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)

Since the nuclear accumulation of p53 protein is known to correspond well with mutation of the p53 tumor suppressor gene, the authors examined 88 primary lung cancer specimens immunohistochemically using anti-p53 mouse monoclonal antibody, pAb1801, and analyzed the relationship between the immunohistochemical results and clinicopathological features. Nuclear localization of p53 protein was found in 43/88 (49%) tumor specimens, but not in the corresponding normal lung tissues. The percentage of cases showing nuclear p53 localization varied according to the histological type. In squamous cell carcinoma, nuclear p53 localization was found in 15/26 (57%), appearing more frequently than in other histologic types. However, no obvious correlation was observed between nuclear p53 localization and patients' age, sex, history of smoking, TNM factor, degree of differentiation, or any other clinicopathological features analyzed. In adenocarcinoma, nuclear p53 localization was found in 20/46 (43%). Incidence of positive cases was significantly correlated with regional lymph node metastasis, distant metastasis, and pathological stage (P less than 0.05). These results indicate that mutation of the p53 tumor suppressor gene plays an important role in the development of primary lung cancer, and that nuclear accumulation of p53 protein is a potential prognostic factor in adenocarcinoma of the lung.
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PMID:Clinicopathological significance of nuclear accumulation of tumor suppressor gene p53 product in primary lung cancer. 154 66

The prognostic value of cell nuclear DNA content, S-phase fraction and p53 protein accumulation in esophageal squamous-cell carcinomas was studied in a consecutive series of 80 patients from a high-incidence region of southern Thailand, who underwent esophagectomy between 1983 and 1993. Flow cytometry was used to determine tumor ploidy, DNA index and S-phase fraction, while p53 protein accumulation was evaluated immunohistochemically using the monoclonal anti-p53 antibody, CO7. Biomarkers were correlated with clinico-pathologic findings and survival by univariate and multivariate analysis. p53 protein was found in 40 tumors (50%), and was associated with significantly reduced overall survival. In patients with immunopositive tumors, depth of primary tumor invasion, lymph-node status. TNM stage and tumor grade were also significant prognostic factors. Additional predictors of reduced overall survival after esophagectomy, determined by flow cytometry, included S-phase fraction above 10%, aneuploidy (DNA index 1.2-1.8) and multiploidy (DNA index > 2.2). This study further implicates p53 in the pathogenesis of esophageal squamous-cell carcinoma. Prognostic factors such as p53 protein, S-phase fraction and DNA index may be useful in stratifying patients for adjuvant therapies in future clinical trials of esophageal cancer.
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PMID:Prognostic value of DNA index, S-phase fraction and p53 protein accumulation after surgical resection of esophageal squamous-cell carcinomas in Thailand. 759 Dec 36

Alterations in the p53 tumor suppressor gene are the most frequent genetic abnormalities in human cancers. The p53 protein is present in normal cells, and is assumed to induce G1 arrest or apoptosis in the presence of DNA lesion. The mutant protein lacks this property. Squamous cell carcinomas of the head and neck (SCCHN) are related to carcinogens in tobacco and alcohol, and provide a good model of multiple-step carcinogenesis in association with DNA damage and p53-related tumorigenesis. Stabilization of the mutant p53 protein allows immunohistochemical analyses (IHC) to be routinely used to demonstrate the mutant p53 protein in tissue samples, whereas normal p53 protein is undetectable. Ninety-nine squamous cell carcinomas, 8 in situ carcinomas, 31 preneoplastic lesions and 79 normal carcinogen-exposed mucosas of the head and neck from a total of 107 patients were examined for the expression of p53 tumor suppressor gene protein. Samples were collected before treatment, and stained with p53 specific mono- and polyclonal antibodies (DO-7, Pab 1801 and 240, CM1) using an indirect immunoperoxidase technique. Proliferating cell nuclear antigen (PCNA) provided semiquantitative estimates of proliferation. The main localizations were the pharynx (64/107) and the larynx (21/107). Positive IHC detection of p53 was observed in 9% of normal-appearing carcinogen-exposed mucosas, 37% of hyperplasias, 68% of dysplasias, 75% of in situ carcinomas, and 56/99 (56.5%) of primary tumor samples. Mucosas from 15 control patients under 10 years of age were negative. There was no correlation between p53 IHC and localization, differentiation or TNM staging.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunohistochemical detection of p53 protein in preneoplastic lesions and squamous cell carcinoma of the head and neck. 761 Aug 36

