Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mantle-cell lymphoma (MCL) is a lymphoproliferative disorder derived from a subset of naive pregerminal center cells characterized by a nodular or diffuse proliferation of atypical lymphoid cells with a monoclonal B-cell phenotype and coexpression of CD5. Two cytologic variants have been identified, typical and blastic. Typical cases show a proliferation of small to intermediately sized lymphoid cells with irregular nuclei and scarce cytoplasm. Blastic variants include a spectrum of intermediate to large cells with round or irregular nuclei and finely dispersed chromatin. These cases have a higher proliferative activity and a more aggressive clinical evolution. MCL is genetically characterized by 11q13 translocations and bcl-1 rearrangement. This alteration leads to a constant overexpression of cyclin D1, which plays an important pathogenetic role, probably deregulating cell-cycle control by overcoming the suppressor effect of retinoblastoma protein (Rb) and p27Kip1. Detection of cyclin D1 may be used as a highly specific marker of MCL because it is expressed in virtually all of these tumors, but in only a few reported cases of aggressive variants of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and a small percentage of cases of multiple myeloma. Aggressive variants have additional genetic alterations, including inactivation of p53 and p16INK4a tumor-suppressor genes. Clinically, MCL presents in elderly males with advanced disease and frequent extranodal involvement, particularly with involvement of bone marrow, gastrointestinal tract, and spleen. The clinical evolution is relatively aggressive, with poor response to conventional therapeutic regimens and a median survival duration of 3 to 4 years. Further studies are needed to define better new therapeutic strategies for the management of these patients.
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PMID:Mantle-cell lymphoma. 1031 80

B-chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of long-lived CD5(+) B lymphocytes. We have analyzed the effect in vitro of the combination of fludarabine with cyclophosphamide and/or mitoxantrone on cells from 20 B-CLL patients. Mafosfamide, the active form of cyclophosphamide in vitro, increased the cytotoxicity of fludarabine in all of the patients studied and produced a significant synergistic effect (P <.01) after 48 hours of incubation. The addition of mitoxantrone to this combination increased the cytotoxic effect in cells from 8 patients, but in the remaining 12 patients no significant increase was observed. The effect of fludarabine and mafosfamide was dose-dependent. Mafosfamide and fludarabine had a synergistic effect in inducing apoptosis of B-CLL cells as determined by DNA staining with propidium iodide and analysis of phosphatidylserine exposure. Mafosfamide significantly increased the apoptosis induced by fludarabine on CD19(+) cells (P =.007), but not on CD3(+) cells (P =. 314). Cell viability was correlated with a decrease in Mcl-1 levels and an increase in p53 levels. These results support that fludarabine in combination with cyclophosphamide and/or mitoxantrone can be highly effective in the treatment of B-CLL.
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PMID:In vitro evaluation of fludarabine in combination with cyclophosphamide and/or mitoxantrone in B-cell chronic lymphocytic leukemia. 1051 87

We describe here two patients with mantle cell lymphoma (MCL) who after a few years, developed to the diffuse large cell lymphoma (DLCL) (anaplastic centrocytic lymphoma) growing in a diffuse sheets without the classical MCL component. In both the initial and second biopsy specimens, in each case, tumor cells were positive for cyclin D1, sIgM, sIgD, and CD5, but were negative for CD10 and CD23. In a study of immunoglobulin heavy chain (IgH) gene rearrangement, using the polymerase chain reaction (PCR) method, the products obtained from each paired biopsy tissue sample were the same size, and in one case had an identical sequence to the non-mutated VH gene. Immunohistochemistry was used to examine the expression of p53, p27Kip1 and cyclin E. Interestingly, there was clear overexpression of p53 protein in case 1 but not in case 2, compared with other typical MCL cases. The expression of p27Kip1 in the second biopsies of each case was decreased compared with those in the initial biopsies. In case 2, however, p27Kip1 was clearly expressed in the first and second biopsies, in contrast to other typical MCL cases. Thus these 2 cases demonstrate not only that the variant form of MCL may arise de novo, but also that MCL may transform to DLCL at the time of relapse. Although the mechanism of tumor progression/transformation is still poorly understood, the overexpression of p53 or p27Kip1 may be linked to a cellular mechanism involved in the development of the variant form of MCL.
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PMID:Expression of cell cycle regulating proteins in an unusual transformation of mantle cell lymphoma. 1061 57

