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)

In this study, we analyzed the role of the p53 status for paclitaxel/Taxol sensitivity in renal cell carcinomas (RCCs) of the clear cell type. Using immunohistochemistry, nuclear p53 accumulation could not be correlated to the paclitaxel/Taxol sensitivity. DNA sequencing detected a p53 gene mutation in two out of eight RCC cell lines, i.e. in exon 8 (cell line clearCa-6), and in exon 9 (cell line clearCa-5). No correlation, however, was found between the p53 status of our RCC cell lines and their paclitaxel/Taxol sensitivity as indicated by the IC50 values. However, paclitaxel-induced growth inhibition in paclitaxel-sensitive RCC cell lines was accompanied by an increase in apoptosis, irrespective of their p53 status. Although CD95 up-regulation was observed in renal cell carcinoma with wild-type p53 upon paclitaxel treatment, paclitaxel-induced apoptosis itself is triggered independently from the CD95 system. In conclusion, the p53 status cannot predict paclitaxel/Taxol sensitivity in RCC cell lines of the clear cell type.
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PMID:Paclitaxel/Taxol sensitivity in human renal cell carcinoma is not determined by the p53 status. 1586 65

Proline oxidase is a p53-induced redox gene that can generate reactive oxygen species (ROS) and mediate apoptosis in tumor cells. We report that proline oxidase is a downstream effector in p53-mediated activation of the calcium/calmodulin-dependent phosphatase calcineurin in lung, renal, colon, and ovarian carcinoma cells. The activation of calcineurin by p53 and proline oxidase was detected by activation of the nuclear factor of activated T cells (NFAT), an established indicator of activated calcineurin. Both proline oxidase- and p53-induced activation of NFAT were sensitive to the calcineurin inhibitors cyclosporin A and FK-506, to scavengers of ROS, and to inhibitors of calcium mobilization. A proline oxidase antisense vector suppressed the ability of p53 to up-regulate proline oxidase, activate calcineurin, and induce apoptosis. Moreover, two renal carcinoma-derived mutant p53 proteins were deficient in inducing proline oxidase expression and in activating calcineurin. Inhibitors of calcineurin and calcium mobilization abolished proline oxidase-mediated apoptosis and reduced p53-induced apoptosis. Treatment of colon and ovarian carcinoma cells with the anticancer genotoxic agent etoposide up-regulated both p53 and proline oxidase, activated calcineurin, and induced apoptosis. The etoposide-mediated activation of calcineurin and induction of apoptosis was markedly suppressed by FK-506 calcineurin inhibitor. We propose that proline oxidase mediates apoptosis through the generation of proline-dependent ROS, which then mobilize calcium and activate calcineurin. The activation of calcineurin-regulated transcription factor pathways by proline oxidase might affect gene expression events important to p53 regulation of cell growth and apoptosis.
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PMID:The p53-induced gene-6 (proline oxidase) mediates apoptosis through a calcineurin-dependent pathway. 1591 62

Interferon alpha (IFN-alpha) is an approved treatment in metastatic renal cell carcinoma (RCC). The underlying mechanisms are far from being clear, but are presumed to be a combination of stimulation of cell-mediated cytotoxicity, direct antiproliferative activity and antiangiogenic effects. Recently, the role of p53 in the cellular response to IFN-alpha has been proposed in other tumor models (hepatoblastoma). We therefore studied the expression of p53 during IFN-alpha treatment using two freshly established RCC cell lines RCC5 and RCC7. While IFN-alpha treatment significantly enhanced the expression of p53 in RCC7, no changes were observed in RCC5. Cell viability under IFN-alpha remained unchanged in both cell lines. Following gamma-irradiation, a p53-activating stimulus, an enhanced cell death was observed in IFN-alpha-treated RCC7 but not in RCC5. We further demonstrate that there were no changes in Bcl-2- and Bax-expression, two target genes regulated by p53. However, intracellular staining revealed that cell death induced by IFN-alpha and gamma-irradiation was preceded by a shift of Bax to the mitochondria in RCC7. Our results suggest a role of p53 and its downstream target Bax, in the control of RCC sensitivity to IFN-alpha.
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PMID:The sensitivity of renal cell carcinoma cells to interferon alpha correlates with p53-induction and involves Bax. 1594 83

