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)

p53 protein plays an important role in control of cell proliferation by suppressing proliferation of cells with DNA damage. Mutations of the p53 gene increase the stability of the encoded nonfunctional protein which accumulates in the nuclei, allowing it to be detectable by immunohistochemistry. Mutant p53 protein has been observed in preneoplastic and neoplastic conditions supporting its role in the development of some human cancers. In this immunohistochemical study, we examined p53 expression in 12 Dermatofibrosarcoma Protuberans (DFSP) and 10 Dermatofibromas (DF). Results were compared with the cellular proliferation rate by using the monoclonal antibody Mib-1 which detects Ki-67 antigen expression. Nuclear accumulation of the p53 protein was observed in 11 DFSP. All DF were negative for p53. No statistical correlation could be established between p53 and Mib-1 staining in our cases. We conclude that mutations of the p53 gene may be involved in the molecular pathogenesis of DFSP but not of DF. Mib-1 index can not be successfully used to distinguish DFSP from DF.
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PMID:Comparison of p53 expression in dermatofibrosarcoma protuberans and dermatofibroma: lack of correlation with proliferation rate. 749 69

p53 gene function and tumor cell proliferation are thought to be important parameters for tumor progression in bladder cancer. In this study immunohistochemistry and fluorescence in situ hybridization were used to determine the relationship between p53 alterations, tumor proliferation (Ki-67 Labeling Index), and numerical chromosomal aberrations in formalin fixed bladder tumors. p53 expression was associated with Ki-67 LI (p = 0.0014), polysomy 17 (p = 0.001) and polysomy 7 (p = 0.0241). This is further evidence for a significant role of the p53 gene in proliferation control and preservation of genomic stability.
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PMID:[Ki-67 fraction, p53 alteration and numerical chromosome aberrations (chromosomes 7 and 17) in formalin fixed bladder tumors]. 751 Dec 86

Using an immunohistochemical method expression of PCNA, Ki-67, 486p and p53 antigen was investigated in paraffin sections of 119 patients with primary transitional cell carcinoma of the bladder. The purpose of this study was to detect recurring G1 and G2 bladder tumours compared with non-recurrent tumours. A relative large fraction of labelled cells for PCNA and Ki-67 was found in recurring G1 and G2 carcinomas. Moreover, recurrent transitional cell carcinomas showed a more positive staining pattern for 486p and p53, in contrast to non-recurrent carcinomas. Immunohistochemistry of these four antigens seems to yield additional information about the possibility of recurrence in G1 and G2 bladder carcinomas, thus allowing early, i.e. more aggressive, therapy.
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PMID:[Monoclonal antibodies (MIB 1, PC 10, 486p and p53) as prognostic factors for recurrent urothelial carcinoma of the urinary bladder]. 751 Dec 88

Different variations of the antigen retrieval technique using different retrieval solutions have been evaluated for their effectiveness in restoring the antigenicity of six intranuclear antigens, each of which is a potentially valuable prognostic indicator in formalin-fixed, paraffin-embedded tissue sections. The results of immunohistochemical staining for estrogen receptor, progesterone receptor, androgen receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen were compared following the different antigen retrieval approaches. The strongest immunostaining signal with the clearest background was obtained by microwave heating of dewaxed paraffin sections for 10 minutes in 0.05 mol/L glycine HCl (pH 3.5) or in citrate buffer solution (pH 6). Urea solution, distilled water, and lead thiocyanate solution yielded improvements with some antigens, but less consistently and less impressively than glycine HCl buffer or citrate buffer. Following antigen retrieval nuclear staining was sharply defined and could be achieved consistently in a variety of tissues after formalin fixation for as long as 7 days. The duration of fixation, however, was an important variable; generally, the longer the fixation time the more vigorous the retrieval procedure required. This study demonstrates the ability to stain a variety of intranuclear antigens, which are not readily demonstrable otherwise, in formalin-paraffin sections with a high degree of consistency and reproducibility. The availability of methods that are effective in paraffin sections may facilitate studies of the possible value of these markers as prognostic indicators for predicting the response of major tumors to different forms of therapy. This study also provided insight into the basic principles of the antigen retrieval method, which may be helpful in attempts to develop a more uniformly standardized technique applicable to many different antigen systems.
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PMID:Strategies for improving the immunohistochemical staining of various intranuclear prognostic markers in formalin-paraffin sections: androgen receptor, estrogen receptor, progesterone receptor, p53 protein, proliferating cell nuclear antigen, and Ki-67 antigen revealed by antigen retrieval techniques. 792 19

