Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

p53 is a nuclear phosphoprotein recognised as important in the regulation of normal cell growth and proliferation, the wild-type protein suppressing cell division. Expression of presumptive mutant protein, detected by immunohistochemistry, is used increasingly as a diagnostic and prognostic marker in human neoplasms. A question arises as to whether or not p53 (over)expression in a lesion is any more or less informative than other markers of cell proliferation. Twenty well-differentiated oral squamous cell carcinomas which had earlier been examined for immunoreactivity against a panel of p53 antibodies were examined for the status of cell proliferation--both in islands of invading neoplastic cells and in the non-malignant epithelial margins. The status of epithelial cell proliferation was found to be significantly higher in p53-positive tumours when enumerated by Ki-67 antibody, both within the tumour as well as its margins. This may confer a growth advantage to these neoplasms and reflect a status of inactivated p53 protein, although the actual cause of the rapid proliferation may lie in activation/inactivation of other genes. The PCNA labelling indices, on the other hand, were closely similar in both p53-positive and -negative groups, suggesting that stabilisation of p53 protein does not influence the proliferative advantage in these carcinomas via a deregulation step of PCNA-related gene products.
 ...
PMID:Association of overexpression of p53 oncoprotein with the state of cell proliferation in oral carcinoma. 793 43

Bovine subcultures (second passage) of glomerular endothelial cells (GEN) isolated from one-year-old kidney were successfully transfected by recombinant plasmids containing the simian virus (SV)-40 T antigen (Tag) using a lipofectin-mediated procedure. One cell clone was selected, propagated and characterized. This clone can be grown in RPMI 1640 medium supplemented with 10% fetal calf serum. The advantage of this cell line is the cultivation of bovine GEN without the addition of fibroblast growth factor or a coating of fibronectin or gelatin on the culture plate. More than 80 passages were achieved and the doubling time was 32 h. The Tag was easily identified in transfected-GEN by indirect immunofluorescence. These cells weakly expressed factor VIII-related antigen, slightly took up acetylated-low density lipoprotein and secreted a detectable amount of angiotensin-converting enzyme. Immunocytochemical staining for UAE-1 was also positive. Moreover, oncoproteins, such as Ki-67 and p53, were expressed in these cells. Cell cycle analysis by flow cytometry revealed that the percentages of G1, S, and G2/M stages in cycling transfected-GEN culture in RPMI 1640 medium supplemented with 10% fetal calf serum were 34%, 52.9%, and 13.1%, respectively. The conditioned medium from confluent transfected-GEN stimulated [3H]thymidine incorporation into glomerular mesangial cells. This cell line may provide a useful tool for examining modulators of mesangial cell growth. Thus this cell line is the first immortalized bovine GEN that retain the morphologic, phenotypic, and functional characteristics of bovine GEN.
 ...
PMID:Establishment and characterization of an immortalized bovine glomerular endothelial cell line. 793 62

This article summarizes the most recent developments and current practice of immunohistochemistry in the diagnosis of hematologic malignancy. Increased availability of monoclonal antibodies applicable in formaldehyde-fixed and paraffin-embedded tissue is discussed as are immunohistochemical definitions for many small cell lymphoma entities. Evaluation is made of the biologic potential of lymphomas and leukemias by the use of antibodies to proliferation antigens, such as Ki-67 and products of tumor suppressor genes (p53).
 ...
PMID:Immunohistochemical evaluation of hematologic malignancies. 796 Dec 86

BCL-2 protein plays a pivotal role in overriding programmed cell death (apoptosis), thus favouring a prolonged survival of normal and neoplastic cells. Expression of the bcl-2 gene has been documented in some human tumours (non-Hodgkin's lymphomas and prostatic adenocarcinomas), but findings in breast carcinomas have not been reported. We have used the monoclonal antibody 124 to investigate BCL-2 expression in 212 breast carcinomas, and to correlate it with the oestrogen (ER), progesterone (PR) and epidermal growth factor receptor (EGFR) status, and with other clinicopathological variables including tumour type, grade, stage, growth fraction (as evaluated by Ki-67 immunostaining), and p53 accumulation. Of the 212 carcinomas, 173 (81.6%) exhibited BCL-2 immunoreactivity in more than 25% of the neoplastic cells. BCL-2 immunoreactivity was strongly correlated with ER and PR expression (P < 0.00001), with the lobular type (P = 0.012) and with better differentiated neoplasms (P = 0.00003), whereas it was inversely correlated with EGFR (P < 0.00001), p53 (P = 0.0004) and Ki-67 (P = 0.0002) immunoreactivities. No association was found with tumour stage (T and N categories). We conclude that bcl-2 expression in breast cancers is related to the oestrogen-dependent transcription pathway.
 ...
PMID:The prevalence of BCL-2 immunoreactivity in breast carcinomas and its clinicopathological correlates, with particular reference to oestrogen receptor status. 798 3

