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)

Diffuse large B cell lymphomas (DLBLs) represent a heterogeneous collection of aggressive non-Hodgkin's lymphomas that can arise either de novo or as a result of transformation from chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphomas, or lymphomas of mucosa-associated lymphoid tissue. A small percentage of DLBLs express the CD5 antigen. The majority of these cases have evolved from a pre-existing low grade non-Hodgkin's lymphoma (Richter's syndrome). However, we identified and characterized nine CD5-positive DLBLs in which the patients did not have a previous history or concomitant evidence of chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphoma, or mucosa-associated lymphoid tissue-associated non-Hodgkin's lymphoma, suggesting that they arose de novo. All nine cases expressed CD20 and monotypic immunoglobulin, all eight cases examined expressed CD19, CD22 and CD43, eight of the nine cases expressed HLA-DR, and two of eight cases expressed CD11c. None of the cases expressed CD3, CD10, CD11b, CD21, CD23 or CD30. CD5 expression by these cells was found to be identical to that of CD5-positive B cell chronic lymphocytic leukemia by quantitative polymerase chain reaction analysis of CD5 mRNA. These nine de novo CD5-positive DLBLs exhibited clonal immunoglobulin heavy and light chain gene rearrangements but lacked integration of the Epstein-Barr virus genome and structural alterations of the bcl-1, bcl-2, c-myc, H-ras, K-ras, and N-ras proto-oncogenes and the p53 tumor suppressor gene. However, bcl-6 proto-oncogene rearrangement, which is involved in chromosome band 3q27 aberrations, was found in four cases (44.4%). This is comparable with the frequency of bcl-6 gene rearrangement in CD5-negative DLBL. In contrast, bcl-6 gene rearrangement was absent in six cases of DLBL associated with Richter's syndrome. These findings suggest that de novo CD5-positive DLBLs are genotypically similar to CD5-negative DLBLs and may be pathogenetically distinct from the DLBLs associated with Richter's syndrome.
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PMID:De novo CD5-positive and Richter's syndrome-associated diffuse large B cell lymphomas are genotypically distinct. 754 11

Relatively little progress has been made in understanding the nature of the Reed-Sternberg (RS) cell and its morphologic variants in Hodgkin disease (HD). This is primarily due to the fact that RS cells represent a minute subpopulation within HD lesions. To investigate the clonal origin of RS cells and variants, we studied 27 HD lesions obtained from 11 patients. Using an image analyzer (CAS 200) we were able to demonstrate that CD30-positive RS cells are clonal elements with unique and individualized DNA profiles and that the DNA content of any given patient RS cell population is constant over time and in different pathologic sites. Using 1, 9, 11, and X alpha satellite chromosome probes and interphase cytogenetics, we also demonstrated that RS cells obtained from different tissue samples of the same patient have a unique and often abnormal chromosomal pattern. To definitively prove the hypothesis that CD30-positive RS cells are clonal elements, we investigated the presence of point mutations within p53 gene exons 5 through 9 and found that only a single patient possessed a nonsense p53 somatic point mutation (Arg to His). This same mutation could be identified in all of his available biopsies. Altogether, these findings demonstrate that RS cells and variants in HD are clonal and represent the neoplastic elements of this entity.
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PMID:The Reed-Sternberg cells of Hodgkin disease are clonal. 793 2

Ten months following the diagnosis of Hodgkin's disease (HD), a 46-year-old woman presented cutaneous and leukemic involvement by CD30+ anaplastic large cells, from which a continuously growing, exogenous growth factor-independent T cell line was established. The cultured cells are phenotypically and genotypically T cell in type, negative for EBV, HTLV-I and HTLV-II viral sequences, and release soluble CD30 into the supernatant. Karyotype analysis disclosed several chromosomal abnormalities, but none on chromosome 5q. The involvement of the short arm of chromosome 17 prompted us to investigate the TP53 gene by means of the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis, but no alterations were found in exons 5-8.
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PMID:A CD30-positive T cell line established from an aggressive anaplastic large cell lymphoma, originally diagnosed as Hodgkin's disease. 803 14