Immunocytochemical methods are important tools for identifying antigens in tissue sections and cell smears. Some antigens were retrieved in formalin-fixed and paraffin-embedded tissues by means of a microwave technique. This method also increased the sensitivity of the immunohistochemical detection of several other antigens. Altogether, microwave boiling of the tissue sections in citrate buffer clearly improved the immunoreactivity for cytokeratin 18, oestrogen receptor, Ki-67 protein, PCNA, p53 protein, retinoblastoma gene protein and c-erbB-2 protein. This new technique, which can be applied in every pathology laboratory, will facilitate the application of immunohistochemical methods for research and diagnostic work.
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PMID:[Microwave oven in immunohistochemistry. An important tool for determination of antigens in formalin-fixed and paraffin-embedded tissue]. 752 43

The present study compared two microwave based antigen-retrieval solutions in their ability to unmask antigenic determinants in formalin-fixed and paraffin-embedded tissues for Immunostaining. In this regard, two widely used antigen-retrieval solutions, namely 0.05 M glycine-HCl buffer, pH 3.6, containing 0.01% (w/v) (EDTA) and 0.1 M sodium citrate buffer, pH 6.0, were evaluated for (1) their effectiveness in unmasking a wide range of antigenic determinants (2) their ability to yield reproducible results (3) the lack of deleterious effects in any antibody antigen systems of interest. Both of these antigen-retrieval solutions resulted in greatly improved immunostaining following microwave-heating of dewaxed tissue sections for 2 x 5 min. Glycine-HCl buffer solution resulted in stronger immunostaining with antibodies to nuclear antigens [androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), p53, proliferating cell nuclear antigen (PCNA), Ki-67 and MIB-1], cytoplasmic antigens (actin and factor-VIII) and cell-surface antigens [Cu-18, epithelial membrane antigen (EMA) and MT-1 (CD43)], whereas sodium citrate buffer yielded superior immunostaining with antibodies to vimentin, and some cell-surface antigens [common leukocyte antigen (CLA) (CD45) and UCHL-1 (CD45RO)]. The effect of unmasking the epitopes recognized by antibody to PCNA was equally effective with either of the antigen-retrieval solutions. Antibodies to pan-keratin, prostatic acid phosphatase (PAP), B lymphocyte antigen (BLA.36, CD20CY) and L26 (CD20) exhibited no enhancement in the intensity of staining with either of the antigen-retrieval solutions.
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PMID:Comparison of two microwave based antigen-retrieval solutions in unmasking epitopes in formalin-fixed tissue for immunostaining. 754 61

Histopathologic features alone fail to reliably stratify patients with clinical Stage A nonseminomatous germ cell tumors of the testis into groups with high and low risk for occult metastatic disease. Previous flow cytometric studies at Indiana University demonstrated a significant correlation between high proliferative activity and metastatic disease. The current study evaluated the prognostic significance of immunohistochemical markers related to tumor proliferation and aggressiveness in a consecutive series of clinical Stage A nonseminomatous germ cell tumors patients who underwent retroperitoneal lymph node dissection. Archival material of the orchiectomy specimens of 62 patients (45 pathologic Stage A, 17 with metastatic disease) was reviewed and immunohistochemically stained for Ki-67 antigen (MIB-1), proliferation-associated nuclear antigen (PC10), p53 protein (Pab1801), and Factor-VIII-related antigen (neovascularization). Staining with MIB-1 was significantly higher in the metastatic group (mean 80.2%, standard deviation [SD] 15.5) than in pathologic Stage A cases (66.3%, SD 27.9; P = 0.0032) and was predictive of metastatic status with a sensitivity of 82% and specificity of 69%. In this study, no patient with a MIB-1 value less than 52% had metastases. Proliferation-associated nuclear antigen and p53 staining correlated with MIB-1 values (R = 0.63 and 0.55, respectively) but did not correlate with metastatic status. Tumor angiogenesis was also not predictive of metastatic status. Assessment of proliferation rates using MIB-1 antibody in clinical Stage A nonseminomatous germ-cell-tumor patients may prove helpful in predicting metastatic status.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prognostic significance of immunohistochemical proliferation markers (Ki-67/MIB-1 and proliferation-associated nuclear antigen), p53 protein accumulation, and neovascularization in clinical stage A nonseminomatous testicular germ cell tumors. 754 14