Gangliogliomas are tumors composed of intimately admixed neuronal and glial components and account for approximately 1% of all brain tumors. Here we report the histopathological findings in 61 gangliogliomas. Epilepsy was the most common presenting symptom. Most gangliogliomas were located in the temporal lobes (74%). Thirteen percent of the gangliogliomas were associated with glioneuronal hamartias. There was considerable variation in neuronal size and density, presence of binucleated neurons, calcifications, desmoplasia, lymphocytic infiltrate, pilocytic differentiation, Rosenthal fibers, location, or histological uniformity. Fifteen percent of the gangliogliomas contained areas of purely astrocytic differentiation. All tumors were examined immunohistochemically for an aberrant p53 tumor suppressor gene product and for the presence of nuclear antigens associated with cell proliferation (Ki-67, Ki-S1, proliferating cell nuclear antigen). In 45 of 61 cases (74%) labeling indices for Ki-67 were less than 1%. Nuclear labeling for Ki-67 was observed exclusively in the astrocytic component. Gangliogliomas with very large neurons had higher Ki-67 labeling indices and occurred in younger patients than gangliogliomas with small- or intermediate-sized neurons. None of the tumors had an aberrant expression of p53. The observations suggest that gangliogliomas may arise from glioneuronal hamartias through neoplastic transformation of the astrocytic component.
 ...
PMID:Ganglioglioma: a detailed histopathological and immunohistochemical analysis of 61 cases. 798 97

Microwave oven (mwo) is used to stimulate tissue fixation and to retrieve antigens damaged by fixation. Heavy metal salt solutions, water, and citric acid buffer (cab) have been suggested for this purpose. A serie of tumors treated with cab and phosphate-buffered saline (pbs) with mwo were studied immunohistochemically with 24 antibodies. Controls were treated in the same way, except for microwaving. The antibodies were directed against antigens of the following tumors: breast and prostate carcinoma, carcinoid, lymphoma and melanoma. The results showed that cab enhanced the immunoreactivity of the following antigens: estrogen receptors (AMAC), progesterone receptors (Novocastra), HMB45, vimentin, leukocyte common antigen, PCNA, p53, MIB-1 (Ki-67) and prostatic specific antigen. The antigens that did not improve their immunoreactivity, when compared with the control series were: factor VIII, keratin, Leu 22, L26, neuron-specific enolase, CEA, chromogranin, HBME-1, smooth muscle actin and EMA. Microwaving equally improved protein S100 and desmin either with cab or pbs. The only antigen that improved with pbs was actin. The results with B72.3 and NKI/C3 were poor and not reliable. In conclusion microwaving with cab enhances the immunoreactivity of the antibodies mentioned above leading to an increase in sensibility without loosing specificity.
 ...
PMID:[Antigen retrieval by microwave oven with buffer of citric acid]. 799 28

