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)

Colon cancer evolves through epithelial cell deregulation and inappropriate proliferation. These histopathological characteristics are exemplified in the biochemical, immunohistochemical, genetic and epigenetic elements detected within colonic mucosa. Early detection is paramount for the prevention of colon cancer deaths. Aberrant crypt foci (ACF) are thought to be the earliest identifiable neoplastic lesions in the colon carcinogenetic model. The progression of ACF to polyp and, subsequently, to cancer parallels the accumulation of several biochemical alterations and mutations whereby a small fraction of ACF evolve to colon cancer. Recent data indicate that, not uncommonly, some ACF bypass the polyp stage in their carcinogenesis thus reinforcing the importance of their early detection and our understanding of their pathogenesis. Since ACF were first detected in carcinogen-treated mice, research efforts have focused on these microscopically visible lesions both in animal and human models. ACF show variable histological features, characterized by Kudo (20) and, therefore, can be grouped into differing categories by in vivo examination with high-magnification-chromoscopic-colonoscopy (HMCC). As expected, ACF are more frequently detected in distal animal and human colons coinciding with the geographic distribution of colorectal cancer (CRC). Various proteomic (Prot) markers may be altered within ACF suggesting possible prospective pathological changes. These markers include Calreticulin, Transgelin, Serotransferrin, Triphosphate isomerase and Carbonic anhydrase II. Other markers of importance include carcinoembryonic antigen (CEA), B-catenin, placental cadherin (P-cadherin), epithelial cadherin (E-cadherin), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2) and P16INK4a. Genetic mutations of K-ras, B-Raf APC and p53 have been demonstrated in ACF as well as the epigenetic alterations of CpG island methylation. Genomic instabilities (GI), illustrated by a higher GI Index (GII), microsatellite instability (MSI), loss of heterozygosity (LOH) and defects in mismatch repair (MMR) systems, are also expressed. These transformations may lead to the identification of the earliest pathological features initiating colon tumorigenesis. In this review, the advances in ACF research as precursors of CRCs are highlighted.
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PMID:Aberrant crypt foci. 1647 86

Since inducible nitric oxide synthase (iNOS) and proximal tubule injury are known to be critical determinants of lipopolysaccharide (LPS)-induced renal failure, the role of nitric oxide (NO) in proximal tubule cell apoptosis was examined. An 18-h treatment with a combination of LPS (5 microg/ml) and interferon-gamma (IFN-gamma, 100 units/ml) synergistically induced iNOS and produced a 20-fold increase in NO generation in the TKPTS murine proximal tubule cell line. NO generation by LPS + IFN-gamma was blocked by a specific iNOS blocker, L-N6-(1-iminoethyl)-lysine (L-NIL, 1 mM). To assess the role of iNOS-derived NO in proximal tubule cell apoptosis, annexin V- and propidium iodide-labeled cells were analyzed by flow cytometry. Neither the induction of iNOS nor its inhibition produced significant apoptotic cell death in TKPTS cells. Two exogenous NO donors were used to examine the role of NO more directly in proximal tubule apoptosis. Although both sodium nitroprusside (SNP), an iron-containing, nitrosonium cation donor, and S-nitroso-N-acetylpenicillamine (SNAP), a noniron-containing, NO generator, produced a concentration-dependent increase in NO generation, only SNP increased apoptotic cell death in TKPTS cells (5.9 +/- 0.7% in control cells vs. 21.6 +/- 3.8% in SNP [500 microM]-treated cells; n = 4-9; p < 0.01). SNP-mediated tubule cell apoptosis was not dependent on the activation of caspases or p53 but was possibly related to the generation of reactive oxygen species by SNP. Thus, in TKPTS cells induction of iNOS and generation of NO by LPS does not lead to tubular epithelial cell death.
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PMID:Inducible nitric oxide synthase and apoptosis in murine proximal tubule epithelial cells. 1655 43