The aim of this study was to assess the clinical significance and potential prognostic value of the expression of a panel of surface markers, proliferating, suppressor and oncogenic proteins in diffuse large B-cell lymphomas (DLBCL). Biopsies were collected from 158 patients with DLBCL and analyzed immunohistochemically for p53, p21/WAF1, bcl-2, cyclin-D1, bcl-6, mdr, CD5, CD30, epithelial membrane antigen (EMA), Ki-67 and c-myc positive tumor cells. Among these, 76 young and middle-aged patients (20-65 years) were selected to investigate the relationship between protein expression, clinical features, and survival. Survival analysis showed that advanced stage, high lactic dehydrogenase level, and high International Prognostic Index (IPI) were poor prognostic factors associated with a shorter overall survival (OS) and disease-free survival (DFS) times. A high p53 expression and low bcl-6 expression were associated with a shorter DFS time. The histological variant type, cyclin-D1+ CD5+ DLBCL, positive epithelial membrane antigen (EMA+) CD30- DLBCL, high bcl-2 expression, and low Ki-67 proliferation activity tended to be associated with worse survival, but the correlations were not statistically significant. In the multivariate analysis, the most significant factors were age, followed by IPI and last p53. The expression of p21/WAF1, mdr, and c-myc proteins did not influence OS and DFS. The expression of p53 and bcl-6 proteins may be useful prognostic indicators in DLBCL. Cyclin-D1+ CD5+ or EMA+ CD30- DLBCL tended to predict a worse survival and may probably bear a significant prognostic value worthy of consideration. Overall, clinical factors appeared to be more important than biologic parameters in determining the prognosis of diffuse large B-cell lymphomas.
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PMID:Prognostic clinicopathologic factors, including immunologic expression in diffuse large B-cell lymphomas. 1063 24

The clinical, histological, phenotypic and genotypic features of 21 primary cutaneous B-cell lymphomas (CBCLs) have been investigated. The patients were 13 men and eight women aged 34-91 years (median 67) at diagnosis. Eighteen patients had localized disease, and three had multiple skin lesions at diagnosis. Twelve patients developed cutaneous or extracutaneous recurrences, and five died from malignant lymphoma 7-84 months (median 36) after diagnosis. Histological examination showed features of marginal zone/mucosa-associated lymphoid tissue (MALT)-type lymphoma in 12 cases. Three of these had transformed to diffuse large B-cell lymphoma (DLBCL) in relapse biopsies. The remaining cases were seven primary DLBCLs and two cases tentatively classified as follicle centre cell (FCC) lymphoma. The neoplastic B cells showed similar phenotypes and genotypes in most cases (CD20+, CD79+, CD5-, CD10-, cyclin D1-, bcl-2+, bcl-x-, bax-, t(14;18)-negative). p53 protein was expressed in five cases, and four harboured mis-sense or loss-of-function mutations in the p53 gene. Deletion or promoter region hypermethylation of the p16INK4a gene was detected in two patients with DLBCL. The level of retinoblastoma protein expression and the proliferative fraction were significantly higher in DLBCL (> 50%) than in MALT- or FCC-type lymphomas (< 10%). Features associated with an unfavourable prognosis were the presence of multiple skin lesions at diagnosis, transformation from MALT-type lymphoma to DLBCL, and possibly p16INK4a aberrations. It is concluded that most CBCLs are dissimilar from FCC lymphomas and seem to be more closely related to marginal zone/MALT-type lymphomas. It is also suggested that there are fundamental differences between DLBCL and other histological categories of CBCL, indicating that cutaneous DLBCL is a separate entity with an increased growth potential and genetic features similar to DLBCL originating in other anatomical sites.
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PMID:Primary cutaneous B-cell lymphoma: a clinical, histological, phenotypic and genotypic study of 21 cases. 1080 48