Tumor proliferation in bladder cancer is associated with tumor behavior. To assess the association between Ki-67 labeling index (LI), p53, and c-erbB-2 overexpression, formalin-fixed tissue samples of 160 patients with transitional cell carcinoma (TCC) of the urinary bladder were studied by immunohistochemistry. Ki-67 LI was strongly associated with tumor stage (P < .0001), tumor grade (P < .0001), and p53 status (P = .0014) but not with erbB-2 overexpression (P > .2). Ki-67 LI was higher in p53-positive tumors (19%) than in p53-negative tumors (14%) when all stages were compared. Ki-67 LI was independent of p53 expression in pTa tumors (p53-positive, 9%; p53-negative, 11%), showing that p53 overexpression alone is not sufficient to induce rapid tumor cell proliferation in pTa tumors. Ki-67 LI also was independent of p53 expression in pT2 to pT4 tumors (p53-positive, 20%; p53-negative, 23%), indicating that p53 expression is not necessary for rapid tumor cell proliferation in advanced stages. However, there was a striking difference in Ki-67 LI between p53-positive pT1 tumors (22.0% +/- 8.8 standard deviation [SD]; n = 20) and p53-negative pT1 tumors (9.7 +/- 8.3 SD; n = 22; P = .0001). These results suggest that increased proliferation in p53-positive pT1 tumors is caused by additional alterations that occur during tumor progression.
 ...
PMID:p53 but not erbB-2 expression is associated with rapid tumor proliferation in urinary bladder cancer. 800 30

I examined 15 cases of differentiated adenocarcinoma of the lung which showed mutation of the p53 gene and whose primary lesions could be divided into three components (peripheral component, intermediate component and central component). Mutation of the p53 gene in each component was examined by an immunohistochemical method and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis in order to elucidate the correlation between histological types in the adenocarcinoma and mutation of the p53 gene. Furthermore, immunohistochemical detection of Ki-67 antigen and the ploidy pattern were examined for each component of the primary lesions and metastatic lesions. As a result, mutation of the p53 gene was detected mainly in the intermediate and central components, that is, in 13 cases in the intermediate component and in all cases in the central component. Higher proliferative activity as well as a DNA aneuploidy pattern were seen in these areas. In contrast, the peripheral component showed mutation of the p53 genes in only 4 cases. Lower proliferative activity and a normal diploidy pattern were seen in this area. As for the metastatic lesions, mutations of the p53 gene were detected in the metastasis of the lymph nodes and brain, as well as in the intermediate and central components of the primary lesions. Moreover, these metastatic lesions showed a higher proliferative activity which was similar index to the central or intermediate one. In 2 cases the metastasis of the lymph node showed an aneuploidy pattern as well as the intermediate and central components.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:A correlation between mutation of the p53 gene and histological heterogeneity in differentiated adenocarcinomas of the lung, with reference to stepwise progression and metastatic ability. 801 71

The p53 tumor suppressor gene is believed to play an important role in the progression of malignant tumors through mutation and overexpression. The p53 protein and Ki-67 immmunochemistry were performed on an early gallbladder carcinoma with atypical epithelium. Overexpression of the protein was found in adenocarcinoma area with diffusely distributed positive cells (p53 index: 76 +/- 24%) and in atypical epithelial areas with foci of diffusely distributed positive cells (p53 Index: 30 +/- 14%), while the Ki-67 index was 6 +/- 4% in the adenocarcinoma areas and 6 +/- 2% in the atypical epithelial areas in each p53 measured corresponding areas. This suggest that p53 protein overexpression occurs in early carcinoma and/or atypical epithelium at least in some cases and that it is an early event in the development of gallbladder adenocarcinomas and also that the atypical epithelium may belong to carcinoma.
 ...
PMID:[An early carcinoma of the gallbladder with atypical epithelium ( a report of a case with elevated p53 expression)]. 801 2

Paraffin embedded material from 15 patients suffering from head and neck squamous cell carcinoma (HNSCC) bordered by dysplastic mucosal areas was immunohistochemically investigated for the presence of p53 protein and Ki-67 proliferation marker. p53 protein was present in 9 cases (60%), invariably in invasive cancer areas as well as in adjacent non-invasive dysplastic mucosa. Only cells exhibiting atypia contained p53 protein. Ki-67 proliferation marker was present in the basal cells of the normal epithelium and more extensive in dysplasias and HNSCC. The presence of Ki-67 closely coincided with p53 protein in the 9 cases exhibiting this. No differences in Ki-67 expression were found between p53 positive and negative cases. It is concluded that the appearance of p53 protein occurs early in carcinogenesis but that cells also may show increased proliferation without involving immunohistochemically detectable alterations in the p53 gene.
 ...
PMID:The presence of p53 protein in relation to Ki-67 as cellular proliferation marker in head and neck squamous cell carcinoma and adjacent dysplastic mucosa. 803 2


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>