Esophageal carcinoma has a high incidence in India but its etiology remains unknown. In the present study the correlation between apoptosis regulatory proteins and anti-oxidant enzymes in 40 esophageal carcinoma patients was examined. Patients in one group were operated by transhiatal esophagectomy and in the second group were administered cisplatin (30 mg/m2/day) and 5-fluorouracil (5-FU) (750 mg/m2/day) daily for three days followed by surgery after four weeks of neo-adjuvant therapy (NAT). Complete pathological response was achieved in 15% of patients. Results obtained by Western blot analysis showed over-expressed p53 and COX-2 protein levels in the tumor tissues as compared to the adjoining tissue and its paired normal mucosa in both groups of patients. Immunohistochemical studies showed heterogenous p53 staining pattern with sections showing both nuclear and cytoplasmic staining with 36.8% mild, 10.5% moderate and 52.6% intense p53 immunoreactivity. Both COX-2 and iNOS immunostaining revealed 25% negative and 75% mild to strongly positive immunoreactivity. Correlation studies demonstrated a positive relationship between p53 and COX-2 (P=0.030; r = +0.70) in surgically treated patients. The association of COX-2 and p53 with various anti-oxidant enzymes showed a significantly positive correlation between COX-2 expression and catalase activity and an inverse correlation between p53 expression and superoxide dismutase and catalase activity in the tumor tissue of patients given NAT. In addition, we observed a negative trend between p53 expression levels and GPx enzyme levels in both the adjoining and tumor tissue of patients having undergone surgery as main mode of treatment.
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PMID:P53, COX-2, iNOS protein expression changes and their relationship with anti-oxidant enzymes in surgically and multi-modality treated esophageal carcinoma patients. 1657 97

In the present study, we investigated the protective mechanism of quercetin (QUE) and its glycosides, rutin (RUT) and quercitrin (QUI), on reactive oxygen species (ROS)-dependent (H(2)O(2)) and -independent (chemical anoxia) cell death in rat glioma C6 cells. Induction of HO-1 protein expression was detected in QUE- but not RUT- or QUI-treated C6 cells, and this was prevented by cycloheximide and actinomycin D. Incubation of C6 cells with QUE, but not RUT or QUI, protected C6 cells from H(2)O(2)- and chemical anoxia-induced cytotoxicity according to the MTT and LDH release assays. Apoptotic characteristics including chromatin condensation, DNA ladders, and hypodiploid cells appeared in H(2)O(2)-and chemical anoxia-treated C6 cells, and those events were significantly suppressed by adding QUE (but not RUT or QUI). Increases in caspase 3, 8, and 9 enzyme activities with decreases in pro-PARP and pro-caspase 3 protein levels and an increase in cleaved D4-GDI protein were identified in H(2)O(2)-and chemical anoxia-treated C6 cells, and these were blocked by the addition of QUE, but not by RUT or QUI. Intracellular peroxide levels increased with H(2)O(2) and decreased with chemical anoxia, and the addition of QUE reduced the intracellular peroxide levels induced by H(2)O(2). Results of an anti-DPPH radical assay showed that QUE, RUT, and QUI dose-dependently inhibited the production of DPPH radicals in vitro; however, QUE (but not RUT or QUI) prevention of DNA damage induced by OH radicals was identified with a plasmid digestion assay. Increases in phosphorylated ERK and p53 protein expressions were detected in H(2)O(2)- but not chemical anoxia-treated C6 cells, and the addition of QUE significantly blocked H(2)O(2)-induced phosphorylated ERK and p53 protein expressions. Adding the HO-1 inhibitors, SnPP, CoPP, and ZnPP, reversed the protective effect of QUE against H(2)O(2)- and chemical anoxia-induced cell death according to the MTT assay and morphological observations. Additionally, QUE exhibited inhibitory effects on LPS/TPA-induced transformation in accordance with a decrease in MMP-9 enzyme activity and iNOS protein expression in C6 cells. Taken together, the results of this study suggest that QUE exhibits an inhibitory effect on both ROS-dependent and -independent cell death, and induction of HO-1 protein expression is involved.
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PMID:Quercetin inhibition of ROS-dependent and -independent apoptosis in rat glioma C6 cells. 1664 78

