Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q06643 (non-Hodgkin's lymphoma)
 11,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Murine monoclonal antibody (mAb) 7C11 binds to the same cell surface epitope as anti-APO-1 and anti-Fas and reacts specifically with cells transfected with a cDNA encoding the human Fas antigen. Furthermore, incubation with 7C11 causes death of hematopoietic cell lines that express APO-1/Fas but not APO-1/Fas-negative cell lines. 7C11 therefore recognizes the human APO-1/Fas (CD95) antigen, a 40 to 50 kDa cell surface glycoprotein that can trigger apoptosis or programmed cell death. Expression of APO-1/Fas antigen by normal and neoplastic hematopoietic cells was determined by flow cytometry using 7C11. APO-1/Fas is expressed by approximately 30 to 40% of resting peripheral blood T cells, B cells, and monocytes and by approximately 5% of resting NK cells and thymocytes. It was not detected on granulocytes, erythrocytes, or platelets. Approximately 80 to 90% of activated T cells, B cells, and thymocytes express APO-1/Fas, as do the majority of activated NK cells. Perturbation of APO-1/Fas by 7C11 does not affect the viability of resting lymphocytes or monocytes. In contrast, activated T cells and NK cells undergo apoptosis within 3 hours of exposure to 7C11. Other mAb that stimulate T cells or NK cells do not cause rapid induction of programmed cell death. APO-1/Fas antigen is expressed by many cell lines of lymphoid and myeloid lineage. However, this antigen was detected on neoplastic cells from only one of 69 patients with acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, or multiple myeloma. Only 3 out of 25 tumor samples from patients with non-Hodgkin's lymphoma were found to express APO-1/Fas. All three of these lymphomas harbored the bcl-2-Ig fusion gene associated with the chromosomal translocation t (14;18). Conversely, only 27% of lymphomas that possessed the bcl-2-Ig gene were found to express the APO-1/Fas antigen. Like normal activated lymphocytes, leukemia and lymphoma cells that expressed APO-1/Fas antigen were found to undergo apoptosis in vitro after incubation with 7C11. The APO-1/Fas antigen appears to regulate the growth of normal hematopoietic cells, and the marked upregulation of this antigen on activated normal lymphocytes contrasts sharply with the absence of APO-1/Fas on neoplastic cells of hematopoietic lineage. Defects in the apoptotic signal delivered through this antigen might contribute to the pathogenesis of hematopoietic neoplasms. Thus, the gene encoding APO-1/Fas can be considered a novel type of tumor suppressor gene, just as bcl-2 can be considered a cellular proto-oncogene.
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PMID:Functional consequences of APO-1/Fas (CD95) antigen expression by normal and neoplastic hematopoietic cells. 753 60

Members of the TNF receptor superfamily are type I membrane glycoproteins with limited homology (overall homologies: 25%-30%) in the extracellular domain containing variable numbers of cysteine-rich repeats. In contrast, the TNF ligand superfamily members (with the exception of LT-alpha) are type II membrane glycoproteins with limited homology to TNF (overall homologies: 20%) in the extracellular region. TNF and LT-alpha are trimeric proteins and are composed of beta-strands forming a beta-jellyroll, the homology of the beta-strand regions for the TNF ligand superfamily members suggests a similar trimeric or multimeric complex formation for the other members. A genetic linkage, as evidence for evolutionary relatedness, is also found by chromosomal cluster for CD30, CD120b, 4-1BB and OX40 to 1p36; CD27, CD120a and TNFR-RP to 12p13; TNF, LT-alpha and LT-beta to 6p21; CD27L and 4-1BBL to 19p13; CD95L and OX40L to 1q25. TNF, LT-alpha and LT-beta and their receptors (CD120a, CD120b, TNFR-RP) interact in a complex fashion. Other family members, however, show a one ligand/one receptor binding principle. Signals can also be transduced through at least some of the ligands. TNF superfamily ligands are involved in induction of cytokine secretion, upregulation of adhesion molecules, activation antigens and costimulatory proteins, all known to amplify stimulatory and regulatory signals that occur during immune responses. On the other hand, differences in the distribution, kinetics of induction and requirements for induction support the view of a defined role for each of the ligands for T-cell-mediated immune activities. The shedding of members of the TNF receptor superfamily could limit the signals mediated by the corresponding ligands, as a functional regulatory mechanism. Induction of cytotoxic cell death is another common functional feature of this cytokine family (TNF, LT-alpha, CD30L, CD95L and 4-1BBL). Further studies have to identify unique versus redundant biological and physiological functions for each of the TNF superfamily ligands. In addition to other cytokines primary H-RS cell frequently express at least TNF, LT-alpha, CD27L and CD30L, but not CD40L. Furthermore, H-RS cells express several TNF receptors, such as CD30, CD40, CD95, CD120a, CD120b and 4-1BB. The TNF-like ligands might support growth and activation of HD-associated tumor cells and/or interact with surrounding reactive bystander cells, particularly T-cells. The different interactions between H-RS cells and surrounding reactive bystander cells are part of the pathobiology of HD. Detailed functional analysis have to confirm the predicted biological activities of TNF, LT-alpha, CD27L, CD30L, CD40L, CD95L, 4-1BBL and gp34/OX40L for the H-RS cell/T-cell interactions with impact on tumor growth and pathogenesis of HD. TNF and LT-alpha/CD120a and CD120b, CD30/CD30L, and CD40/CD40L are clearly critical elements in the deregulated network of interactive signals between H-RS cells and surrounding bystander cells with membrane-associated and cytokine-mediated events. Several TNFR superfamily members are also candidates for novel treatment protocols, including CD30 and CD40.
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PMID:Structural and biological features of the TNF receptor and TNF ligand superfamilies: interactive signals in the pathobiology of Hodgkin's disease. 883 4

