Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:A9QXG9 (bcl-2)
7,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the work it has been decided to evaluate the occurrence of locus bcl-1 rearrangement in type B chronic lymphatic leukemia and that of gene bcl-2 in non-Hodgkin's lymphoma with diffuse morphology, as well as in reactive lymph nodes. The study material comprised DNA isolated from fragments of lymph nodes sent for routine diagnostic examinations at the Institute of Pathology--Pomeranian Medical Academy. Southern's method was used to examine DNA having been cut with restrictive enzymes, estimating the distribution of gene bcl-2 and locus bcl-1. Resorting to Polymerase Chain Reaction (PCR) translocation t (14;18) was assessed by means of short nucleotides hybridizing with 14 and 18 chromosome sequences restricting this translocation. The amplification product was subsequently studied by Southern's method with probe bcl-2. In 1 out of 18 examined cases of type B chronic lymphocyte leukemia it was disclosed that locus bcl-1 had been rearranged. In 45 cases of non-Hodgkin's lymphoma with diffuse morphology the gen bcl-2 was found to display germline arrangement. Germline position of gen bcl-2 was also revealed in 60 cases of reactive lymph nodes.
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PMID:[Molecular-genetic evaluation of translocation of bcl-2 gene and locus bcl-1 in selected lymphoproliferative changes]. 129 Mar 53

Polymerase chain reaction (PCR) of bcl-2 provides an extremely sensitive method to detect minimal disease in approximately 50% of patients with non-Hodgkin's lymphomas (NHL). In an attempt to determine the clinical usefulness of this technique, we examined the bone marrow (BM) of 152 patients with advanced-stage NHL at the time of evaluation and after induction or salvage chemotherapy before autologous BM transplantation. The BM proved to be an accessible and reproducible tissue source to determine PCR positivity because all of the 102 patients examined had the same PCR-amplifiable breakpoint in their BM and lymph node. At the time of evaluation, PCR analysis in advanced-stage NHL patients added little additional information to morphologic analysis because each technique identified BM infiltration in approximately 70% of patients. PCR was significantly more useful in determining BM infiltration after induction or salvage therapy. At that time, approximately 50% of patients had morphologically normal BM, whereas PCR analysis remained positive in 100% of those with an amplifiable breakpoint. These observations were confirmed in a clinical trial attempting to induce remission in previously untreated low-grade advanced-stage NHL patients. In this series, PCR was positive in all patients after treatment although the BM was histologically uninvolved in 50% of cases, showing that conventional therapy did not eradicate bcl-2-positive cells.
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PMID:All advanced stage non-Hodgkin's lymphomas with a polymerase chain reaction amplifiable breakpoint of bcl-2 have residual cells containing the bcl-2 rearrangement at evaluation and after treatment. 174 87

As part of an effort to develop a better understanding of the relationship between nodal monocytoid B-cell lymphomas (MBCLs) and follicular lymphomas (FLs) when they coexist (MBCL + FL) and to assess the validity of the morphological criteria for the latter diagnosis, we evaluated follicular colonization, bcl-2 reactivity, light chain restriction, and the presence of t(14;18) in 14 benign lymph node specimens containing benign monoclonal B cells (MBCs), in eight nodal specimens of pure MBCL, and in 17 nodal specimens of MBCL coexisting with FL (MBCL + FL). Follicular colonization by malignant MBCs was observed in six specimens of pure MBCL and in 13 specimens of MBCL + FL. Benign MBCs did not express bcl-2 by immunohistological methods in 11 of 12 benign specimens. In contrast, weak reactivity for bcl-2 was detected in malignant MBCs in four of five specimens of pure MBCL and in the MBCL component in 13 of 15 specimens from the MBCL + FL group. In the FL component of 13 specimens, the bcl-2 was strongly positive. Identical light chain restriction was detected by immunohistological methods in both the FL component and the MBCL component in 15 specimens of MBCL + FL. Polymerase chain reaction analysis did not detect the t(14;18) translocation in any of 10 benign specimens or any of six evaluable pure MBCL specimens. In contrast, the translocation was detected in whole sections from eight of 12 specimens of MBCL + FL. Thus, on the one hand, the high incidences of follicular colonization and the coexistence of MBCL and FL as well as the identical light chain restriction in MBCL and FL components of MBCL + FL cases suggest that possibly these are related closely when they coexist. On the other hand, the bcl-2 and t(14;18) data cannot be used as evidence in support of a close relationship.
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PMID:Nodal benign and malignant monocytoid B cells with and without follicular lymphomas: a comparative study of follicular colonization, light chain restriction, bcl-2, and t(14;18) in 39 cases. 777 92

