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)

Cisplatin is a platinum-containing chemotherapeutic drug that has been widely used to treat various human cancers. It acts by forming inter- and intracross-links of DNA, which is believed to be a major cause for its therapeutic efficacy. However, little attention has been paid to the effect of cisplatin on death ligand-induced cell death. Here we demonstrate that cisplatin inhibits death ligand-induced cell death in cell lines in a p53-independent manner. This inhibitory effect of cisplatin on cell death is direct, whereby cisplatin forms a complex with caspases leading to their inactivation. The cisplatin-caspase complex is reversed by the addition of reducing agent dithiothreitol, and caspase activity is regained. In addition, cisplatin shows a death-inhibition effect in in vivo animal models of fulminant liver damage induced by Fas activation and lipopolysaccharide-induced liver shock mediated by tumor necrosis factor-alpha. Together, we demonstrate that cisplatin inhibits cell death induced by death ligands in cell lines and in mice through caspase inactivation.
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PMID:Cisplatin inactivation of caspases inhibits death ligand-induced cell death in vitro and fulminant liver damage in mice. 1563 86

Cisplatin is one of the most potent and widely used anti-cancer agents in the treatment of various solid tumors. However, the development of resistance to cisplatin is a major obstacle in clinical treatment. Several mechanisms are thought to be involved in cisplatin resistance, including decreased intracellular drug accumulation, increased levels of cellular thiols, increased nucleotide excision-repair activity and decreased mismatch-repair activity. In general, the molecules responsible for each mechanism are upregulated in cisplatin-resistant cells; this indicates that the transcription factors activated in response to cisplatin might play crucial roles in drug resistance. It is known that the tumor-suppressor proteins p53 and p73, and the oncoprotein c-Myc, which function as transcription factors, influence cellular sensitivity to cisplatin. So far, we have identified several transcription factors involved in cisplatin resistance, including Y-box binding protein-1 (YB-1), CCAAT-binding transcription factor 2 (CTF2), activating transcription factor 4 (ATF4), zinc-finger factor 143 (ZNF143) and mitochondrial transcription factor A (mtTFA). Two of these-YB-1 and ZNF143-lack the high-mobility group (HMG) domain and can bind preferentially to cisplatin-modified DNA in addition to HMG domain proteins or DNA repair proteins, indicating that these transcription factors may also participate in DNA repair. In this review, we summarize the mechanisms of cisplatin resistance and focus on transcription factors involved in the genomic response to cisplatin.
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PMID:Cisplatin resistance and transcription factors. 1572 Feb 58

The aim of the study was to investigate the early effect of Transplatin (the stereo-isomer of Cisplatin) on oncogenes in inbred CBA/Ca mice. Cisplatin is commonly used for the treatment of squamous cell carcinomas of the head and neck. Cisplatin has a strong oncogene activation effect compared to the structural analogue Transplatin. Body weight equivalent amounts of a human dose of Transplatin were administered intra-peritoneally to 6- to 8-week-old, inbred, female CBA/Ca mice. Twenty-four, 48 and 72 hours after the treatment, RNA was isolated from the target organs and the expressions of c-myc, Ha-ras and p53 genes were examined. Investigation of early changes showed no significant overexpression compared to Cisplatin, which had a significant effect on oncogene expression in the "short-term" in vivo test system.
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PMID:Early effects of transplatin on oncogene activation in vivo. 1573 45

Childhood adrenocortical tumors (ACT) are very aggressive endocrine neoplasms whose incidence is quite low. Little is known about their pathogenesis, clinical presentation, and optimal treatment. In recent years, however, new information has been derived from the International Pediatric Adrenocortical Tumor Registry (IPACTR), and new clues to its pathogenesis have emerged. To provide an overview of the available data that may apply to pediatric ACT, we reviewed the epidemiology, pathogenesis, and treatment of ACT in adults and in children. Germline TP53 mutation is almost always the predisposing factor in childhood ACT. A unique germline mutation (TP53-R337H) has been described in Southern Brazil, where the incidence of ACT is 10-15 times the general incidence. Childhood ACT typically present during the first 5 years of life and has female predominance. Hormone hyperproduction is almost universal, and most patients present with virilization. Two-thirds of patients have resectable tumors. Surgery is the definitive treatment for ACT, and a curative complete resection should always be attempted. Cisplatin-based chemotherapy with mitotane is indicated for unresectable or metastatic disease, although its impact on overall outcome is slight. In childhood ACT, age, tumor size, and tumor resectability are the most important prognostic indicators. Outcome is stage-dependent; patients with small, resectable tumors have survival rates in excess of 80%, whereas the outcome for patients with unresectable disease is dismal. Patients with large, resectable tumors have an intermediate outcome. Childhood ACT are rare, but their unique epidemiology appear to implicate novel oncogenic pathways that are unique to the pediatric population. Multi-institutional and prospective studies are necessary to further our understanding of the pathogenesis and to improve outcomes.
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PMID:Biology, clinical characteristics, and management of adrenocortical tumors in children. 1574 38