Ligation of CD40 inhibits apoptosis and stimulates proliferation of normal B cells, whereas ligation of CD95 (APO-1/Fas) induces apoptosis of activated lymphocytes. Aberrant signalling through the CD40 and CD95 antigens could thus participate in the pathogenesis of lymphoid malignancies. The expression and function of CD40 and CD95 on neoplastic B cells from patients with acute lymphoblastic leukaemia (ALL), chronic lymphocytic leukaemia (CLL) and non-Hodgkin's lymphoma (NHL) were examined. CD40 was expressed by all 30 B-cell tumours, whereas CD95 was detected on neoplastic B cells in only one of 10 cases of ALL, two of 10 cases of CLL, and three of 10 cases of NHL. Incubation with an agonistic CD95 monoclonal antibody (MoAb) did not augment apoptosis in any of the unstimulated B-cell neoplasms. CD40 triggering did not consistently inhibit spontaneous apoptosis, but ultimately stimulated the growth of neoplastic B cells in most cases. Furthermore, CD40 activation led to up-regulation of the CD95 antigen in all 30 B-cell neoplasms. Ligation of CD95 on CD40-activated tumour cells augmented apoptosis in five of 10 ALL, three of 10 CLL, and nine of 10 NHL cases. The degree of apoptosis induced by CD95 triggering was greater for NHL cells than for ALL cells or CLL cells. Bcl-2 expression by ALL and NHL cells was substantially decreased after in vitro culture, whereas Bcl-2 expression by CLL cells was not significantly changed. However, there was no correlation between the level of Bcl-2 expression and sensitivity to CD95-mediated apoptosis. Thus, factors other than levels of CD95 and Bcl-2 determine susceptibility of malignant B cells to apoptosis after CD95 triggering. CD40-activated lymphoma cells appear to be very sensitive to CD95-mediated apoptosis, suggesting potential strategies for treatment of NHL. Elucidation of the mechanisms underlying resistance of ALL and CLL cells to CD95 triggering may facilitate the development of novel therapeutic approaches to these diseases as well.
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PMID:Role of the CD40 and CD95 (APO-1/Fas) antigens in the apoptosis of human B-cell malignancies. 916 8

Apoptosis mediated by the CD95 (Fas/Apo-1) molecule plays a crucial role in the regulation of the B-cell immune response. In this study, we examined the function of the CD95 antigen in B-cell-derived non-Hodgkin's lymphoma (NHL), a malignant disease of mature B cells. Membrane CD95 molecules were found to be constitutively expressed in a large number of NHL, including mantle cell (MCL, n = 10), lymphocytic (LCL, n = 10), follicular (FL, n = 11), and diffuse large cell lymphoma (DLCL, n = 9) with, however, different levels of intensity. Indeed, the levels of CD95 were low in MCL and LCL as compared with FL and DLCL. However, regardless of the intensity of expression, CD95 triggering with anti-CD95 monoclonal antibody (MoAb) did not induce apoptosis of lymphoma B cells, while these cells underwent apoptosis after irradiation or staurosporine treatment. Further experiments were then performed to address whether apoptosis could be restored by B-cell activation via CD40 cross-linking. We showed that CD40 engagement in the presence of interleukin (IL)-4 was more effective than CD40 engagement alone in upregulating the CD95 antigen and induced CD95-mediated cell death in nontumoral B cells. Concerning malignant B cells, CD40 ligation in the presence of IL-4 strongly increased CD95 expression, but did not markedly increase CD95-induced apoptosis. Furthermore, using cytotoxic T cells, we showed that CD95L was also ineffective in inducing apoptosis in lymphoma B cells, whereas these cells were killed by the perforin pathway. Our findings suggest that the CD95-mediated cell death pathway is altered in malignant cells from the NHL we tested. This could be a mechanism allowing lymphoma B cells to escape from immune regulation.
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PMID:Tumor B cells from non-Hodgkin's lymphoma are resistant to CD95 (Fas/Apo-1)-mediated apoptosis. 953 98