There are conflicting data regarding the detection of t(14;18) in reactive lymphoid hyperplasia (RLH) by the polymerase chain reaction (PCR). Although most studies have not detected t(14;18), several groups have definitively shown that a very low number of cells with this translocation (one in 10(5) to 10(6)) are present in a significant proportion of follicular hyperplasias. Review of the methods from these series reveals that modifications of the PCR assay (ie, enhanced sensitivity steps such as seminesting, lengthy autoradiographic exposure times, multiple aliquot reactions of single samples, and/or high concentrations of template DNA) are probably necessary to detect t(14;18) in RLH. We evaluated a diverse set of 111 RLH (85 lymph nodes, 22 tonsils, and four other sites) from patients of different age groups (age range, 9 months to 80 years) to determine if a standard PCR assay would amplify t(14;18). Of these, 61 (55%) specimens had a prominent follicular hyperplastic component. Fifty-seven follicular lymphomas served as a control group. Polymerase chain reaction was performed as a single-run, two-primer-based assay for major breakpoint region bcl-2 translocations (5' major breakpoint region primer and 3' immunoglobulin heavy-chain gene-joining region consensus primer). Two different types of thermocyclers were employed. A metal block thermocycler was used with 35 cycles of amplification on 500 ng to 1 micrograms of genomic DNA, and a separate air thermocycler was used with 45 cycles of amplification on 50 ng of genomic DNA. Product detection was carried out through ethidium bromide staining and UV gel illumination, along with a digoxigenin-alkaline phosphatase-based, internal major breakpoint region oligonucleotide probe system. We found no amplified t(14;18) products in any RLH. In contrast, 36 (63%) of 57 follicular lymphomas showed t(14;18) (published range for detection of major breakpoint region translocations by PCR, 31% to 74%). Moreover, the assay's sensitivity, estimated through dilution studies, was to one in 10(4) to 10(5) cells. Although theoretically possible, our data suggest that there is practically no risk of amplifying a t(14;18) from RLH when utilizing a standard PCR assay.
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PMID:Standard polymerase chain reaction analysis does not detect t(14;18) in reactive lymphoid hyperplasia. 806 Feb 26

We herein provide evidence for the existence of a distinct morphologic form of small lymphocytic lymphoma (SLL) that we term follicular small lymphocytic lymphoma (FSLL). Nine specimens of FSLL from eight patients were studied. The lymphomas in this study showed a true follicular pattern that was independent of tissue planes; the cytologic composition was identical to that seen in SLL. All six of the specimens (from five patients) for which paraffin tissue was available marked as B cell phenotype and were positive for bcl-2 protein. Polymerase chain reaction studies performed on deparaffinized tissue sections showed bcl-2 major breakpoint region rearrangements in four of five cases for which study tissue was available. Clinical information was available for all eight patients. All patients presented with lymph node disease, and three patients also had extranodal involvement at the time of presentation. Three of the patients had a relapse of disease after 33-95 months, and two of these patients died soon after relapse. Another two of the eight patients never responded to chemotherapy and died of their disease after 2 and 8 months, respectively. Two patients died of causes unrelated to their lymphoma and unrelated to any lymphoma therapy. Only one patient remains disease-free, after 65 months; this patient had a relapse at 44 months. The finding of bcl-2 rearrangements suggests that the pathogenesis of FSLL is more closely related to follicular small cleaved cell lymphoma than to classic SLL.
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PMID:Follicular small lymphocytic lymphoma. 809