Scientific research evaluates the prognostic importance of 53 expression and DNA flow cytometry controversially. To evaluate the prognostic relevance of mutant p53 protein overexpression and DNA flow cytometry in primary breast cancer we correlated these factors with the common prognostic parameters such as tumor size, lymph node status, grading, menopausal status and receptor status. Human breast cancer specimens from 180 previously untreated patients were collected and deep frozen. On each specimen DNA-analysis by Geohde's technique (Partec PAS II) and immunohistochemical evaluation of mutant p53 protein (PAb 1801 and 240, Novocastra Lab., Great Britain) were performed. Besides TNM- and histological classification, estrogen (ER)- and progesterone (PgR) receptor content was recorded. Overexpression of mutant p53 protein was found in 34 (19%) of all specimens. All these 34 tumors were aneuploid (p = 0.007), 86% of them were receptor negative (p 0.0001), 79% had a high tumor grade (p 0.0001), 73% a high S-phase-fraction (SPF) (p = 0.045) and 53% were premenopausal (p 0.0001). Tumor size and node status did not correlate significantly with p53 expression. 27 (15%) out of 180 carcinomas were diploid. There was a significant correlation between ploidy and the tumor grade (p = 0.003) and SPF (p 0.0001), but not correlation between ploidy and tumor size (p = 0.21), node status (p = 0.33) or receptor status (p = 0.18). A low SPF was predominantly found in tumors less than 2 cm in diameter (p 0.0001); no significant correlation was found between SPF, receptor status, tumor grade, node and menopausal status. Mutant p53 protein expression and DNA analysis in combination with common prognostic parameters might help to detect prognostically unfavourable subgroups of breast cancer patients.
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PMID:Mutant p53 expression and DNA analysis in human breast cancer comparison with conventional clinicopathological parameters. 776 41

Immunohistochemical detection of the p53 gene product by monoclonal antibodies has been shown to be associated with a poor clinical outcome in carcinomas of the breast and stomach. Because the prognostic relevance of p53 immunostaining in lung cancer is still under debate, we studied the expression pattern and clinical significance of such staining in 73 patients with operable non-small-cell lung cancer. p53 expression was detected on frozen sections with the use of monoclonal antibody p1801, which recognizes both the wild-type and mutant gene product (alkaline phosphatase-anti-alkaline phosphatase method). A tumor was considered p53 positive if more than 1% of the tumor cells were stained. The p53 expression pattern was compared with clinicopathologic parameters, and analysis of follow-up, based on the data of 65 patients, was done by a log rank test (median observation time, 780 days). Nuclear p53 staining was detected in 33 of 73 non-small-cell lung cancers (45.2%). Comparison with clinicopathologic parameters demonstrated that the p53 protein was detected more frequently in younger patients (younger than 50 years, p = 0.014), whereas no correlation was found with sex, tumor differentiation, tumor histologic type, or TNM stage. Surprisingly, follow-up analysis revealed that p53 staining was associated with an increased rate of disease-free survival, especially in patients with early stage tumor disease (p = 0.004) and in male patients (p = 0.023). Counter to previous studies in other solid tumors, immunocytochemical detection of p53 expression does not predict a poor clinical outcome in non-small-cell lung cancer. In early-stage lung cancer it might be associated with an improved disease-free survival, which suggests that the majority of the detected protein inherits the wild-type tumor suppressor function.
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PMID:Immunohistochemical detection of P53 protein is not associated with a poor prognosis in non-small-cell lung cancer. 777 84

p53 is a nuclear phosphoprotein which acts as a tumour suppressor factor, regulating cell growth and division. Mutations in the p53 gene appear to be the most common genetic alterations in human cancer. The aim of this study was to investigate p53 expression in laryngeal squamous cell carcinomas and to assess its role as a marker of prognostic significance. Using immunohistochemical staining techniques, a series of laryngeal carcinomas (n = 87) were examined for expression of the mutant form of p53 phosphoprotein using the monoclonal antibody PAB 1801. p53 over-expression was noted in 50 biopsies of laryngeal carcinomas (57.5%) but not in any of the non-neoplastic laryngeal mucosa which were used as the control. There was no statistical correlation between p53 immunoreactivity and the clinicopathological parameters of the cancers including: site of tumour, TNM staging, differentiation grading and tumour recurrence. These findings indicate that p53 expression is strongly associated with carcinoma cells and not with normal cells in the larynx. However, p53 expression is probably unrelated to the biological aggressiveness of these tumours.
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PMID:Over-expression of tumour suppressor gene p53 in laryngeal squamous cell carcinomas and its prognostic significance. 778 34

Between June 1990 and April 1991, 62 colorectal tumors were assessed in a prospective fashion on the basis of various tumor characteristics. Parameters included K-ras mutation, overexpression of the p53 protein, and proliferating cell nuclear cell antigen, as well as standard histopathologic examination. A multivariate analysis showed that K-ras mutation correlated with vascular invasion (P < 0.01) and hematogenous metastasis (P < 0.01). With regard to survival time, multivariate analyses using the Cox proportional hazard model suggested that status of lymph node metastasis (P < 0.01, relative risk [rr] = 7.27), TNM stage (P < 0.05, rr = 5.37), lymphatic invasion (P < 0.05, rr = 4.48), and K-ras mutation (P < 0.06, rr = 3.69) are the most independent prognostic factors. We compared the prognostic value of the molecular assays and standard TNM prognostic factors by multivariate analysis.
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PMID:Prognostic factors of colorectal cancer: K-ras mutation, overexpression of the p53 protein, and cell proliferative activity. 791 49