The Fas receptor (APO-1/CD95) is capable of inducing apoptosis of lymphoid cells and is expressed in some non-Hodgkin's lymphomas (NHLs). Fas expression is up-regulated at the surface of normal B cells upon triggering of the CD40 receptor. In this report, we investigated the sensitivity of NHLs to Fas-mediated apoptosis induced by anti-Fas monoclonal antibodies (MAbs) and its possible modulation by CD40 ligation in 18 NHL biopsy samples of various histological subtypes. Flow cytometric analysis showed that the fraction of Fas-expressing lymphoma cells was highly variable from sample to sample (from 1% to 93%, mean value 46%). The frequency of apoptotic cells was not significantly increased upon treatment with an anti-Fas MAb compared with control MAb in the 18 NHL cases analysed. The sensitivity of lymphoma cells to Fas-mediated apoptosis was correlated neither with the histological subtypes nor with the level of Fas expression. Activation of neoplastic B cells by CD40 ligation resulted in significant increases in Fas expression and Fas-induced apoptosis among the five B-NHL cases tested. The overall increase in apoptotic rates was moderate and remained lower in tumour samples than in control CD40-activated normal tonsil B cells. Altogether, our results indicate that the sensitivity to Fas-induced apoptosis is null or weak in NHL cells, irrespective of their histological subtype, and that it can be increased to a moderate and variable degree by CD40 ligation on neoplastic B cells. This may be an impediment to the development of Fas-based therapies for NHLs.
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PMID:Sensitivity to Fas-mediated apoptosis is null or weak in B-cell non-Hodgkin's lymphomas and is moderately increased by CD40 ligation. 968 98

Fas (APO-1/CD95) is a cell-surface receptor involved in cell death signaling. Germline mutations in the Fas gene have been associated with autoimmune lymphoproliferative syndrome, and somatic Fas mutations have been found in multiple myeloma. We have examined the entire coding region and all splice sites of the Fas gene in 150 cases of non-Hodgkin's lymphoma. Overall, mutations were identified in 16 of the tumors (11%). Missense mutations within the death domain of the receptor were associated with retention of the wild-type allele, indicating a dominant-negative mechanism, whereas missense mutations outside the death domain were associated with allelic loss. Fas mutations were identified in 3 (60%) MALT-type lymphomas, 9 (21%) diffuse large B-cell lymphomas, 2 (6%) follicle center cell lymphomas, 1 (50%) anaplastic large cell lymphoma, and 1 unusual case of B-cell chronic lymphocytic leukemia with a marked tropism for skin. Among the 16 patients with somatic Fas mutations, 15 showed extranodal disease at presentation, and 6 relapsed in extranodal areas. Ten of 13 evaluable patients showed features suggestive of autoreactive disease. Our data indicate that somatic disruption of Fas may play a role in the pathogenesis of some lymphomas, and suggest a link between Fas mutation, cancer and autoimmunity.
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PMID:Somatic Fas mutations in non-Hodgkin's lymphoma: association with extranodal disease and autoimmunity. 978 34

Four members of the tumor necrosis factor (TNF) ligand family, TNF-alpha, LT-alpha, LT-beta, and LIGHT, interact with four receptors of the TNF/nerve growth factor family, the p55 TNF receptor (CD120a), the p75 TNF receptor (CD120b), the lymphotoxin beta receptor (LT beta R), and herpes virus entry mediator (HVEM) to control a wide range of innate and adaptive immune response functions. Of these, the most thoroughly studied are cell death induction and regulation of the inflammatory process. Fas/Apo1 (CD95), a receptor of the TNF receptor family activated by a distinct ligand, induces death in cells through mechanisms shared with CD120a. The last four years have seen a proliferation in knowledge of the proteins participating in the signaling by the TNF system and CD95. The downstream signaling molecules identified so far--caspases, phospholipases, the three known mitogen activated protein (MAP) kinase pathways, and the NF-kappa B activation cascade--mediate the effects of other inducers as well. However, the molecules that initiate these signaling events, including the death domain- and TNF receptor associated factor (TRAF) domain-containing adapter proteins and the signaling enzymes associated with them, are largely unique to the TNF/nerve growth factor receptor family.
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PMID:Tumor necrosis factor receptor and Fas signaling mechanisms. 1035 62