Follicular lymphomas comprise almost two thirds of the US adult non-Hodgkin's lymphomas (NHL) and are the most common malignancy of B-lineage lymphocytes. Polymerase chain reaction (PCR) protocols have been developed to detect the t(14;18) translocation, which juxtaposes the bcl-2 proto-oncogene to the Ig heavy-chain (IgH) gene in 85% of follicular lymphomas and monoclonal rearrangements of the IgH gene in B-cell NHL that lack bcl-2 rearrangements. We used PCR to amplify bcl-2 and IgH rearrangements in DNA from patients with lymphoproliferative disorders and analyzed the products in parallel by gel electrophoresis and flow cytometry, which detected PCR products incorporating fluoresceinated oligonucleotide primers by sequence-specific capture to oligonucleotide-coated magnetic beads. Overall, flow cytometry was superior to electrophoresis of ethidium-bromide-stained agarose gels for detection of products of nested PCR to detect intergenic rearrangements involving bcl-2 and single primer-pair amplification of clonal rearrangement of IgH. Flow cytometric analysis detected bcl-2 translocations in 12 of 13 CD10+ B-cell lymphomas and clonal IgH rearrangements in 14 of 17 monoclonal B-cell populations. In contrast, analysis by gel electrophoresis detected bcl-2 translocations in only 10 of 13 CD10+ and clonal IgH gene rearrangements in only 9 of 17 monoclonal B-cell populations. Flow cytometric analysis was more sensitive than gel electrophoresis and could detect a 16-fold greater dilution of a bcl-2-amplified product than gel electrophoresis. Similarly, flow cytometry could detect an amplification product when template DNA was diluted 10,000-fold, whereas gel electrophoresis only detected amplification products when template was subjected to dilution between 100- and 1,000-fold. This shows the utility of flow cytometry for the analysis of DNA amplification products incorporating fluorochrome-labeled primers as a rapid, objective alternative to conventional strategies. Because current-generation clinical laboratories emphasize automation, flow cytometric analysis of PCR-amplified products shows increased analytic sensitivity and offers a vehicle for automation of DNA amplification tests.
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PMID:Cytometric detection of DNA amplified with fluorescent primers: applications to analysis of clonal bcl-2 and IgH gene rearrangements in malignant lymphomas. 811 Oct 48

Paired samples of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) and the subsequent diffuse large cell lymphoma (DLL) of six cases of Richter's syndrome were investigated to establish the clonal relationship between the CLL/SLL and the DLL components and to define the oncogene and/or tumor-suppressor gene alterations involved in the morphologic transformation of CLL/SLL. Southern blot hybridization analysis showed identical clonal immunoglobulin (Ig) gene-rearrangement patterns in the CLL/SLL and DLL components in four cases and different Ig gene-rearrangement patterns in two cases. Polymerase chain reaction (PCR) amplification, cloning, and DNA sequencing of complementary determinant region 3 (CDR3) of the Ig-heavy chain gene of one of the two cases in which the Ig gene-rearrangement patterns were different showed nonidentical sequences in the CLL/SLL and DLL components. In the other case, monomorphic Epstein-Barr virus (EBV) genome integration was detected in the DLL but not in the CLL, suggesting that the CLL and DLL components in this case of Richter's syndrome also represent unrelated clones. Single-strand conformation polymorphism (SSCP) analysis and sequencing of exons 5 through 9 of the p53 tumor-suppressor gene showed a mutation in codon 176 of the DLL but not in the CLL/SLL component in one case where the CLL/SLL and DLL represented different clones. The p53 mutation probably played a role in the development of the lymphoma rather than morphologic transformation of the CLL/SLL in this case. SSCP analysis and sequencing also showed identical mutations in codon 282 in both the CLL/SLL and DLL components in a case where the CLL and DLL represented identical clones. Thus, this p53 gene mutation was present both before and after morphologic transformation, and therefore, probably did not play a primary role in this process. Southern blot hybridization analysis failed to show evidence of bcl-1, bcl-2, c-myc proto-oncogene or retinoblastoma (Rb) tumor-suppressor gene rearrangements in these six cases of Richter's syndrome. In conclusion, the original CLL/SLL and the subsequent DLL in Richter's syndrome may or may not be derived from identical clones, and the well-known proto-oncogenes and tumor-suppressor genes do not appear to play an obvious and consistent role in the morphologic transformation of CLL/SLL to DLL.
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PMID:Molecular genetic demonstration of the diverse evolution of Richter's syndrome (chronic lymphocytic leukemia and subsequent large cell lymphoma). 811 38