We describe here two patients with mantle cell lymphoma (MCL) who after a few years, developed to the diffuse large cell lymphoma (DLCL)( anaplastic centrocytic lymphoma) growing in a diffuse sheets without the classical MCL component. In both the initial and second biopsy specimens, in each case, tumor cells were positive for cyclin D1, sIgM, sIgD, and CD5, but were negative for CD10 and CD23. In a study of immunoglobulin heavy chain (IgH) gene rearrangement, using the polymerase chain reaction (PCR) method, the products obtained from each paired biopsy tissue sample were the same size, and in one case had an identical sequence to the non-mutated VH gene. Immunohistochemistry was used to examine the expression of p53, p27(Kip1) and cyclin E. Interestingly, there was clear overexpression of p53 protein in case 1 but not in case 2, compared with other typical MCL cases. The expression of p27(Kip1) in the second biopsies of each case was decreased compared with those in the initial biopsies. In case 2, however, p27(Kip1) was clearly expressed in the first and second biopsies, in contrast to other typical MCL cases. Thus these 2 cases demonstrate not only that the variant form of MCL may arise de novo, but also that MCL may transform to DLCL at the time of relapse. Although the mechanism of tumor progression/transformation is still poorly understood, the overexpression of p53 or p27(Kip1) may be linked to a cellular mechanism involved in the development of the variant form of MCL.
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PMID:Expression of Cell Cycle Regulating Proteins in an Unusual Transformation of Mantle Cell Lymphoma. 1104 6

B-cell chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease involving more than one molecular mechanism that leads to the transformation of CD5(+) B cells at either the pregerminal or postgerminal center stage of differentiation. It was previously demonstrated that ataxia telangiectasia mutated (ATM) gene mutations can occur in B-CLL and cause a defect in the p53 pathway. Here the role of ATM mutations in the pathogenesis of B-CLL is addressed. Of 50 B-CLL tumors with fully analyzed ATM and TP53, 16 had ATM mutations. Six of 50 B-CLLs showed mutations in TP53 and the remaining 28 tumors had wild-type ATM or TP53. No tumor had both ATM and TP53 mutations. Remarkably, all 16 ATM mutant B-CLLs showed the absence of somatic variable region heavy chain hypermutation indicating a pregerminal center cell origin and a common pathogenesis for these tumors. Furthermore, in 5 of the 16 B-CLLs, ATM mutation preceded the transformation stage of differentiation. At the cellular level, ATM mutant tumors exhibited a deficient ATM-dependent p53 response to gamma irradiation, failure to up-regulate TRAIL-R2, a downstream target that links irradiation-induced p53 response with apoptosis, and an inability to repair induced chromosome breaks. Mantle cell lymphoma (MCL) is also of pregerminal center origin and ATM mutations are frequent in this malignancy. It is concluded that ATM is likely to play an important role at the pregerminal center stage and a model is proposed where loss of ATM function during B-cell ontogeny drives B-CLL tumorigenesis in pregerminal B cells by a dual defect in p53 damage response and repair of chromosome breaks.
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PMID:Ataxia telangiectasia mutated-deficient B-cell chronic lymphocytic leukemia occurs in pregerminal center cells and results in defective damage response and unrepaired chromosome damage. 1175 85

Primary cutaneous diffuse large B-cell lymphoma (DLBCL) is an uncommon lymphoma. Some authors have suggested that large B-cell lymphoma can be segregated based on anatomic site, with tumors of the lower extremity being unique. We report 15 cases of primary cutaneous DLBCL. Each case was analyzed immunohistochemically using antibodies specific for CD3, CD5, CD10, CD20, bcl-2, bcl-6, and p53. Polymerase chain reaction analysis for t(14;18)(q32;q21) also was performed. There were 13 men and 2 women (median age, 64 years). Thirteen tumors were composed predominantly of centroblasts, and 2 were immunoblastic. There was a median follow-up of 72 months. Of the 4 patients with primary cutaneous DLBCL of the lower extremity (thigh, knee, leg), 2 (50%) experienced a recurrence and 1 patient died of disease. In the non-lower extremity cases, 18% (2/11) recurred and no patients died of disease. We conclude that primary cutaneous DLBCL usually occurs in elderly patients with a male predominance. Recurrences are common, but death of disease is rare.
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PMID:Primary cutaneous diffuse large B-cell lymphoma: a clinicopathologic study of 15 cases. 1193 32