Strong immunohistochemical reactivity for p53 tumor suppressor gene product has been reported in a variety of different human malignancies including CD30- (Ki-1) positive anaplastic large cell lymphoma (ALCL). Although high levels of p53 protein have been interpreted as abnormal, rapidly proliferating benign and neoplastic lymphoid cells may have increased p53 expression in the absence of structural alterations. On the other hand, mutations in the p53 gene can lead to a lack of p53 protein production. Structural alterations of the p53 gene have not been documented in cases of ALCL and the mechanism for an abnormal pattern of p53 expression in these lymphomas has not been elucidated. Therefore, to determine whether an altered pattern of p53 expression correlates with mutations in the p53 locus in ALCL, we analyzed the expression of p53 protein immunohistochemically, compared it with the proliferation index using monoclonal antibody Ki-67, and assessed the presence of mutations in exons 5 though 9 of the p53 gene using a single-strand conformation polymorphism assay in a panel of 17 ALCLs. Furthermore, we studied the presence of allelic deletions of chromosome 17p by restriction fragment length polymorphism analysis. We found significant levels of p53 protein expression in 12 of the 15 cases studied, but identified mutations in only one of 17 cases. An allelic deletion in chromosome 17p was identified only in the one case containing a mutated p53 gene. Whereas the case containing structural alterations in the p53 gene did have strong p53 immunoreactivity, 11 cases that lacked p53 mutations in the regions examined also had significant levels of p53. Thus, our studies indicate that strong immunohistochemical reactivity for p53 is not a reliable indicator of the presence of structural alterations of p53 gene exons 5 through 9 in ALCL.
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PMID:High levels of p53 protein expression do not correlate with p53 gene mutations in anaplastic large cell lymphoma. 810 95

Limited information is current available on the molecular and immunophenogenotypic characteristics of CD30-positive anaplastic large cell (ALC) lymphomas occurring in human immunodeficiency virus (HIV)-infected individuals. To address this issue, the authors have undertaken a combined analysis of these lymphomas in a comparison with other Epstein-Barr virus (EBV)-associated tumors in the setting of HIV infection. Twenty-one AIDS-related lymphomas, including five CD30-positive ALC and 11 small noncleaved cell (SNCC) lymphomas, and five Hodgkin's disease (HD) specimens were characterized regarding the immunophenogenotypic features, the frequency and subtype distribution of EBV (as defined by in situ hybridization [ISH], Southern blot, and a polymerase chain reaction [PCR] amplification of the EBV nuclear antigen-2 [EBNA-2] region) antigen expression (latent membrane protein-1 [LMP-1], EBNA-2, and for alterations of the tumor suppressor gene p53. Combined immunophenotypic and immunogenotypic analyses showed a derivation from anomalously matured B cells in four of five CD30-positive ALC lymphomas, whereas SNCC showed features of mature B cells; no evidence of immunoglobulin or TCR gene rearrangement could be obtained in HD cases. Combined ISH and Southern blot analyses revealed that EBV was more strictly associated with HD (five of five) and CD30-positive ALC lymphomas (four of five) than with SNCC lymphomas (four of 11). EBV-positive samples from CD30-positive ALC lymphomas carried type 1 EBV (two of two specimens tested), whereas both EBV subtypes were observed in SNCC lymphomas and HD samples. All three forms of viral latent gene expression were found in the EBV positive CD30-positive ALC lymphomas. SNCC specimens did not express LMP-1 or EBNA-2, whereas HD specimens expressed LMP-1 (four of five tested) but no EBNA-2. Immunostaining for ZEBRA was consistently negative. HHV-6 DNA sequences were detected by PCR in one SNCC of the 19 specimens analyzed. Three out of five CD30-positive ALC lymphoma specimens and six of 10 SNCC showed nuclear staining for p53. No mutation was detected in any of the three CD30-positive Alc lymphoma analyzed, whereas an aberrant SSCP pattern was found in all the four SNCC samples tested. At variance with SNCC lymphomas, AIDS-related B-cell CD30- positive ALC lymphomas are strictly associated with EBV infection and may also express the broad lymphoblastoid cell line-like (LMP-1-positive, EBNA-2-positive) pattern, and lack p53 genetic lesions. Unlike EBV, HHV-6 probably does not represent a relevant factor involved in the pathogenesis of CD30-positive ALC and other HIV related lymphomas.
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PMID:Immunophenotypic and molecular analyses of acquired immune deficiency syndrome-related and Epstein-Barr virus-associated lymphomas: a comparative study. 861 54