Chromophobe renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) are derived from the collecting duct epithelia, although their morphology, molecular biologic characteristics and clinical behaviors are quite different. Herein is presented a case of RCC possessing the chromophobe RCC and CDC elements occurring in a 64 year-old Japanese woman. The patient was referred to Yokohama City University Hospital with complaints of persistent back pain and fever. Radiologic examinations revealed a left renal tumor, and radical nephrectomy was performed. The patient died with multiple metastases, 8 months after the operation. The resected tumor showed an invasive growth, and its cut surface was heterogenous with hemorrhage and necrosis. Histologically, the tumor was composed of chromophobe elements with dedifferentiation, and CDC elements. The chromophobe and CDC elements had obvious histological transition. Lectin histochemistry and immunohistochemistry confirmed that this tumor was derived from the distal nephron. c-KIT, p53 and Ki67 antigen showed differential localization between the chromophobe and CDC elements, even in the transitional areas. Along with the previous reports, the present case seemed to be composite RCC derived from the collecting duct, which might present clues to elucidate carcinogenesis in the distal nephron.
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PMID:Composite distal nephron-derived renal cell carcinoma with chromophobe and collecting duct carcinomatous elements. 1594 94

Loss of p53 function is a critical event in tumor evolution. This occurs through a range of molecular events, typically a missense p53 mutation followed by loss of heterozygosity. In many cancers, there is compelling evidence that cells that can compromise p53 function have a selective advantage. The situation in renal cell carcinoma is unclear. It has recently been suggested that p53 function is unusually compromised in renal carcinoma cells by a novel dominant, MDM2/p14ARF-independent mechanism. This is hard to reconcile with other recent studies that have identified p53 as an important prognostic indicator. Indeed, one of these latter studies found that the best predictor of poor outcome was the presence of high levels of both p53 (usually indicative of p53 mutation) and MDM2. Thus, it is important that we gain a clearer understanding of the regulation of p53 and the role of MDM2 in renal cell cancer. To address this, we have investigated the transcriptional activity of p53 in a panel of renal cell carcinoma cell lines and the contribution of MDM2 and p14ARF to p53 regulation. We have found that p53 is functional in p53 wild-type renal cell carcinoma cells and that this activity is significantly regulated by MDM2 and to a much lesser extent by p14ARF. Moreover, following induction of DNA damage with UV, the p53 response in these cells is intact. Thus, future studies of renal cell carcinoma that focus on p53 and MDM2 and their role in determining disease outcome will be required to create a better understanding of this notoriously difficult to manage disease.
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PMID:p53 regulation and function in renal cell carcinoma. 1606 25

Deregulation of Wnt signalling has recently been implicated in human renal cancer. Here, we directly test this association by using a Cre-LoxP strategy to inactivate the Adenomatous Polyposis Coli (Apc) gene in the murine renal epithelium. Mice homozygous for a conditional Apc allele were intercrossed with mice transgenic for Cre recombinase under control of the Cyp1A promoter, which delivers constitutive recombination within a proportion of cells in the renal epithelium. Inactivation of Apc leads to the accumulation of nuclear beta-catenin and the rapid development of multiple dysplastic foci. Renal carcinoma was observed with an earliest onset of 4 months. This predisposition was accelerated by p53 deficiency, reducing the earliest onset to 2 months. Compared to other murine models of kidney neoplasia, this represents particularly rapid onset of disease, and so implicates an important role for Apc in suppressing renal carcinoma.
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PMID:Apc deficiency predisposes to renal carcinoma in the mouse. 1611 80

Cancer is a big problem in the developed world as well as in developing countries. Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. RCC is more common in men than in women (2:1), and it most often occurs in patients between the ages of 50-70 years. In all cancers the cancerous cells release particular kind of proteins (called tumour markers) and blood tests are used to detect the presence of these markers. These tumour markers nowadays are an area of interest for oncologists who search for a possible solution in the detection and treatment of RCC. Different kinds of biochemical and molecular markers such as ferritin, MN/CA9, apoptotic index, p53, IL-2, gamma-enolase, CD44, CD95, chromosome instability and loss of heterozygosity have been tested in RCC, but so far no marker fulfils one or the other criteria to be considered as an ideal marker for RCC. This review gives basic and updated information about the different kinds of biomarkers studied in RCC and about the role implementation of genomics and proteomics in RCC.
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PMID:Biochemical and molecular markers in renal cell carcinoma: an update and future prospects. 1619 85

