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

Among patients with congenital and acquired immunodeficiencies, non-Hodgkin's lymphoma (NHLs ) are the most common tumors of the immune system. In the setting of human immunodeficiency virus (HIV) infection, as many as 10% to 20% of people ultimately developed NHLs. These tumors are clinically aggressive, frequently involve extranodal sites, and often exhibit unique features that distinguish them from NHL arising in individuals with other forms of immunosuppression. Important in the development of HIV-associated NHL are cytokines and other factors that induce B-cell proliferation and increase the likelihood of mutations of c-myc, bcl-6, and other tumor-suppressor genes with carcinogenic potential. Specific forms of HIV-associated NHL are linked to expression of Epstein-Barr virus (EBV)-latent proteins; the newly described DNA virus, Karposi's sarcoma-associated herpesvirus/human herpesvirus-8 (KSHV/HHV-8); and perhaps HIV. Elucidation of the factors that contribute to the high incidence of NHL among patients infected with HIV provides insights into important elements of lymphomagenesis.
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PMID:Epidemiology and pathogenesis of AIDS-related lymphomas. 968 78

Hepatitis virus, especially hepatitis C virus(HCV), is suggested to be associated with lymphomagenesis. A high prevalence(33%) of HCV among non-Hodgkin's lymphoma(NHL) patients has been reported mainly in Italy, but the prevalence is low in other countries. HCV-related NHL is varied histopathologically, including diffuse large B cell lymphoma, immunocytoma or follicular lymphoma(REAL). The HCV genotypes involved are 1b, 2a or 2c(Simmonds). Although HCV RNA + strand has been detected in lymphoma tissue in various studies, there are not many studies in which HCV RNA-strand has been detected. Recent studies have shown that BCL-2 plays an important role in lymphoproliferation by suppressing apoptosis, that HCV core protein regulates c-myc transcription and that BCL-2 and c-myc work together in lymphomagenesis. It seems difficult to provide reasonable explanations regarding these puzzling epidemiological findings and lymphomagenesis.
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PMID:[Hepatitis virus and malignant lymphoma]. 1074 Nov 25

Treatment of patients with non-Hodgkin's lymphoma (NHL) is frequently hampered by development of chemoresistance. Rituximab is a chimeric mouse antihuman CD20 antibody that offers an alternative; however, its mechanism of action is not clearly understood. Treatment of lymphoma cell lines with Rituximab sensitizes the cells to the cytotoxic and apoptotic effects of therapeutic drugs, e.g., cisplatin, fludarabine, vinblastine, and Adriamycin. This study investigated the mechanism(s) involved in the reversal of drug resistance by Rituximab therapy. NHL cells synthesize and secrete antiapoptotic cytokines implicated in drug resistance, including interleukin (IL)-6, IL-10, and tumor necrosis factor alpha. We hypothesized, therefore, that sensitization by Rituximab may be due in part to modification of cytokine production. In this study, examination of cytokine secretion by NHL 2F7 tumor cells revealed down-regulation of IL-10 by Rituximab treatment. Moreover, cytotoxicity assays using exogenous IL-10 and IL-10-neutralizing antibodies demonstrated that IL-10 serves as an antiapoptotic/protective factor in these tumor cells against cytotoxic drugs. Furthermore, expression in 2F7 cells of the protective factor, Bcl-2, was shown to be dependent on IL-10 levels and down-regulated by Rituximab. Other gene products such as Bax, Bcl-x, Bad, p53, c-myc, and latent membrane protein-1 (LMP) were not affected by Rituximab treatment. Drug sensitization, as well as down-regulation of both IL-10 and Bcl-2, was corroborated in experiments using the NHL cell line 10C9. The Ramos and Daudi NHL cell lines were not sensitizable, nor did their Bcl-2 or IL-10 levels change. These studies demonstrate that one mechanism by which Rituximab sensitizes NHL to chemotherapeutic drugs is mediated through down-regulation of antiapoptotic IL-10 autocrine/paracrine loops and Bcl-2. The clinical relevance of these findings is discussed.
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PMID:Inhibition of interleukin 10 by rituximab results in down-regulation of bcl-2 and sensitization of B-cell non-Hodgkin's lymphoma to apoptosis. 1129 68

Primary mediastinal B-cell lymphoma (PMBL) is a distinct clinical entity among non-Hodgkin's lymphoma. The malignancy has received little attention from a standpoint of basic research due in part to its rarity. However, based on recent studies consistent trends are beginning to emerge regarding the molecular and chromosomal alterations commonly observed in this disease. By both CGH and AP-PCR, genetic gains involving chromosomes 2, 5, 7, 9p, 12, and Xq are among the most frequently observed events. From a molecular standpoint, alterations in the c-myc, p16(INK4) and p53 genes have been observed in up to 30% of cases. This information along with the well-established histological, immunological, and clinical features should convince the few remaining disbelievers that PMBL is a distinct pathological entity among non-Hodgkin's lymphomas.
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PMID:Genetic alterations in primary mediastinal B-cell lymphoma: an update. 1134 56