Expression of the Epstein-Barr virus (EBV) gene product LMP1 is found in tumour cells in varying proportions of Hodgkin's disease (HD) cases. It is not clear which cellular genes are influenced by EBV in HD. A total of 387 HD cases were tested for differences among LMP1-positive and -negative cases with respect to age, sex, histotype and immunophenotypic parameters (CD2, CD3, CD4, CD15, CD19, CD20, CD21, CD22, CD23, CD25, CD30, CD43, CD45RA, CD45R0, CD70, HLA-DR, T-cell receptor beta-chain, and p53 expression). Comparison of patient age and sex as well as distribution of histotype and tumour cell immunophenotype with published data suggests that the cases in this study are representative of the spectrum of HD in developed countries. LMP1 expression was found in 131/387 HD cases (36.4 per cent) with non-homogeneous distribution among HD histotypes, the mixed cellularity type (HDmc) being most frequently EBV-associated (71/129 cases, 55 percent). No relationship was found to age and sex. Significant phenotypic differences were restricted to the HDmc histotype, where the tumour cells expressed the activation marker CD30 in a larger proportion, and CD20 in a smaller proportion, when harbouring EBV. These results suggest that EBV may influence the tumour cell phenotype in HD.
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PMID:Phenotypic modulation of Hodgkin and Reed-Sternberg cells by Epstein-Barr virus. 869 46

p21WAF1 (wild-type p53-activated fragment 1) is involved in the control of mammalian cell cycle through the binding and inhibition of cyclin-dependent kinases (Cdk). Because the product of WAF1 gene is a potent downstream effector of the p53 tumor-suppressor gene function, its pattern of cellular expression might correlate with nuclear accumulation of p53-encoded protein and/or p53 gene mutations occurring in malignant lymphomas. To investigate this issue, we analyzed immunohistochemically the expression of p53 and p21WAF1 proteins in tissue involved by non-Hodgkin's lymphomas (NHLs;253 cases) of various histologic types. In a proportion of them (80 cases), we also investigated the possible presence of p53 gene mutations using single-strand conformation polymorphism analysis and direct DNA sequencing. The absence of both p21WAF1 and p53 proteins was observed in 147 of 217 cases (67.7%) among CD30-NHL and in only 8 of 36 (22.2%) CD30+cases, which were mostly anaplastic large-cell lymphomas. A consistent number (> 10%) of p21WAF1-expressing cells was shown in 48 of 253 (18.9%) NHL cases, with a higher incidence in CD30+cases (25/36 [69.4%]), which mostly (21/36) coexpressed p53. These latter cases were characterized by a germline configuration of the p53 gene. In 50 of 253 NHL samples (19.7%), 47 of which (21.6%) belong to the CD30-group, neoplastic cells were p53+/p21-. In all of these cases, the p53+cells accounted for more than 50% of neoplastic cells, up to 100%. Point mutations of p53 gene were solely observed in all investigated cases with this latter phenotype. Our findings strongly suggest that the combined immunohistochemical evaluation of p53 and p21WAF1 is a valuable means of assessing the functional status of the p53 tumor-suppressor gene product in NHL with potential application in the monitorage and prognostication of individual cases.
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PMID:p21/WAF1 cyclin-kinase inhibitor expression in non-Hodgkin's lymphomas: a potential marker of p53 tumor-suppressor gene function. 891 68

