Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019829 (Hodgkin's disease)
 30,247 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among the systems triggering apoptosis, the Fas-Fas ligand (FasL) system is recognized as a major pathway for the induction of apoptosis in cells and tissues. Ligation of Fas by either an agonistic antibody or FasL transmits a 'death signal' to the target cell, potentially triggering apoptosis. Alterations of genes along the Fas-mediated apoptosis pathway have been reported in many human cancers. However, there have been no data regarding FasL gene mutations in human cancers. We hypothesized that FasL gene mutation might be involved in the development of non-Hodgkin lymphoma (NHL). In this study, we analyzed the entire coding region of the FasL gene for the detection of somatic mutations in a series of 111 NHLs and found that one tumor had a FasL gene mutation in the cytoplasmic domain. To evaluate the functional alterations of the mutant in apoptosis, we overexpressed the mutant in 293T cells, but couldn't find any significant loss of cell death compared to the wild-type FasL. Together, these data suggest that FasL is occasionally mutated in human NHL and that FasL mutations appear to play no role in the pathogenesis of the vast majority of NHLs.
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PMID:Mutational analysis of Fas ligand gene in human non-Hodgkin lymphoma. 1278 May 24

Resistance to Fas-mediated apoptosis (FMA) has been implicated in the pathogenesis of hematologic malignancies. Recently, a collaborative study showed that germline Fas mutations represent a genetic risk factor for the development of Hodgkin's and non-Hodgkin lymphoma. Here, we report that transformed B cell lines from familial lymphoma patients show a range of sensitivity to Fas-mediated apoptosis with lymphocytes from two patients with a marked resistance to Fas-, but not p53-mediated cell death. Fas resistance in these cells was associated with reduced recruitment of the initiator caspase 8 compared to cFlip, an inhibitor of apoptosis, to the death-inducing signaling complex (DISC). A decreased ratio of caspase 8 to cFlip in total cell extracts as well as in the DISC was associated with a profound disturbance of the Fas signaling cascade. We propose here that the relative reduction in caspase 8 to cFlip in the Fas DISC confers a survival advantage to lymphocytes and predisposes to the development of malignancy in some familial lymphoma patients.
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PMID:Differential recruitment of caspase 8 to cFlip confers sensitivity or resistance to Fas-mediated apoptosis in a subset of familial lymphoma patients. 1280 43

Resistance to death receptor-mediated apoptosis is supposed to be important for the deregulated growth of B cell lymphoma. Hodgkin/Reed-Sternberg (HRS) cells, the malignant cells of classical Hodgkin's lymphoma (cHL), resist CD95-induced apoptosis. Therefore, we analyzed death receptor signaling, in particular the CD95 pathway, in these cells. High level CD95 expression allowed a rapid formation of the death-inducing signaling complex (DISC) containing Fas-associated death domain-containing protein (FADD), caspase-8, caspase-10, and most importantly, cellular FADD-like interleukin 1beta-converting enzyme-inhibitory protein (c-FLIP). The immunohistochemical analysis of the DISC members revealed a strong expression of CD95 and c-FLIP overexpression in 55 out of 59 cases of cHL. FADD overexpression was detectable in several cases. Triggering of the CD95 pathway in HRS cells is indicated by the presence of CD95L in cells surrounding them as well as confocal microscopy showing c-FLIP predominantly localized at the cell membrane. Elevated c-FLIP expression in HRS cells depends on nuclear factor (NF)-kappaB. Despite expression of other NF-kappaB-dependent antiapoptotic proteins, the selective down-regulation of c-FLIP by small interfering RNA oligoribonucleotides was sufficient to sensitize HRS cells to CD95 and tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis. Therefore, c-FLIP is a key regulator of death receptor resistance in HRS cells.
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PMID:c-FLIP mediates resistance of Hodgkin/Reed-Sternberg cells to death receptor-induced apoptosis. 1507 99

Hodgkin's lymphoma (HL) is characterized by the presence of malignant so-called Hodgkin's/Reed-Sternberg (HRS) cells, which display resistance to certain apoptotic stimuli, including a lack of sensitivity to Fas-mediated cell death. However, the mechanisms responsible for their resistance to apoptosis inducers have not been elucidated. Here we confirm that both HL-derived cell lines and the HRS cells of primary HL tissues express Fas ligand (FasL) along with the inhibitory c-FLIP protein. Down-regulation of cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) through the use of specific small inhibitory RNAs (siRNAs) leads to reduced viability of the L428 and L591 HL-derived cell lines. To determine whether endogenous FasL was responsible for the reduction in cell viability observed after down-regulation of c-FLIP, L428 and L591 cells were treated with c-FLIP-specific siRNAs with and without siRNAs directed to FasL. Treatment of these cells with both c-FLIP- and FasL-specific siRNAs in combination restored cell viability to near control levels. Our results provide a mechanism whereby HRS cells are protected from autonomous FasL-mediated cell death while preserving their ability to evade immunosurveillance. Targeting c-FLIP could provide a novel approach to the treatment of HL.
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PMID:Expression of the cellular FLICE-inhibitory protein (c-FLIP) protects Hodgkin's lymphoma cells from autonomous Fas-mediated death. 1509 87