Histologically, the marginal zone pattern of the lymph node is characterized by lymphoid follicles with three distinct layers. The inner layer is composed of follicular center zones, the middle layer of darkly stained mantle zones, and the outer layer of marginal zones. However, the marginal zone pattern is rarely seen in reactive lymph nodes except for mesenteric lymph nodes. We describe the clinicopathologic, immunohistochemical and genotypic findings of six cases of reactive follicular hyperplasia exhibiting the marginal zone pattern. The patients comprised three males and three females (age range 24 to 63 years; medium 56 years). Follow-up data were obtained from five patients. None of them developed malignant lymphomas during the follow-up period of from 5 to 204 months (median 68 months). Histologically, the lesion was characterized by numerous lymphoid follicles and partial distortion of lymph node structure. Varying degrees of progressive transformation of the germinal center (PTGC) were noted in the four cases. The marginal zone pattern was observed in some or most of the lymphoid follicles including PTGC. The marginal zone B cells were small to medium-sized lymphocytes with round or slightly indented nuclei and a broad rim of pale cytoplasm. Some of them had a monocytoid appearance. They were CD20+, CD79a+, sIgM+/-, sIgD-, CD5-, CD10-, CD21-, CD23-, CD43-, CD45RO-, Bcl-6-, cyclin D1-, EMA- and p53-. A portion of them were Bcl-2 positive. Occasional large lymphoid cells with round or indented nuclei and moderate amounts of cytoplasm were observed in the marginal zone in four cases. These large lymphoid cells were usually CD20 positive, but Bcl-6 negative. A small number of them contained polytypic intracytoplasmic immunoglobulins. The polytypic nature of B lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction. Recognition of unusual marginal zone hyperplasia in reactive lymph node lesions is important to avoid confusion with nodal involvement in various low-grade B cell lymphomas presenting a marginal zone distribution pattern.
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PMID:Follicular hyperplasia presenting with a marginal zone pattern in a reactive lymph node lesion. 1207 68

To analyze the relationship between immunophenotyping profile and main clinicopathological features and outcome in diffuse large B-cell lymphoma (DLBCL), we studied 128 patients (59 men, 69 women; median age 65 years) consecutively diagnosed with de novo DLBCL in a single institution. Cells from each patient were immunostained with CD20, CD79a, CD5, CD10, bcl-6, MUM1, CD138, bcl-2, p53, p27, and Ki-67 antibodies. Four immunophenotyping profiles were distinguished according to the pattern of differentiation: germinal center-CD10(+) (GC-CD10(+); CD10(+)/Bcl-6(+)/MUM1(-)/CD138(-)), germinal center-CD10(-) (GC-CD10(-); CD10(-)/Bcl-6(+)/ MUM1(-)/CD138(-)), post-germinal center (pGC; CD10(-)/bcl-6(+/-)/ MUM1(+)/CD138(-)), and plasmablastic (CD10(-)/bcl-6(-)/MUM1(+)/CD138(+)). Rearrangement of bcl-2 was studied by polymerase chain reaction (PCR) in 57 patients. Single-antigen expression was as follows: CD5, 2%; CD10, 21%; bcl-6, 72%; MUM1, 54%; CD138, 2%; bcl-2, 59%; p53, 28%; p27, 40%. Distribution according to differentiation profiles was as follows: GC-CD10(+), 24 patients, GC-CD10-, 30 patients; pGC, 60 patients; plasmablastic, 2 patients; other patterns, 12 patients. The pGC profile was associated with primary nodal presentation and immunoblastic morphology, whereas GC-CD10(+) tumors showed disseminated disease, centroblastic morphology, bcl-2 rearrangement, and lower Ki-67 proliferative index. GC-CD10(-) patients more often presented with primary extranodal origin, early stage, normal lactic acid dehydrogenase (LDH) levels, and low or low/intermediate International Prognostic Index (IPI) scores than the others. However, no significant difference was found in terms of response or overall survival (OS) according to these profiles. Expression of bcl-2 was associated with advanced stage, high or high-intermediate IPI, and poor OS. Expression of bcl-2 maintained predictive value in multivariate analysis, with stage and LDH. In conclusion, differentiation profile was associated with particular clinicopathological features but was not essential to predicting outcome in DLBCL patients.
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PMID:Clinical impact of the differentiation profile assessed by immunophenotyping in patients with diffuse large B-cell lymphoma. 1239 66


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