Hodgkin's disease (HD) is characterized by the presence of the typical, clonal malignant Hodgkin and Reed-Sternberg (H-RS) cells in a hyperplastic background of normal reactive lymphocytes, plasma cells, histiocytes, neutrophils, eosinophils and stromal cells. The neoplastic nature of HD is based on aggressive clinical progression, presence of the proliferating and atypical H-RS cells, aneuploidy and cellular clonality. Immunophenotypical studies have demonstrated frequent expression of lymphoid "activation markers' including CD15, CD25, CD30, CD40, CD54, CD70, CD71, CD80, CD86 and MHC class II and less frequent expression of T- or B-cell-associated antigens by the neoplastic H-RS cells. The clonality of H-RS cells is demonstrated by clonal EBV integration, clonal cytogenetic abnormalities including p53 mutations and clonal immunoglobulin rearrangements in some HD cases. There is involvement of diverse molecules with oncogenic potential, including presence of viruses (Epstein-Barr virus and human herpes virus-6) and/or oncogenes/tumour suppressor genes (bcl-2/bcl-x, p53/MDM-2, c-myc, c-fms, N-ras, lck). The histopathological presentation and characteristic clinical features of HD correlate with an unbalanced production of multiple cytokines and define HD as a tumour of cytokine-producing cells. The proportion of malignant H-RS cells to reactive cellular components and fibrosis is dependent on the production of particular cytokines and allows subtyping of HD cases. The combined use of immunohistochemical, biochemical and molecular techniques has thus allowed recognition that HD represents more than one clinico-pathological entity with different types of H-RS cells. The defined mechanism for the biological nature, origin and oncogenesis of H-RS cells remains not fully understood, but is susceptible to further analysis using modern technology.
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PMID:Pathophysiology of Hodgkin's disease: functional and molecular aspects. 892 38

The roles of the bcl-2 and p53 proteins in Hodgkin's disease (HD) are poorly understood. We therefore compared their detected presence in Hodgkin and Reed-Sternberg/large atypical (H-RS/LA) cells immunohistochemically with the percentages of these cells double-labeled for CD30 and DNA strand breaks (DNA fragmentation index, DFI); mitotic indices (MI); and the EBV infection status. We found a highly significant inverse correlation between the fractions per case of H-RS/LA cells expressing bcl-2/p53 proteins and the DFI of CD30+ elements. No marked effect of these two oncoproteins on MI was noticed, although these parameters and DFI of CD30+ cells were linearly related. EBV infection of H-RS/LA cells exerted only a limited effect on the parameters tested. The results of this study suggest that overexpressed bcl-2 and, to some extent, p53 proteins in H-RS/LA cells of HD primarily counteract deletion of these cells.
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PMID:Mitotic activity and nuclear DNA damage of large cells in Hodgkin's disease: comparison with the expression of p53 and bcl-2 proteins and the presence of Epstein-Barr virus. 913 Jun 23

Several clinical aspects are recognized in adult T cell leukemia in ATL which was initially described in 1977 : a) smoldering, b) chronic, c) lymphomatous and d) acute. Median survival time is different according to these types: not yet reached in smoldering type, 24 months in chronic type, 10 months in lymphomatous type, 6 months in acute type. The classical phenotype of this mature T-cell proliferation is CD2+, CD3+, CD5+, CD7-, CD4+, CD8-. Activation markers are expressed: CD25+, CD30 +/-, MHC class II. HTLV-1 proviral DNA is integrated in the host genome. A region of the viral genome codes for a protein tax which transactivates viral and cellular genes, especially cytokines genes. There are no specific cytogenetic abnormalities. The genetic lesions mainly involved P53 gene where mutations are detected in 25 to 30% of cases. Conventional chemotherapy is unsuccessful in acute type. New therapeutic strategies are under investigation, especially monoclonal antibodies against RIL2 and interferon alpha associated with antiretroviral (AZT) therapy.
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PMID:[T-cell leukemia-lymphoma in adults and other blood diseases in HTLV-I infection]. 913 87


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