To compare immunophenotypic and molecular features between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) with c-myc rearrangements (c-mycR DLBCL), we analyzed 18 cases of B-cell non-Hodgkin's lymphoma with c-mycR that were confirmed by chromosomal and/or Southern blotting analyses. The cases were histologically classified into 10 BLs and five DLBCLs. The remaining three cases could not be classified because of suboptimal quality of the surgical materials. BLs were from five adults and five children, whereas all DLBCLs were from adults. BLs were positive for CD20 (10/10 cases examined), CD10 (9/10), Bcl-2 (1/9), and Bcl-6 (10/10), whereas they were negative for CD3 (0/10) and EBV (0/8), by Epstein-Barr virus (EBV) EBER-1 RNA in situ hybridization. c-MycR DLBCLs were positive for CD20 (5/5), CD10 (2/5), Bcl-2 (3/4), and Bcl-6 (4/4), whereas none of them were positive for CD3 and EBV. A mean of MIB-1 index (MIB-1+ cells/neoplastic cells, %) of BLs (98.1%) was higher than that of c-mycR DLBCLs (66.3%; P <.0001). Somatic mutation of immunoglobulin heavy-chain gene variable region (VH gene) in BLs (four cases) ranged from 0.7 to 4.9% with an average value of 2.3%, whereas those in DLBCLs (three cases) from 8.2 to 32.0% with an average value of 17.0%. It is, therefore, concluded that a growth fraction of nearly 100%, as well as a monotonous proliferation of medium-sized cells and c-myc(R), should be of value in the diagnosis of BL, which is probably different from c-myc(R) DLBCL. In addition, CD10+, Bcl-2-, and low frequency of mutation of the VH gene could be helpful for the histologic distinction of BL from (c-mycR) DLBCL.
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PMID:The distinction between Burkitt lymphoma and diffuse large B-Cell lymphoma with c-myc rearrangement. 1211 16

Philadelphia chromosome-positive (Ph+) acute leukaemia usually shows lymphoblastic morphology and a B-precursor phenotype. The bone marrow aspirate of a 9-year-old boy showed a L3 blast cell morphology in 90% of cells; immunophenotyping revealed a mature B-blast population. The translocation t(9;22) (q34;q11) was seen in 45 out of 50 metaphases, and expression of the corresponding bcr1/abl fusion transcripts, but no IgH/myc co-localization or splitting of c-myc, was demonstrated. Chemotherapy according to the Berlin-Frankfurt-Munster non-Hodgkin's lymphoma (NHL-BFM 95) protocol with maintenance according to the BFM acute lymphoblastic leukaemia (ALL-BFM 90) protocol resulted in continuing complete remission of 54 months. The occurrence of Ph+ Burkitt's leukaemia might reflect multiple-step cancer development.
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PMID:Philadelphia chromosome-positive mature B-cell (Burkitt cell) leukaemia. 1213 45

Burkitt's lymphoma and small noncleaved Burkitt's-like lymphoma are rare and are highly aggressive forms of non-Hodgkin's lymphoma that are characterized by dysregulation of the c-myc oncogene. Patients with human immunodeficiency virus (HIV) also appear to be at risk for developing Burkitt's lymphomas. Treatment options for Burkitt's lymphoma involve complex chemotherapy regimens that contain as many as 10 cytotoxic agents. Approximately 50%-80% of adult patients with Burkitt's lymphoma or small, noncleaved lymphoma can be cured with these intensive chemotherapy regimens, and in pediatric populations, the cure rate is even higher. However, a number of factors often compromise the outcome of patients with Burkitt's lymphoma. For instance, the high proliferation rate of Burkitt's lymphoma enhances the risk for tumor lysis syndrome, which results from metabolic imbalances, such as hyperuricemia, that occur as large numbers of malignant cells are lysed during cytotoxic chemotherapy. Standard treatment for tumor lysis syndrome includes adjustments in the chemotherapy regimen, vigorous hydration, administration of a uric acid synthesis inhibitor like allopurinol, and alkalinization. The administration of recombinant urate oxidase (rasburicase) also has been shown to provide effective prophylaxis against hyperuricemia in pediatric and adult patients with hematologic malignancies. The lifetime risk of developing central nervous system disease is 20%-30% for Burkitt's lymphoma. Consequently all chemotherapy regimens with activity in Burkitt's lymphoma utilize some form of central nervous system prophylaxis, such as systemic or intrathecal methotrexate or cytarabine. In the past, patients with HIV who developed Burkitt's lymphoma often received inadequate chemotherapy doses because of their immunosuppression. With the discovery of highly active antiretroviral therapy, the ability to treat and control Burkitt's lymphoma in patients with HIV has improved.
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PMID:Challenges in the management of Burkitt's lymphoma. 1252 85