The wild-type p53 gene suppresses cell proliferation and induces apoptosis when it is transfected into human colon cancer cell lines. Therefore, mutation of the p53 gene, which correlates closely with p53 protein overexpression, would be predicted to activate cell proliferation and limit apoptosis. We tested this hypothesis by correlating p53 protein expression with cell proliferation and apoptosis in 70 neoplasms (29 adenomas and 41 carcinomas) using p53 and Ki-67 immunohistochemical staining and DNA nick end labelling. The p53 immunoreactivity was independent of the Ki-67 positivity. The apoptotic incidence was less frequent (P < 0.005) in tumours with diffuse p53 protein overexpression than in those with the sporadic overexpression, defined as p53 staining of isolated or scattered expression. In addition, apoptotic incidence only correlated directly (P < 0.05) with Ki-67 positivity in tumours with sporadic p53-protein expression. These results indicate that p53 protein that is expressed sporadically in colorectal neoplasms is probably wild-type protein and induces apoptosis in response to active cell proliferation. In contrast, diffusely overexpressed p53 protein in colorectal neoplasms is probably mutant and correlates with a reduction in apoptotic cell death independently of cell proliferation.
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PMID:Correlation of p53 protein expression with apoptotic incidence in colorectal neoplasia. 755 42

The significance of apoptosis in human gastric carcinomas was investigated in comparison with proliferative activity and p53 accumulation, using an in situ DNA nick end labeling method and immunohistochemistry for both Ki-67 antigen and p53 protein. Apoptotic labeling indices (LI) of 51 differentiated carcinomas (21 of early and 22 of advanced stage) were significantly lower than for 33 undifferentiated tumors (9 of early and 24 of advanced stage) (P < 0.05). In both types, apoptotic LI of advanced stage lesions were significantly higher than for the early stage cases (P < 0.005, P < 0.03). The distribution of apoptotic cells was different from that of Ki-67-positive cells, generally exhibiting an inverse correlation for areas of predominance. In contrast, there was no significant correlation between p53 immunoreactivity and either apoptotic LI or Ki-67 LI. It is concluded that in human gastric carcinomas the susceptibility to apoptosis is related to tumor cell differentiation and depth of invasion, and may play a role in selection of clonal subpopulations with high growth potential.
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PMID:Apoptosis in gastric carcinomas and its association with cell proliferation and differentiation. 755 97

The treatment and prognosis of patients with cerebral astrocytic tumours are currently guided by histopathological classification. This study evaluates immunohistochemistry using Ki-67, an antibody to a nuclear protein expressed in proliferating cells, and DO-7, an antibody to the product of the tumour suppressor gene p53, as prognostic indicators for these tumours. Immunohistochemistry with Ki-67 has been correlated with the behaviour of many different tumours, but its value as a prognostic indicator in astrocytic tumours is diminished by the conflicting results of previous studies. Immunohistochemistry with antibodies to the p53 protein has been used as a prognostic indicator in melanomas and some carcinomas, but the relation between prognosis and accumulation of this protein in astrocytic tumours has not been clarified. We have tested the hypothesis that survival is correlated with Ki-67 immunolabelling indices (LIs) and patterns of p53 immunolabelling in the cerebral astrocytic tumours of a large cohort of patients (n = 123) for whom clinical indices were well documented. Astrocytic tumours were divided into three histological types: fibrillary astrocytoma (n = 24), anaplastic astrocytoma (n = 31), and glioblastoma (n = 68). Histological type and patient age were independent predictors of survival. Median Ki-67 LIs differed significantly (P < 0.0001) between the types of astrocytic tumour, and tumours with a Ki-67 LI < 2% had a significantly (P < 0.0001) better prognosis. Ki-67 LI as a continuous variable carried a significant (P = 0.0043) unadjusted hazard to survival which was lost when adjusted for other variables, notably histological type. By contrast, no relation was found between survival and three categories of p53 labeling (p53-negative, p53 LI < 40%, and p53 LI > 60%). The results indicate that, whereas Ki-67 immunohistochemistry predicts survival in patients with astrocytic tumours, conventional histological appraisal remains the best guide to prognosis, and immunohistochemistry for p53 has no value in the assessment of these tumours.
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PMID:Prognostic indicators in a range of astrocytic tumours: an immunohistochemical study with Ki-67 and p53 antibodies. 756 22


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