Renal cell carcinomas (RCC) commonly retain wild-type but functionally inactive p53, which is repressed by an unknown dominant mechanism. To help reveal this mechanism, we screened a diverse chemical library for small molecules capable of restoring p53-dependent transactivation in RCC cells carrying a p53-responsive reporter. Among the compounds isolated were derivatives of 9-aminoacridine (9AA), including the antimalaria drug quinacrine, which strongly induced p53 function in RCC and other types of cancer cells. Induction of p53 by these compounds does not involve genotoxic stress and is mediated by suppression of NF-kappaB activity. In contrast to agents that target IkappaB kinase 2, 9AA and quinacrine can effectively suppress both basal and inducible activities of NF-kappaB, representing inhibitors of a previously undescribed type that convert NF-kappaB from a transactivator into a transrepressor, leading to accumulation of inactive nuclear complexes with unphosphorylated Ser-536 in the p65/RelA subunit. p53 function in RCC can be restored by ectopic expression of a superrepressor of IkappaB as effectively as by 9AA-derived compounds. These findings suggest that the complete or partial repression of p53 observed in many tumors can be the result of constitutive activation of NF-kappaB. The results demonstrate, in principle, the possibility to kill cancer cells selectively through simultaneous inhibition of NF-kappaB and activation of p53 by a single small molecule and suggest anticancer applications for the well known antimalaria drug quinacrine.
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PMID:Small molecules that reactivate p53 in renal cell carcinoma reveal a NF-kappaB-dependent mechanism of p53 suppression in tumors. 1628 68

We report for the first time inactivation of a tissue-specific Bcl-2 homology domain 3 (BH3)-only protein as a common aspect in human cancer. In detail, we show that loss of the BH3-only protein natural born killer (Nbk)/Bcl-2-interacting killer (Bik) is a common feature of clear-cell renal cell carcinoma (RCC). While strong Nbk expression is found in the renal tubuli and the epithelial lining of the glomerula, a consistent loss of Nbk expression was observed in primary RCC tissue and RCC cell lines. Mutation of Nbk is, however, rare, whereas deletion of the Nbk gene at 22q13.2 is frequent. In addition to loss of heterozygosity (LOH), DNA methylation mediates transcriptional silencing of the Nbk gene. The conditional restoration of Nbk/Bik expression led to apoptotic death of RCC but not of nonmalignant renal epithelia. A broader expression analysis of RCC cell lines for BH3-only proteins revealed that loss of Nbk coincides with failure to express Bim, whereas Puma, Bid and BNIP3 are readily detectable and, in case of Puma, inducible by p53. These data delineate a role for defects in BH3-only proteins as tumor suppressors in RCC and may explain at the same time the impressive clinical apoptosis resistance of RCC.
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PMID:Loss of the tissue-specific proapoptotic BH3-only protein Nbk/Bik is a unifying feature of renal cell carcinoma. 1632 56

Li-Fraumeni syndrome (LFS) is an autosomal-dominant condition characterized by early-onset sarcoma, breast cancer and other specific tumour types. In most LFS kindreds germline TP53 mutations have been identified. In general, TP53 germline mutations are not associated with late-onset common cancers. We encountered a large kindred in which a wide spectrum of tumour types occurred, including melanoma, breast, ovarian, colorectal, stomach and renal cell cancer, without clear-cut early ages at onset of disease. An Arg213Gln TP53 germline mutation was detected in 12 out of 15 affected family members whereas testing for other cancer susceptibility genes in selected patients was negative. In vitro testing indicated that the specific TP53 mutation inactivates the protein transcriptionally. Our findings suggest that this TP53 germline mutation is a causative factor in this family and that specific TP53 germline mutations can be associated with relatively late-onset common cancers.
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PMID:Late-onset common cancers in a kindred with an Arg213Gln TP53 germline mutation. 1673 87


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