Approximately 20% of human cancers are estimated to develop from chronic inflammation. Recently, the NF-kappaB pathway was shown to play an essential role in promoting inflammation-associated cancer, but the role of the JAK/STAT pathway, another important signaling pathway of proinflammatory cytokines, remains to be investigated. Suppressor of cytokine signaling-1 (SOCS1) acts as an important physiological regulator of cytokine responses, and silencing of the SOCS1 gene by DNA methylation has been found in several human cancers. Here, we demonstrated that SOCS1-deficient mice (SOCS1-/- Tg mice), in which SOCS1 expression was restored in T and B cells on a SOCS1-/- background, spontaneously developed colorectal carcinomas carrying nuclear beta-catenin accumulation and p53 mutations at 6 months of age. However, interferon (IFN)gamma-/- SOCS1-/- mice and SOCS1-/- Tg mice treated with anti-IFNgamma antibody did not develop such tumors. STAT3 and NF-kappaB activation was evident in SOCS1-/- Tg mice, but these were not sufficient for tumor development because these are also activated in IFNgamma-/- SOCS1-/- mice. However, colons of SOCS1-/- Tg mice, but not IFNgamma-/- SOCS1-/- mice, showed hyperactivation of STAT1, which resulted in the induction of carcinogenesis-related enzymes, cyclooxygenase-2 and inducible nitric oxide synthase. These data strongly suggest that SOCS1 is a unique antioncogene which prevents chronic inflammation-mediated carcinogenesis by regulation of the IFNgamma/STAT1 pathways.
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PMID:IFNgamma-dependent, spontaneous development of colorectal carcinomas in SOCS1-deficient mice. 1671 19

Intrahepatic cholangiocarcinoma (CCA) is a lethal malignancy of the biliary epithelium associated with p53 mutations, bile duct injury, inflammation, and fibrosis. Here, to validate these processes in CCA, we developed a liver cirrhosis model driven by chronic intermittent toxin exposure, which provokes bile duct injury/necrosis and proliferation, fibroblast recruitment, and progressive extracellular matrix (ECM) changes. Fibrotic changes in the matrix microenvironment, typified by increased type I and III collagens and fibroblast recruitment, were shown to stimulate biliary epithelium hyperplasia with subsequent progression to malignant intrahepatic CCA only in mice harboring a p53 mutant allele. These murine CCAs bear histologic and genetic features of human intrahepatic CCA, including dense peritumoral fibrosis, increased inducible nitric oxide synthase, nitrotyrosine, and cyclooxygenase-2 expression, c-Met activation, cErbB2 overexpression, down-regulation of membrane-associated E-cadherin, and p53 codon 248 mutation. Thus, p53 deficiency, chronic bile duct injury/proliferation, and the fibrotic matrix microenvironment cooperate to induce intrahepatic CCA, highlighting the key role of the ECM microenvironment in this common liver cancer.
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PMID:Chronic bile duct injury associated with fibrotic matrix microenvironment provokes cholangiocarcinoma in p53-deficient mice. 1681 35

The apoptotic death of putaminal neurons and glia in a patient with hereditary ferritinopathy is studied immunohistochemically with antibodies to p53, activated caspase-3, PUMA, BAX, cytochrome c, and inducible nitric oxide synthase. In addition to the overexpression of ferritin and the iron accumulations assumed to result from the genetically incompetent ferritin molecule, additional contributions to the iron, heme, and hyaline deposits in this disease are sought with antibodies to 2 recently discovered globins in humans, neuroglobin and cytoglobin. The "pathognomonic" swollen to vacuolated nuclei are immunoreactive for both p53 and activated caspase-3, indicating the intervention of the p53-mediated apoptotic pathway. The immunohistochemical demonstration of neuroglobin in the swollen nuclei and both globins in the hyaline deposits highlights the potential pathogenic importance of 2 other iron-containing proteins in this disease that is largely restricted to brain. Hereditary ferritinopathy is the first human disease in which abnormalities in these heme-containing proteins are demonstrated.
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PMID:p53-mediated apoptosis, neuroglobin overexpression, and globin deposits in a patient with hereditary ferritinopathy. 1682 58