Splenic marginal zone cell lymphoma (SMZCL) is a recently described clinicopathologic entity, that is reported to overlap with splenic B-cell lymphoma with villous lymphocytes. The authors describe the clinicopathologic, immunophenotypic, and molecular findings in five cases of SMZCL. There were two males and three females, with a mean age of 68.4 years, who presented with peripheral blood cytopenias and splenomegaly. One patient had an absolute lymphocytosis with many villous lymphocytes. With clinical follow-up of 9 to 37 months, two patients are alive and three patients died of unrelated causes. Splenectomy was done in each patient and the spleens were large, 970-2,400 g. Histologically, the SMZCLs preferentially replaced the marginal and mantle zones with partial or complete replacement of germinal centers in the white pump. The neoplastic cells were predominantly small to medium in size with oval or slightly irregular nuclei and relatively abundant pale or eosinophilic cytoplasm. Immunophenotypic studies demonstrated that the neoplastic cells expressed monotypic immunoglobulin, IgD in four tumors, pan-B-cell antigens, and bcl-2. The tumor cells were negative for the CD2, CD3, CD5, CD10, CD11c, CD25, CD35, CD38, CD45RO, and CD68 antigens, and tartrate-resistant acid phosphatase. Southern blot hybridization revealed immunoglobulin gene rearrangements in all tumors. The major breakpoint region of the bcl-2 gene and the T-cell receptor beta chain gene were in the germline configuration. Polymerase chain reaction studies did not identify the t(14;18) or t(11;14). All cases were negative for p53 protein and single-stranded conformational polymorphism analysis for p53 gene mutations was negative. Our results support the concept that SMZCL is a clinically indolent, low grade B-cell lymphoma that probably arises from splenic marginal zone lymphocytes.
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PMID:Splenic marginal zone cell lymphoma. An immunophenotypic and molecular study of five cases. 860 7

The bcl-2 protein, which protects cells from apoptosis, is normally expressed in a number of adult tissues. Dysregulated bcl-2 expression, secondary to (14;18) chromosomal translocation, seems to promote the development of follicular lymphomas, and recent findings of bcl-2 protein in several solid tumors suggest that it might contribute to the genesis of many other neoplasms. bcl-2 is also highly expressed in normal proliferative endometrium and markedly down-regulated in secretory endometrium, which suggests that its expression is estrogen regulated. Because the development of most endometrial carcinomas is associated with hyperestrogenic states, we began the investigation of the role of bcl-2 in endometrial carcinogenesis by immunohistochemically quantifying its expression in proliferative, hyperplastic, atypically hyperplastic, and carcinomatous endometrium. The results of this study show that bcl-2 is relatively highly expressed in proliferative (n = 11) and hyperplastic (n = 18) endometrium, with respective mean staining scores of 3.59 and 3.47 (scale, 0-4), but is significantly (P < 0.001) down-regulated in atypical hyperplasia (n = 11; score, 0.82), and adenocarcinoma (n = 34; score, 0.86). bcl-2 expression did not correlate with stage, grade, estrogen-receptor, or progesterone-receptor expression. Polymerase chain reaction analyses of DNA isolated from several endometrial carcinomas were negative for (14;18) translocation involving the bcl-2 gene. Thus, bcl-2 apparently plays no role in the progression of atypical hyperplasia to carcinoma or in the development of high-grade or advanced-stage endometrial carcinoma. These results, however, do not rule out the involvement of bcl-2 in very early, preatypical hyperplasia phases of endometrial carcinogenesis. Finally, the marked difference in bcl-2 expression in hyperplastic and atypically hyperplastic glands might prove to be diagnostically useful in the often difficult distinction of these entities.
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PMID:bcl-2 is down-regulated in atypical endometrial hyperplasia and adenocarcinoma. 872 85

Polymerase chain reaction (PCR) and immunohistochemical staining methods were used to detect the bcl-2/IgH fusion gene [t(14:18)] and the overexpression of bcl-2 protein in 28 cases of follicular lymphomas and 18 cases of reactive follicular hyperplasia. The results showed that the bcl-2/IgH fusion gene was present in 57% of follicular lymphomas and that this translocation was also present in 33% of the reactive follicular hyperplasia cases. The over expression of bcl-2 protein was found in 78% of follicular lymphomas, but none in follicular hyperplasia, therefore bcl-2 protein staining may be a useful immunohistochemical method to differentiate follicular lymphoma and follicular hyperplasia.
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PMID:[t(14:18) chromosomal translocation and over expression of bcl-2 protein in follicular type non-Hodgkin's lymphoma]. 873 86


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