Burkitt's lymphoma (BL) and its variants, including Burkitt-like lymphoma (BLL), can be difficult to distinguish morphologically and immunophenotypically from diffuse large B-cell lymphoma (DLBCL). Because the treatment of BL differs markedly from that of other types of non-Hodgkin's lymphoma (NHL), exact pathological diagnosis is crucial. We report 2 cases of patients with BL initially diagnosed as DLBCL. Due to clinical features typical of BL, long distance polymerase chain reaction (PCR) for detecting the t(8;14) translocation involving the c-myc proto-oncogene was performed on ascites lymphoma cells. Re-evaluation by a reference hematopathologist, together with long distance PCR in both patients revealing the t(8;14) translocation, resulted in diagnosis modification to BL and BLL. Consequently, the patients were treated with intense high-dose chemotherapy regimens including central nervous system (CNS) prophylaxis, and complete remission was initially achieved in both patients. Both BL and BLL should be considered in the differential diagnosis of DLBCL if abdominal spread with ascites and metabolic disorders are present. Long distance PCR analysis of ascites lymphoma cells for the detection of the BL-typical c-myc rearrangement offers a convenient and rapid possibility of diagnosis verification in atypical or borderline cases of BL.
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PMID:Long distance polymerase chain reaction of ascites lymphoma cells aids diagnosis establishment of abdominal Burkitt's lymphoma and Burkitt-like lymphoma. 1562 85

Primary effusion lymphoma (PEL) is a rare subtype of non-Hodgkin's lymphoma, which is associated with infection by Kaposi's sarcoma herpesvirus (KSHV)/human herpesvirus-8. The c-Myc transcription factor plays an important role in cellular proliferation, differentiation and apoptosis. Lymphomas frequently have deregulated c-Myc expression owing to chromosomal translocations, amplifications or abnormal stabilization. However, no structural abnormalities were found in the c-myc oncogene in PEL. Given that c-Myc is often involved in lymphomagenesis, we hypothesized that it is deregulated in PEL. We report that PEL cells have abnormally stable c-Myc protein. The turnover of c-Myc protein is stringently regulated by post-transcriptional modifications, including phosphorylation of c-Myc threonine 58 (T58) by glycogen synthase kinase-3beta (GSK-3beta). Our data show that the impaired c-Myc degradation in PEL cells is associated with a significant underphosphorylation of c-Myc T58. The KSHV latency-associated nuclear antigen (LANA) is responsible for this deregulation. Overexpression of LANA in human embryonic kidney 293 or peripheral blood B cells leads to post-transcriptional deregulation of c-Myc protein. Conversely, when LANA is eliminated from PEL cells using RNA interference, GSK-3beta-mediated c-Myc T58 phosphorylation is restored. The presence of c-Myc and LANA in GSK-3beta-containing complexes in PEL cells further confirms the significance of these interactions in naturally KSHV-infected cells.
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PMID:Deregulation of c-Myc in primary effusion lymphoma by Kaposi's sarcoma herpesvirus latency-associated nuclear antigen. 1731 Sep 99

Plasmablastic lymphoma (PBL) is a rare acquired immunodeficiency syndrome-associated non-Hodgkin's lymphoma (AIDS-NHL), with predilection for the mucosa of oral cavity. It usually has a plasmablastic morphology, expressing plasma cell-associated antigens with weak or absent expression of B-cell-associated markers. To further define the immunophenotypic and molecular genetics of these tumors, we investigated two cases of plasmablastic lymphomas of the head and neck for c-myc gene rearrangement and immunoglobulin heavy chain (IgV(H)) hypermutation status. For the first time we report a case of AIDS-related PBL that, by fluorescence in situ hybridization (FISH), shows a c-myc gene rearrangement. Although current literature suggests that most cases of c-myc gene rearranged AIDS-NHL are Burkitt's lymphoma, our case has an immunophenotype characteristic for PBL. In this case, IgV(H) hypermutation analysis showed a somatic hypermutation, indicative of germinal center transit. The concurrent B-cell immunophenotype of BCL-6(-)/CD138(+)/MUM-1(+) also suggests a post-germinal center B-cell origin of this lymphoma. The immunophenotype of our second case (BCL-6(-)/CD138(+)/MUM-1(+)) also suggests a post-germinal center B-cell origin. However, IgV(H) hypermutation analysis was not possible in this case.
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PMID:Plasmablastic lymphoma of head and neck: report of two new cases and correlation with c-myc and IgVH gene mutation status. 2061 67


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