Autoimmune Lymphoproliferative Syndrome (ALPS) is generally the result of a mutation in genes associated with apoptosis, like Fas, Fas ligand, Casp 8 and Casp 10. As a result, the normal homeostasis of T- and B-lymphocytes is disturbed and a proliferation of polyclonal T lymphocytes occurs. This leads to hepatosplenomegaly and lymphadenopathy and in most patients also to autoimmune phenomena like anemia and thrombocytopenia. The proliferating T cells are TCRalphabeta and/or TCRgammadelta positive but lack both CD4 and CD8. Hence they are termed double negative (DN) T cells. In addition, there is an increase of CD5 positive B cells. Individuals with germline mutations in the Fas gene have a high risk to develop non Hodgkin lymphomas (x 14) as well as Hodgkin lymphomas (x 51), in particular NLP Hodgkin lymphoma. Somatic mutations of Fas are frequently acquired during the normal germinal center reaction. Non Hodgkin lymphomas carry somatic mutations of the Fas gene in 11% and of the Casp 10 gene in 14.5% of the patients. In Hodgkin lymphomas, Fas mutations can be demonstrated in Reed-Sternberg cells in 10-20% of the patients. These data implicate a role for Fas-mediated apoptosis in preventing lymphomas. Inherited defects in receptor-mediated lymphocyte apoptosis represent a risk factor for lymphomas and somatic mutations of these genes may also play a role in the development and/or progression of lymphomas.
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PMID:Development of lymphoma in Autoimmune Lymphoproliferative Syndrome (ALPS) and its relationship to Fas gene mutations. 1516 Sep 2

CD95 (Fas/APO-1)-mediated apoptosis plays an important role in immunological regulation and is related to the pathogenesis of autoimmune diseases. Immunoexpression of CD95 has been reported to frequently occur in low grade non-Hodgkin lymphomas, especially of post-germinal center histogenesis, among which those originating in mucosa-associated lymphoid tissue (MALT lymphomas). However, there is no report comparing in situ immunoexpression of this marker in lymphomas and the hyperplastic lymphoid reaction (chronic gastritis) related to Helicobacter pylori infection. The purpose of the present research was to compare the intensity of lymphoid CD95 immunoexpression in 15 cases of H. pylori-related chronic gastritis and 15 gastric MALT lymphomas. CD95 (anti-CD95) was detected by an immunoperoxidase technique in paraffin sections using the catalyzed amplification system. Graduation of reaction intensity (percentage of CD95-positive cells) was semiquantitative, from 1+ to 4+. Nine cases of chronic gastritis were 4+, five 2+ and one 1+. Three lymphomas were 4+, three 3+, four 2+, four 1+, and one was negative. Although 14 of 15 lymphomas were positive for CD95, the intensity of the reaction was significantly weaker compared to that obtained with gastric tissue for patients with gastritis (P = 0.03). The difference in CD95 immunoexpression does not seem to be useful as an isolated criterion in the differential diagnosis between chronic gastritis and MALT lymphomas since there was overlapping of immunostaining patterns. However, it suggests the possibility of a pathogenetic role of this apoptosis-regulating protein in MALT lymphomas.
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PMID:Immunoexpression of CD95 in chronic gastritis and gastric mucosa-associated lymphomas. 1533 6

Different molecular pathways are believed to be involved in the pathogenesis of classic Hodgkin lymphoma as opposed to non-Hodgkin lymphoma. Antiapoptotic mechanisms have been proposed for classic Hodgkin lymphoma, including expression of the cellular Fas-associated death domain-like interleukin-1beta-converting enzyme inhibitory protein (c-FLIP), which plays a critical role in resistance to CD95/Fas-mediated apoptosis. In this study, we compare the expression of c-FLIP in the neoplastic cells of classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma cases. Sixteen cases of classic Hodgkin lymphoma and 19 cases of nodular lymphocyte-predominant Hodgkin lymphoma were reviewed. Of 16 classic Hodgkin lymphoma cases, 13 cases (81%) were c-FLIP-positive, compared with 6 of 19 (32%) nodular lymphocyte-predominant Hodgkin lymphoma cases. Strong cytoplasmic staining was seen in 7 of 13 c-FLIP-positive classic Hodgkin lymphoma cases, in contrast with only 2 of 6 c-FLIP-positive nodular lymphocyte-predominant Hodgkin lymphoma cases. The 2 cases of nodular lymphocyte-predominant Hodgkin lymphoma with strong c-FLIP expression were associated with transformation to large B-cell lymphoma. An additional 15 cases of diffuse large B-cell lymphoma were studied for c-FLIP expression. All but 1 were c-FLIP-positive. In conclusion, we detected c-FLIP in a significantly lower proportion of nodular lymphocyte-predominant Hodgkin lymphoma cases compared with classic Hodgkin lymphoma cases. Therefore, c-FLIP expression may not be the major mechanism of pathogenesis in nodular lymphocyte-predominant Hodgkin lymphoma. However, strong c-FLIP expression in nodular lymphocyte-predominant Hodgkin lymphoma was associated with transformation to large B-cell lymphoma in 2 cases. c-FLIP expression is not limited to Hodgkin lymphoma, because the majority of diffuse large B-cell lymphoma cases tested were strongly c-FLIP-positive.
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PMID:Expression of c-FLIP in classic and nodular lymphocyte-predominant Hodgkin lymphoma. 1535 34