The aim of this study was to determine the effect of ZD1839 on growth and apoptosis in SCC-15 (a human head and neck cancer cell line) lone, or in combination with cisplatin. High expression of the epidermal growth factor receptor has been implicated in the development of squamous cell carcinomas of head and neck. ZD1839 ('Iressa') is an orally active, selective epidermal growth factor receptor tyrosine kinase inhibitor that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Here, growth arrest was observed with 3.64 microm ZD1839. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (sMTT) viability assay revealed a significant decrease (P < 0.001) in the percentage of surviving cells upon treatment with ZD1839 and cisplatin compared with cisplatin or ZD1839 on their own. Combined therapy of 3.64 microm ZD1839 for 24 h, prior to administration of 100 microm cisplatin, significantly (P < 0.001) and additively increased the cytotoxicity effect of cisplatin. p53-independent apoptosis was seen with cisplatin treatment, a novel finding. These data support the use of ZD1839 in anti-cancer therapy, and particularly in combination therapy. Cisplatin may induce p53-independent apoptosis. Over-expression of Bcl-2 in head and neck squamous cell carcinoma tumour cell lines is unlikely to be a general mechanism to protect these cells from apoptosis.
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PMID:The effect of ZD1839 (Iressa), an epidermal growth factor receptor tyrosine kinase inhibitor, in combination with cisplatin, on apoptosis in SCC-15 cells. 1584 52

Non-small cell lung cancer (NSCLC) often shows intrinsic multidrug resistance, which is one of the most serious problems in cisplatin-based adjuvant chemotherapy. Anticancer drugs exert at least part of their cytotoxic effect by triggering apoptosis. In order to understand the molecular alterations leading to heterogeneous cisplatin sensitivity and apoptosis inducibility in NSCLC cells, we analyzed various apoptotic pathways, including the activation of caspase-8, -9 and -3, the release of cytochrome c from mitochondria and the expression levels of pro- and anti-apoptotic proteins such as Bax, Bad, Bcl-2, Bcl-xL, Fas and p53 using heterogeneously apoptosis-sensitive cells (Ma-10, Ma-31 and Ma-46). Cisplatin treatment induced the activation of caspase-8, -9 and -3 and the release of cytochrome c in apoptosis-sensitive Ma-46. The expression of Bcl-xL was the highest and p53 was not expressed in apoptosis-resistant Ma-31, and Fas was not expressed in Ma-46. These expression levels were not correlated with the apoptosis inducibility of the three cell lines. These results suggest that blockage of the apoptotic signal from mitochondria is responsible for apoptosis resistance in NSCLC cell lines. Our findings also indicate that anti-apoptotic Bcl-xL and pro-apoptotic p53 are necessary but not sufficient for resistance to cisplatin-induced apoptosis in NSCLC cells.
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PMID:Defects in apoptotic signal transduction in cisplatin-resistant non-small cell lung cancer cells. 1587 Sep 47

In head and neck cancer including hypopharyngeal cancer, cisplatin and 5-fluorouracil (5-FU) usually have been used as neoadjuvant chemotherapeutic agents. We investigated the effects of cisplatin, 5-FU and radiation on p53 protein expression and cell responses (cell cycle arrest and/or apoptosis) in the hypopharyngeal carcinoma cell line (PNUH-12; mutant type p53). PNUH-12 cells were treated with cisplatin, 5-FU and radiation. The changes in the cells were assessed by a cell cytotoxicity assay, Western blotting (p53 and p21(WAF1/CIP1) proteins), a DNA fragmentation assay, propidium iodide (PI) staining and DNA flow cytometry. The expression of p53 protein was increased after treatment with cisplatin and 5-FU, but not radiation. The expression of p21(WAF1/CIP1) protein was increased only after treatment with 5-FU, not cisplatin or radiation. With cisplatin and radiation, we observed apoptosis both by DNA fragmentation and PI staining and increased S phase in cisplatin and G2 phase in radiation by DNA flow cytometry. But, with 5-FU, we could not observe apoptosis by DNA fragmentation and PI stain but only an increased G1 phase by DNA flow cytometry. In PNUH-12, radiation induced p53-independent apoptosis and p21(WAF1/CIP1)-independent G2-phase cell cycle arrest. Cisplatin induced p53-dependent apoptosis and p21(WAF1/CIP1)-independent S-phase cell cycle arrest and 5-FU induced p53 and p21(WAF1/CIP1)-dependent G1-phase cell cycle arrest, not apoptosis. Cisplatin and 5-FU induced p53-dependent pathways, but radiation p53-independent pathway. The cell responses by cisplatin, 5-FU and radiation were all different pathways.
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PMID:Effects of cisplatin, 5-fluorouracil, and radiation on cell cycle regulation and apoptosis in the hypopharyngeal carcinoma cell line. 1588 65