Lung cancer is the leading cause of cancer death in the United States. Small cell lung cancer (SCLC) accounts for 20% to 25% of all bronchogenic carcinoma and is associated with the poorest 5-year survival of all histologic types. SCLC differs in its etiologic, pathologic, biologic, and clinical features from non-SCLC, and these differences have translated to distinct approaches to its prevention and treatment. Compared with other histologic types of lung cancer, exposures to tobacco smoke, ionizing radiation, and chloromethyl ethers pose a substantially greater risk for development of SCLC. The histologic classification of SCLC has been revised to include three categories: (1) small cell carcinoma, (2) mixed small cell/large cell, and (3) combined small cell carcinoma. Ultrastructurally, SCLC displays a number of neuroendocrine features in common with pulmonary neuroendocrine cells, including dense core vesicles or neurosecretory granules. These dense core vesicles are associated with a variety of secretory products, cell surface antigens, and enzymes. The biology of SCLC is complex. The activation of a number of dominant proto-oncogenes and the inactivation of tumor suppressor genes in SCLC have been described. Dominant proto-oncogenes that have been found to be amplified or overexpressed in SCLC include the myc family, c-myb, c-kit, c-jun, and c-src. Altered expression of two tumor suppressor genes in SCLC, p53 and the retinoblastoma gene product, has been demonstrated. Cytogenetic and molecular evidence for chromosomal loss of 3p, 5q, 9p, 11p, 13q, and 17p in SCLC has intensified the search for other tumor suppressor genes with potential import in this malignancy. Bombesin/gastrin-releasing peptide, insulin-like growth factor I, and transferrin have been identified as autocrine growth factors in SCLC, with a number of other peptides under active investigation. Several mechanisms of drug resistance in SCLC have been described, including gene amplification, the recently described overexpression of multi-drug resistance-related protein (MRP), and the expression of P-glycoprotein. The classic SCLC staging system has been supplanted by a revised TNM staging system where limited disease and extensive disease are equivalent to the TNM stages I through III and stage IV, respectively. Therapeutically, recent strategies have attained small improvements in survival but significant reductions in the toxicities of chemotherapeutic regimens. Presently, the overall 5-year survival for SCLC is 5% to 10%, with limited disease associated with a significantly higher survival rate.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Small cell lung cancer: etiology, biology, clinical features, staging, and treatment. 839 98

The prognostic value of the immunohistochemical expression of p53 was evaluated in 133 patients with pancreatic cancer. Formalin-fixed paraffin-embedded specimens of ductal pancreatic adenocarcinomas retrieved at the time of operation were stained with the monoclonal antibody DO-7. Approximately half of the tumors (47%) showed a high level of p53 immunoreactivity (> or = 20% positive nuclei). No correlation was demonstrated between the level of p53 immunoreactivity and age of the patient, gender, TNM stage, resectability or site of the tumor. A high level of p53 staining was seen in a slightly smaller proportion (30%) of patients with well-differentiated tumors than in patients with moderately (50%) or poorly differentiated (50%) tumors, but the difference was not significant. In a multivariate survival analysis, stage, grade and postoperative chemotherapy emerged as independent prognostic factors. Surgical resectability, if entered instead of stage as a variable in a separate Cox model, predicted prognosis independently. In univariate analysis, the site of the tumor was also a significant prognostic variable. However, no association between the level of p53 immunoreactivity and survival in either uni- or multivariate analysis was found.
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PMID:Prognostic value of immunohistochemical expression of p53 in patients with pancreatic cancer. 860 35

The design of treatment for patients with squamous cell carcinoma of the head and neck (SCCHN) is based on prognostic factors, today essentially performance status and TNM status. It becomes increasingly important to optimise treatment and find the appropriate level of treatment and resource consumption for each patient. This can be achieved by means of complementary "biological staging' using predictive factors. A predictive factor contains prognostic information but can also be used to choose between alternative treatments. Candidate variables for prediction of the outcome of chemotherapy are tumour ploidy status, the level of circulating C1q-complexes, the level of p53 expression, and resistance/sensitivity measured by in vitro assays. Several variables and assays capable of predicting response to radiotherapy have been proposed, e.g. the surviving fraction 2 Gy (SF2), potential tumour doubling time (Tpot), and the micronucleus assay. As none of these have yet proved to be of clinical value in a prospective randomised trial, continued studies are well worthwhile.
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PMID:Predicting response to therapy of squamous cell carcinoma of the head and neck (review). 881 40


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