Effector-memory T cells expressing Fas (Apo-1/CD95) are switched to an apoptotic program by cross-linking with Fas-ligand (FasL). Consequently, tumors that express FasL can induce apoptosis of infiltrating Fas-positive T lymphocytes and subdue any antitumor host immune response. Since Epstein-Barr virus (EBV)-associated tumors such as Hodgkin lymphoma (HL) and nasopharyngeal carcinoma (NPC) express FasL, we determined whether EBV-specific cytotoxic T lymphocytes (EBV-CTLs) could be modified to resist this evasion strategy. We show that long-term down-modulation of Fas can be achieved in EBV-CTLs by transduction with small interfering RNA (siRNA) encoded in a retrovirus. Modified T cells resisted Fas/FasL-mediated apoptosis compared with control cells and showed minimal cleavage of the caspase3 substrate poly(ADP-ribose) polymerase (PARP) protein after Fas engagement. Prolonged Fas stimulation selected a uniformly Fas(low) and FasL resistant population. Removal of responsiveness to this single death signal had no other discernible effects on EBV-CTLs. In particular, it did not lead to their autonomous growth since the modified EBV-CTLs remained polyclonal, and their survival and proliferation retained dependence on antigen-specific stimulation and on the presence of other physiologic growth signals. EBV-CTLs with knocked down Fas should have a selective functional and survival advantage over unmodified EBV-CTLs in the presence of tumors expressing FasL and may be of value for adoptive cellular therapy.
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PMID:Human cytotoxic T lymphocytes with reduced sensitivity to Fas-induced apoptosis. 1571 95

Perforin mutations have been demonstrated in a proportion of patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH). In the present study, we evaluated whether some patients with lymphoma sharing clinical characteristics with HLH might harbor mutations of the perforin gene. We analyzed 29 patients and found that 4 patients, who developed either Hodgkin or non-Hodgkin lymphoma, had biallelic mutations of the perforin gene. One of these 4 patients, a 19-year-old female with T-cell lymphoma, had a brother carrying the same mutations who developed HLH. In 2 of the 4 patients with biallelic mutations of the perforin gene, we evaluated perforin expression by flow cytometry and natural killer (NK) activity and both were found to be absent. Moreover, we documented the presence of monoallelic mutations of the perforin gene in 4 more patients. One of these 4 latter patients also carried a mutation of the Fas gene. These data indicate that perforin deficiency, either alone or in combination with other mutations of genes involved in lymphocyte survival or functional activity, may be present in patients with lymphoma. These findings suggest that perforin also plays a key role in the mechanisms of immune surveillance that prevent tumor growth and/or development.
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PMID:A proportion of patients with lymphoma may harbor mutations of the perforin gene. 1572 24

Classical Hodgkin lymphoma (cHL) is a distinct malignancy of the immune system. Despite the progress made in the understanding of the biology of cHL, the transforming events remain to be elucidated. Recently, we demonstrated that the Janus kinase inhibitor AG490 blocked cellular proliferation and STAT3 phosphorylation in cHL. To explore the potential of constitutively activated STAT3 as a drug target and its role in cHL pathogenesis, different cHL cell lines were analyzed. Treatment of cHL cells by the protein tyrosine kinase inhibitor AG17 was associated with inhibition of cellular proliferation and cell cycle arrest. AG17 treatment was accompanied by decreased levels of STAT3 phosphorylation, whereas NF-kappaB and p38/SAPK2 signaling were not inhibited. Incubation with AG17 or AG490 sensitized cHL cells to CD95/Fas/Apo-1 or staurosporine-mediated apoptosis. Coincubation of tyrphostins with staurosporine was accompanied by rapid complete inhibition of STAT3 phosphorylation. RNA interference directed against STAT3 in L428 and L1236 cHL cells demonstrated that STAT3 is essential for cell proliferation of these cHL cells. In conclusion, these findings support the concept that STAT3 signaling is important in the pathogenesis of cHL and tyrphostins are agents for developing new therapeutic strategies.
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PMID:STAT3 is essential for Hodgkin lymphoma cell proliferation and is a target of tyrphostin AG17 which confers sensitization for apoptosis. 1591 44


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