized when HL-60 and A20 cells were treated with either TNF-alpha or anti-Fas/Apo1 monoclonal antibody for 6 h. Both TNF-alpha and anti-Fas/Apo1 monoclonal antibody increased PLD activity in a dose-dependent manner up to 200 U/ml and 200 ng/ml, respectively. When the intracellular activity of protein kinase C (PKC) was interrupted by treatment of calphostin-C, both the PLD activation and the apoptosis induced by TNF-alpha and anti-Fas/Apo1 monoclonal antibody appeared to be inhibited. Since PKC is reported to activate PLD, the results indicate that the intracellular signaling cascade via PLD may play a role in the induction of apoptosis induced by TNF-alpha and anti-Fas/Apo1 monoclonal antibody.
Exp Mol Med 1998 Mar 31
PMID:Changes of phospholipase D activity in TNF-alpha and anti-Fas/Apo1 monoclonal antibody induced apoptosis in HL-60 and A20 cells. 987 18

Increasing evidence suggests that chemotherapy does not cure the majority of patients with B cell non-Hodgkin's lymphoma (NHL). Therefore new treatment modalities are necessary. Immunotherapy of B cell lymphomas using monoclonal antibodies has been shown to be efficacious in murine model systems and also in patients. With the identification of tumor-specific antigens as targets for autologous T cells, T cell mediated immunity has been revived as an immunotherapeutic modality in B cell lymphomas. For B cell lymphomas the lymphoma-specific idiotype can be used as a tumor-specific antigen to stimulate T cells. Alternatively, the malignant B cells can be modified to become efficient antigen-presenting cells and present peptides from their own tumor-specific antigens to the autologous T cells. Here we discuss previous and currently explored immunotherapeutic strategies for B cell lymphoma.
J Mol Med (Berl) 1999 Mar
PMID:T cell mediated immunotherapy for B cell lymphoma. 1009 May 95


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