Chronic inflammation is a recognized risk factor for human cancer at various sites because of persistent oxidative and nitrative tissue damage. Trp53+/- mice show the predisposition to tumor development, such as sarcomas and lymphomas, compared with Trp53+/+ mice. We investigated the effects of chronic inflammation, especially oxidative and nitrative stress, induced by subcutaneous implantation of a plastic plate (10 x 5 x 1 mm) as a foreign body on tumorigenesis in Trp53+/- and Trp53+/+ mice. The plastic plates were implanted at the age of about 11 weeks. Thirty out of 38 Trp53+/- mice (79%) developed sarcomas around the implant (mean time of tumor appearance was 45.8 +/- 12.0 weeks of age), whereas only one of 10 Trp53+/+ mice with an implant (10%) developed a tumor, at 56 weeks. No sarcomas developed at a sham-operation site. Two of 10 Trp53+/- mice with no implant (20%) also developed three sarcomas spontaneously at 77, 81 and 84 weeks. Increased immunostaining for markers of oxidative and nitrative stress (8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-nitroguanine and 3-nitrotyrosine) and expression of inducible nitric oxide synthase in tumor cells and inflammatory cells were detected in implant-induced sarcomas compared with spontaneous sarcomas in Trp53+/- mice. Furthermore, p53 loss of heterozygosity was observed in 26 out of 29 implant-induced sarcomas (90%). These results indicate that implanted foreign bodies significantly enhanced sarcoma development in Trp53+/- mice, and this may be associated with increased oxidaive and nitrative stress. Loss of the remaining wild-type p53 allele and loss of p53 function appears to be, at least in part, underlying molecular mechanisms during the development of sarcomas at the implantation site in Trp53+/- mice. Such implant-induced sarcoma development in Trp53+/- mice could be useful for studying molecular mechanisms and developing new strategies for chemoprevention in human carcinogenesis induced by chronic inflammation and/or foreign bodies.
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PMID:Oxidative and nitrative stress caused by subcutaneous implantation of a foreign body accelerates sarcoma development in Trp53+/- mice. 1685 22

Silibinin, derived from the milk thistle plant, Silybum marianum, has been traditionally used as an antihepatotoxic agent for the treatment of liver disease. Our preliminary study demonstrated that silibinin has protected rat cardiac myocytes against beta-adrenergic agonist isoproterenol-induced injury through resuming mitochondrial function and regulating the expression of SIRT1 and Bcl-2 family members. In this study, we investigate whether silibinin has anti-apoptotic effect on isoproterenol-treated rat cardiac myocytes. DNA damage, detected by the TUNEL and DNA fragmentation assay, was diminished after treatment of silibinin. Results of nitrite and Western blot assays showed that the amount of NO and the expression of iNOS were decreased after treatment with silibinin, while the expression of procaspase-3 and digestion of caspase-3 substrates, the inhibitor of caspase-activated DNase (ICAD) and poly-(ADP-ribose) polymerase (PARP), were increased simultaneously. The DNA damage was reversed by down-regulation of p53 phosphorylation after treatment with silibinin. Result of flowcytometric analysis showed that the cell cycle was not affected, and the expression of cell cycle regulatory protein p21 also had no change. Consequently, silibinin protected cardiac myocytes against isoproterenol-induced DNA damage through caspase pathway and the expression of p53, but independent on regulation of cell cycle.
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PMID:Silibinin protects rat cardiac myocyte from isoproterenol-induced DNA damage independent on regulation of cell cycle. 1694 6

Cancer gene therapy that utilizes toxic transgene products requires strict transcriptional targeting to prevent adverse normal tissue effects. We report on the use of a promoter derived from the cyclin dependent kinase inhibitor, p21((WAF1)), to control transgene expression. We demonstrate that this promoter is relatively silent in normal cells (L132, FSK, HMEC-1) compared to the almost constitutive expression obtained in tumour cells (DU145, LNCaP, HT29 and MCF-7) of varying p53 status, a characteristic that will be important in gene therapy protocols. In addition, we found that the p21((WAF1)) promoter could be further induced by both external beam radiation (up to eight-fold in DU145 cells), intracellular-concentrated radionuclides ([(211)At]MABG) (up to 3.5-fold in SK-N-BE(2c) cells) and hypoxia (up to four-fold in DU145 cells). We have previously achieved significant radiosensitization of tumour cells both in vitro and in vivo by using inducible nitric oxide synthase (iNOS) gene therapy to generate the potent radiosensitizer, nitric oxide (NO(.-)). Here, we report that a clinically relevant schedule of p21((WAF1))-driven iNOS gene therapy significantly sensitized both p53 wild-type RIF-1 tumours and p53 mutant HT29 tumours to fractionated radiotherapy. Our data highlight the utility of this p21((WAF1))/iNOS-targeted approach.
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PMID:p21((WAF1))-mediated transcriptional targeting of inducible nitric oxide synthase gene therapy sensitizes tumours to fractionated radiotherapy. 1700 46


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