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)

Given our interest in cyclic nucleotide phosphodiesterase inhibitors in chronic lymphocytic leukemia (CLL), we studied the effects of sulindac sulfone (exisulind), a non- cyclooxygenase-inhibitory end metabolite of the NSAID sulindac that has been reported to inhibit cGMP phosphodiesterases. We focused on a novel benzylamide analogue of sulindac sulfone, CP461, which is in clinical trials as a chemotherapeutic agent. As previously reported for colon carcinoma cell lines, we found that CP461 induced a rise in cGMP levels and blocked cell proliferation in the CLL cell line WSU-CLL. Surprisingly, however, cell cycle analysis revealed that CP461 caused G(2)-M arrest with an EC(50) of 1.1 micro M. G(2)-M arrest was associated with phosphorylation of Bcl2 (but not BAD, Bax, or Bcl-XL): both of these end points were abrogated by treatment with a calcium chelator. Although CP461 induces p53 up-regulation, G(2)-M arrest and Bcl2 phosphorylation were independent of p53. Because microtubule-active drugs such as vincristine also induced G(2)-M arrest and Bcl2 phosphorylation in WSU-CLL, whereas the genotoxic drugs etoposide and doxorubicin did not, we examined the effect of CP461 on microtubules by indirect immunofluoresence microscopy. CP461 eliminated microtubules rapidly, with reduction detected within 30 min of drug treatment. CP461 also induced marked changes in cell shape. Neither sulindac sulfide (a cyclooxygenase inhibitor) nor sulindac sulfone induced G(2)-M arrest, Bcl2 phosphorylation, microtubule disassembly, or cell shape changes. Treatment with 30 micro M CP461 induced greater than 50% apoptosis in 10 of 10 primary CLL leukemic cell samples, whereas the same drug concentration had only marginal effects (14% apoptosis) on whole mononuclear cells. Our work demonstrates that addition of a benzylamide moiety to sulindac compounds results in markedly altered pharmacological properties that may be of use in the therapy of lymphoid malignancies.
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PMID:Benzylamide sulindac analogues induce changes in cell shape, loss of microtubules and G(2)-M arrest in a chronic lymphocytic leukemia (CLL) cell line and apoptosis in primary CLL cells. 1238 29

Paraimmunoblastic variant of small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) is characterized by a diffuse proliferation of cells, called paraimmunoblasts, normally located on the pseudoproliferation centers. Patients usually present with multiple lymphadenopathies and a rapid and aggressive progression of the disease. We report a case with paraimmunoblastic variant of SLL/CLL genetically well-characterized by conventional cytogenetics, comparative genomic hybridization (CGH), IgH/BCL-1, IgH/BCL-2, and p53 fluorescent in situ hybridization (FISH) probes and polymerase chain reaction (PCR) for detection of IgH/BCL-2 translocation. A complex karyotype was found, with p53 deletion confirmed by CGH and FISH; however, no translocations involving either BCL-2 or BCL-1 and the immunoglobulin heavy chain gene were identified. A literature review shows only 20 previously reported cases, 6 of which involve genetic studies.
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PMID:Genetic characterization of the paraimmunoblastic variant of small lymphocytic lymphoma/chronic lymphocytic leukemia: A case report and review of the literature. 1245 22

B-cell chronic lymphoid leukemia (BCLL) is a highly heterogeneous human malignancy, presumably reflecting specific molecular alterations in gene expression and protein activity that are thought to underlie the variable disease outcome. Most B-CLL cell samples undergo apoptotic death in response to DNA damage. However, a clinically distinct aggressive subset of B-CLL is completely resistant in vitro to irradiation-induced apoptosis. We therefore addressed 2 series of microarray analyses on 4 sensitive and 3 resistant B-CLL cell samples and compared their gene expression patterns before and after apoptotic stimuli. Data analysis pointed out 16 genes whose expression varied at least 2-fold specifically in resistant cells. We validated these selected genes by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) on 7 microarray samples and confirmed their altered expression level on 15 additional B-CLL cell samples not included in the microarray analysis. In this manner, in 11 sensitive and 11 resistant B-CLL cell samples tested, 13 genes were found to be specific for all resistant samples: nuclear orphan receptor TR3, major histocompatibility complex (MHC) class II glycoprotein HLA-DQA1, mtmr6, c-myc, c-rel, c-IAP1, mat2A, and fmod were up-regulated, whereas MIP1a/GOS19-1 homolog, stat1, blk, hsp27, and ech1 were down-regulated. In some cases, the expression profile may be dependent on the status of p53. Some of these genes encode general apoptotic factors but also exhibit lymphoid cell specificities that could potentially be linked to the development of lymphoid malignancies (MIP1alpha, blk, TR3, mtmr6). Taken together, our data define new molecular markers specific to resistant B-CLL subsets that might be of clinical relevance.
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PMID:The resistance of B-CLL cells to DNA damage-induced apoptosis defined by DNA microarrays. 1258 35