We have studied tissue expression of the cytokine receptors using a high sensitivity biotin-streptavidin system on cryostat sections. We used a panel of monoclonal antibodies from the 6th International Workshop on Human Leukocyte Differentiation Antigens, namely CD25 (IL-2R alpha), CD95 (FAS antigen), CD116 (GM CSFR), CD117 (SCFR), CD120 alpha (TNFR I), CD120b (TNFR II), CD121a (IL-1R I), CDw123 (IL-3R), CD124 (IL-4R), CD126 (IL-6R), CD127 (IL-7R), CDw128 (IL-8R), CD130 (gpl130), CD131 (IL-3R), CD132 (IL-2R gamma), CD134 (OC-40), CD135 (FLT3/FLK2). Examined tissues (lymph nodes and spleens) were obtained from 12 patients with folicular non-Hodgkin's lymphoma, periferal T non-Hodgkin's lymphoma, B lymphoma, myeloma, Hodgkin's disease, two cases of T cell rich B-lymphoma, autoimmune haemolytic anemia and two cases of rudimentary trombocytopenic purpura. Our results indicate that immunohistological technology using native tissues on cryostat sections, monoclonal antibodies and the visualisation with biotin-streptavidin is a particularly suitable supplementary staining procedure for detection of the cytokine receptors in tissues.
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PMID:[Immunohistochemical detection of cytokine receptors on cryostat tissue sections]. 1037 62

T cell receptor, accessory molecules, cytokines are important regulatory factors that determine the development and function of T lymphocytes. Among them are also molecules belonging to superfamily of tumor necrosis factor receptor (TNFR) which beside CD30 include CD27, CD40, TNFR-I and -II, Fas (CD95), OX40, 4-1BB (CDw137), nerve growth factor receptor, lymphotoxin-beta receptor, Apo3/DR3/Ws1-1/lymphocyte associated receptor of death, DR4, DR5/TNF-related apoptosis-inducing ligand, osteoprotegerin, and TNFR-related 2. CD30 recognized originally on Reed-Sternberg cells of Hodgkin's lymphoma became of interest in studies of Th1 and Th2 cell differentiation. This paper shows recent findings regarding CD30 expression and its pleiotropic role in T cell function. It provides information about controversial role of CD30 as Th2 cell differentiation marker and gives concise insight into the function of this receptor as a signal transducing molecule.
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PMID:Expression and function of CD30 on T lymphocytes. 1048 69

CD95 (Fas/Apo-1) is a transmembrane molecule that induces apoptosis and plays a central role in the regulation of the immune response. The present study describes two new B lymphoid cell lines, B593 and BR97, derived from non-Hodgkin's lymphoma, which differ in susceptibility to CD95-mediated apoptosis. While B593 cells are sensitive to CD95mediated apoptosis, BR97 cells are completely resistant. Activation of caspase-8 and caspase-3 proteases plays an important role in the CD95 signalling pathway. CD95 stimulation induced caspase-8 and caspase-3 activation in B593, but not in BR97 cells. However, activation of both caspase-8 and caspase-3 was achieved in BR97 cells treated with staurosporine. Furthermore, protein synthesis inhibition by cycloheximide restored sensitivity to CD95-mediated apoptosis and allowed activation of both caspase-8 and caspase-3 in BR97 cells. These results indicate that, in BR97 cells, both caspases are functional and suggest that CD95-apoptosis resistance may result from the presence of inhibitory factor(s). Constitutive high level expression of the apoptotic inhibitor c-FLIP was observed in the CD95-resistant BR97 cell line compared to B593. Moreover, downregulation of c-FLIP expression level by protein synthesis inhibition strictly correlated with restored sensitivity to CD95-mediated apoptosis in BR97 cells. Furthermore, we demonstrate that c-FLIP is recruited to the CD95 DISC in BR97 cells together with caspase-8 and FADD. The data presented in this study strongly suggests that, in a B-NHL-derived cell line, resistance to CD95-mediated apoptosis results from endogenous high level expression of apoptotic inhibitor c-FLIP.
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PMID:Resistance to CD95-mediated apoptosis through constitutive c-FLIP expression in a non-Hodgkin's lymphoma B cell line. 1118 5


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