Cisplatin is a commonly used chemotherapeutic agent that has a major limitation because of its nephrotoxicity. Since cisplatin-induced renal injury is mainly confined to the S3 segment of renal proximal tubules-the primary site for renal adaptive regulation of TauT-we hypothesize that TauT functions as an anti-apoptotic gene and plays a role in protecting renal cells from drug-induced nephrotoxicity. In the present study we demonstrated that expression of TauT was significantly reduced by cisplatin (50 muM) in LLC-PK1 cells. Down-regulation of TauT by cisplatin occurs at the transcriptional level in a dose-dependent manner, as demonstrated through a reporter gene driven by the TauT promoter. It appears that cisplatin down-regulates TauT expression, at least in part, through the p53-dependent pathway, since cisplatin induces the p53 expression, which, in turn, represses TauT. Cisplatin induces apoptosis of LLC-PK1 cells in a dose-dependent manner. However, forced over-expression of TauT by stable transfection of a taurine transporter cDNA (pNCT) in LLC-PK1 cells was able to attenuate cisplatin-induced down-regulation of taurine uptake by LLC-PK1 cells and protect renal tubular cells from apoptosis. The mechanism by which TauT serves as an anti-apoptotic gene in cisplatin-induced renal injury remains to be determined, but could relate to taurine-dependent cell volume regulation.
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PMID:Regulation of TauT by cisplatin in LLC-PK1 renal cells. 1594 93

We demonstrate the role of p53-mediated caspase-2 activation in the mitochondrial release of apoptosis-inducing factor (AIF) in cisplatin-treated renal tubular epithelial cells. Gene silencing of AIF with its small interfering RNA (siRNA) suppressed cisplatin-induced AIF expression and provided a marked protection against cell death. Subcellular fractionation and immunofluorescence studies revealed cisplatin-induced translocation of AIF from the mitochondria to the nuclei. Pancaspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone or p53 inhibitor pifithrin-alpha markedly prevented mitochondrial release of AIF, suggesting that caspases and p53 are involved in this release. Caspase-2 and -3 that were predominantly activated in response to cisplatin provided a unique model to study the role of these caspases in AIF release. Cisplatin-treated caspase-3 (+/+) and caspase-3 (-/-) cells exhibited similar AIF translocation to the nuclei, suggesting that caspase-3 does not affect AIF translocation, and thus, caspase-2 may be involved in the translocation. Caspase-2 inhibitor benzyloxycarbonyl-Val-Asp-Val-Ala-Asp-fluoromethylketone or down-regulation of caspase-2 by its siRNA significantly prevented translocation of AIF. Caspase-2 activation was a critical response from p53, which was markedly induced and phosphorylated in cisplatin-treated cells. Overexpression of p53 not only resulted in caspase-2 activation but also mitochondrial release of AIF. The p53 inhibitor pifithrin-alpha or p53 siRNA prevented both cisplatin-induced caspase-2 activation and mitochondrial release of AIF. Caspase-2 activation was dependent on the p53-responsive gene, PIDD, a death domain-containing protein that was induced by cisplatin in a p53-dependent manner. These results suggest that caspase-2 activation mediated by p53 is an important pathway involved in the mitochondrial release of AIF in response to cisplatin injury.
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PMID:p53-dependent caspase-2 activation in mitochondrial release of apoptosis-inducing factor and its role in renal tubular epithelial cell injury. 1598 31

cis-diamminedichloroplatinum(II) (cisplatin) is among the most active antitumour agent used in human chemotherapy. The purpose of this review is to give an insight in several molecular mechanisms that mediate the sensitivity of cancer cells to this drug and to show how recent progress in our knowledge on some critical molecular events should lay the foundations of a more rational approach to anticancer drug design. Cisplatin is primarily considered as a DNA-damaging anticancer drug, mainly forming different types of bifunctional adducts in its reaction with cellular DNA. We will address the question of cellular activity disruption that cisplatin could cause through binding to more sensitive region of the genome such as telomeres. Cellular mechanisms of resistance to cisplatin are multifactorial and contribute to severe limitation in the use of this drug in clinics. They include molecular events modulating the amount of drug-DNA interaction, such as a reduction in cisplatin accumulation inside cancer cells or inactivation of cisplatin by thiol-containing species. Other important mechanisms acting downstream to the initial reaction of cisplatin with DNA, include an increase in adducts repair and a decrease in induction of apoptosis. Recently accumulating evidence suggest a role of the long patch DNA mismatch repair system in sensing cisplatin-damaged DNA and in triggering cell death through a c-Abl- and p73-dependent cascade; two other important pathways have been unravelled that are the mitogen-activated protein kinase cascade and the tumor suppressor p53. Several of these mechanisms underlying cisplatin resistance have been exploited to design new platinum derivatives. This issue will be covered in the present review.
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PMID:Cisplatin is a DNA-damaging antitumour compound triggering multifactorial biochemical responses in cancer cells: importance of apoptotic pathways. 1599 53


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