Different biologic features have been associated with a more or less aggressive clinical course in chronic lymphocytic leukemia (CLL). In the present study, 20 patients with highly stable CLL observed at a single institution over a period of 10 to 23 years and who never required treatment were extensively characterized. The aim was to identify a distinct and reproducible biologic profile associated with disease stability that may be used to recognize at presentation CLL patients who are likely to have a very benign clinical course and for whom treatment is not indicated. The results obtained indicate that numerous parameters are closely associated with disease stability: a typical CLL morphology and immunophenotype, the lack of expression of the CD38 antigen, the mutated immunoglobulin (Ig) heavy (H) chain variable (V) pattern, the absence of p53 mutations, a CD4/CD8 ratio more than 1, the lack of 17p and 11q deletions and of complex karyotypic aberrations, and the occurrence of the 13q14 deletion. No case displayed the VH3-21 gene, linked in mutated CLL with a poor outcome. In addition, the VH1-69 gene associated with unmutated CLL cases was never detected. These biologic features were coupled with an indolent clinical course characterized by an unmodified clinical stage over time, and by lack of autoimmune phenomena and of major infections requiring parental antibiotics. At a time when aggressive therapeutic strategies are always more frequently used in the management of CLL, the distinctive features of patients with long-lived stable disease should be prospectively identified at presentation.
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PMID:Chronic lymphocytic leukemia patients with highly stable and indolent disease show distinctive phenotypic and genotypic features. 1267 80

As the abnormal expression of p53 protein is prognostically significant in some human cancers, its significance in patients with B-cell chronic lymphocytic leukaemia (CLL) was assessed. Two investigators evaluated the percentage of bone marrow mononuclear cells that stained for p53, using biopsies stained with anti-p53 monoclonal antibody (DO-7), and graded the degree of staining (0, +, ++, +++). Samples from a cohort of 90 patients with CLL were studied (median age 60 years, range 30-89 years; 57 patients were (63%) previously untreated, 22 patients (24%) had received one or two prior regimens, 11 patients had received (12%) three to seven regimens. The overall percentage of cells positive for p53 staining was a median of 43 (range 1-88). No investigator effect was detected either in overall percentage cells rated p53 positive or on the degree of staining (Pearson's correlation coefficient 0.980, P-value < 0.001). A Cox proportional hazards model showed that the percentage of ++ and +++ p53-positive cells correlated with various prognostic factors in CLL (P < 0.0001). A multivariate model incorporating prior therapy, Rai stage, beta2 microglobulin (beta2M) and p53 expression showed that only the percentage of p53-positive cells and beta2M were predictive of survival, and enabled the development of a highly predictive model of survival based on these two parameters.
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PMID:A prognostic model for survival in chronic lymphocytic leukaemia based on p53 expression. 1461 81

Adaphostin (NSC 680410), an analog of the tyrphostin AG957, was previously shown to induce Bcr/abl down-regulation followed by loss of clonogenic survival in chronic myelogenous leukemia (CML) cell lines and clinical samples. Adaphostin demonstrated selectivity for CML myeloid progenitors in vitro and remained active in K562 cells selected for imatinib mesylate resistance. In the present study, the mechanism of action of adaphostin was investigated in greater detail in vitro. Initial studies demonstrated that adaphostin induced apoptosis in a variety of Bcr/abl- cells, including acute myelogenous leukemia (AML) blasts and cell lines as well as chronic lymphocytic leukemia (CLL) samples. Further study demonstrated that adaphostin caused intracellular peroxide production followed by DNA strand breaks and, in cells containing wild-type p53, a typical DNA damage response consisting of p53 phosphorylation and up-regulation. Importantly, the antioxidant N-acetylcysteine (NAC) blunted these events, whereas glutathione depletion with buthionine sulfoximine (BSO) augmented them. Collectively, these results not only outline a mechanism by which adaphostin can damage both myeloid and lymphoid leukemia cells, but also indicate that this novel agent might have a broader spectrum of activity than originally envisioned.
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PMID:Involvement of reactive oxygen species in adaphostin-induced cytotoxicity in human leukemia cells. 1292 36

The genetic events involved in the transformation of chronic lymphocytic leukemia (CLL) to Richter's syndrome (RS) are poorly understood. Frequently large cells are seen in the bone marrows of patients with CLL and evidence of RS. Using a laser-capture microdissection we analyzed small and large leukemic bone marrow cells from 19 patients with RS for loss of heterozygosity (LOH) on chromosome 11 (D11S2179 at the ATM gene), 17 (D17S938 and D17S1852 at the TP53 site), and 20 (Plc1, D20S96, D20S110, and D20S119). Megakaryocytes were also isolated and used as a control for normal cells. Four of 15 (27.7%) informative cases showed LOH in small cells in the ATM gene while seven (46.7%) showed LOH in large cells. Six of 15 (40%) informative cases had LOH in chromosome 17 in small cells, and eight (53%) showed LOH in large cells. Eleven of 19 informative cases (61.1%) showed LOH in chromosome 20 in large cells, and eight (42.1%) showed LOH in small cells. RS cases with LOH at chromosome 20 were associated with marginally shorter survival rates (P = 0.08). Our data suggest that there are significant molecular differences between large and small cells in patients with CLL. Further analysis of the genes on these chromosomes may provide new insight into our understanding of the transformation of small CLL cells to large (Richter) cells.
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PMID:Molecular differences between small and large cells in patients with chronic lymphocytic leukemia. 1295 Feb 31

Abnormalities of the p53 gene are known to confer detrimental effects in chronic lymphocytic leukaemia (CLL) and are associated with short survival. We have used high dose methylprednisolone (HDMP) to treat 25 patients with advanced refractory CLL of whom 45% had p53 abnormalities shown by one or more methods: flow cytometry, fluorescent in situ hybridisation and direct DNA sequencing. Fifteen were resistant to fludarabine and 16 were non-responders to their most recent therapy. Methylprednisolone had a cytotoxic effect on lymphocytes from 95% of cases assessed by an ex vivo apoptotic drug sensitivity index (DSI). HDMP was given alone or in combination with other drugs: vincristine, CCNU, Ara-C, doxorubicin, mitoxantrone and chlorambucil, according to the results of DSI. Three patients were treated twice and each treatment was analysed separately. The overall response rate was 77% with a median duration of 12 months (range 7 -23+). Responders included 5/10 with abnormal p53, of which two achieved nodular PR. Patients with p53 abnormalities fared worse than those with normal p53. There were no differences in response according to whether HDMP was used alone or in combination. Nine of the 22 evaluable patients (3 NR and 6 PR) have died from progressive disease or transformation. Main toxicity was infection in 7/25 patients. Event free and overall survival were significantly better in responders vs non-responders ( P>0.0001 and P=0.04 respectively). Patients with a DSI of 100% to steroids had a better overall and event free survival, but this was not statistically significant. This study demonstrates that HDMP alone or in combination with other agents is a useful treatment strategy in refractory CLL including patients with p53 abnormalities.
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PMID:High dose methylprednisolone can induce remissions in CLL patients with p53 abnormalities. 1455 37

Chronic lymphocytic leukaemia (CLL) is a unique lymphoproliferative disorder that scarcely occurs under the age of 40; thereafter the incidence of CLL increases exponentially with age. CLL is characterized by progressive expansion of malignant CD5+ME+ B-cell clone accompanied by a myriad of cellular and humoral immune defects. Each of them might be linked to different clinically manifested complications such as increasing rate of infections, autoimmune disorders and disturbed immune surveillance against tumour cells. We assume that CLL occurs as a consequence of age-dependent, genetically related functional restrictions of the thymic microenvironment in supporting common lymphoid progenitor cells (CD5+ME+CD4-CD8-) to differentiate into mature T-cell and B-cell descendants. In conjunction with genetic abnormalities developing in B-cell progenitors, presumably expressing P glycoprotein (Pgp+), we postulate that developmentally altered T-cell descendants, along with quantitative imbalance among CD4+, their subsets and CD8+ lymphocytes in the peripheral blood, play an important additional role in facilitating the malignant B-cell clone emergence and in modulating the CLL clinical evolution. Namely, imbalance of any of T-cell-mediated cell interactive homeostatic mechanisms accompanied by imbalance in the production of various cytokines might in CLL influence leukaemic B-cell growth by deregulating inducer (c-myc and p53) and/or suppressor (bcl-2 and mutant p53) oncogenes responsible for the promotion or suppression of B-cell mitogenesis that may in turn further contribute to their impaired differentiation and/or differentiation arrest. In conclusion, CLL might be interpreted as a primary immunodeficiency syndrome developing in elderly population due to gradually evolving restriction of genetically controlled programs in the thymic microenvironment responsible for irregular maturation of common lymphoid progenitor cells that constitutively express CD5 antigen and ME receptor into T-cell and B-cell descendants.
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PMID:Prolegomenon for chronic lymphocytic leukaemia. 1463 14

The presence of p53 mutation or deletion predicts for poor response to conventional therapy in chronic lymphocytic leukemia (CLL). We sought to determine whether the humanized anti-CD52 antibody alemtuzumab was effective in this patient group. Thirty-six patients with fludarabine-refractory CLL were treated with alemtuzumab, 15 (42%) of whom had p53 mutations or deletions. Clinical responses in patients with p53 mutations, deletions, or both were noted in 6 (40%) of 15 versus 4 (19%) of 21 of patients without. The median response duration for this subset of patients was 8 months (range, 3-17 months). These data suggest that alemtuzumab may be an effective therapy for patients with CLL with p53 mutations or deletions.
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PMID:Alemtuzumab is an effective therapy for chronic lymphocytic leukemia with p53 mutations and deletions. 1472 85


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