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)

Metallothionein (MT) is a low molecular weight, cysteine-rich, zinc-binding protein that may have a function in cellular repair processes, growth and differentiation. Using a monoclonal antibody (E9) to metallothionein, we investigated the immunohistochemical expression of MT in routinely fixed and paraffin-embedded tissue from 98 cases of female breast carcinomas. The MT expression was studied in comparison with the expression of the basement membrane (BM) antigens (type IV collagen, laminin), fibronectin, cathepsin D, adhesion molecule CD44, p53 protein, the pRb, c-erbB-2 oncoprotein, EGFR, stromelysin-1, proliferation indices (Ki-67, PCNA), steroid receptor content as well as with other conventional clinicopathological parameters of breast cancer. Strong MT expression was observed in the majority of tumour cells in 18.4% of tumours, focal MT positivity in 13.3% and almost complete lack of MT expression in 68.4% of cases (mean value 33.36 +/- 26.36). The MT expression in carcinoma cells was strongly associated with the DCIS component of the tumour (p < 0.0001). High values of MT were correlated with low steroid receptor status (p = 0.08 for ER receptor and p = 0.019 for PgR receptor content). MT positive cases were correlated with stromelysin-1 expression (p = 0.059) and cathepsin D (p = 0.058). These findings suggest that MT expression is characteristic of the early phase of breast carcinogenesis, possibly regulated by hormones, and could be a new potential prognostic marker in breast cancer.
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PMID:Immunohistochemical localization of metallothionein in human breast cancer in comparison with cathepsin D, stromelysin-1, CD44, extracellular matrix components, P53, Rb, C-erbB-2, EGFR, steroid receptor content and proliferation. 1047 Jan 61

The immunohistochemical Cathepsin D (CD) expression of tumour and stromal cells was investigated in a series of 93 human colorectal adenocarcinomas and 22 adenomas with the intention to evaluate its prognostic significance and its contribution in the metastatic potential of colorectal cancer. CD expression was correlated with the expression of extracellular matrix components (collagen type IV, laminin and fibronectin), p53 protein, pRb, bcl-2, c-erbB-2, EGFR, proliferation indices (Ki-67, PCNA) as well as with other conventional clinicopathological features. CD expression (> 10% of positive tumour cells) was observed in 60.2% of carcinomas and in 72.7% of adenomas. Stromal CD expression was detected in all cases. A statistically significant positive correlation between neoplastic cells CD and stromal cells CD (SCCD) was observed in both carcinomas and adenomas. Cancer cells CD (CCCD) was positively correlated with collagen type IV and pRb expression as well as with PCNA score. In carcinomas, SCCD expression was statistically correlated with p53 protein and pRb expression and a trend for correlation with PCNA score was found. These data suggest that Cathepsin D of cancer and stromal cells, especially in combination with other markers, may provide more information about the biological behaviour of colorectal cancer.
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PMID:Immunohistochemical evaluation of cathepsin D expression in colorectal tumours: a correlation with extracellular matrix components, p53, pRb, bcl-2, c-erbB-2, EGFR and proliferation indices. 1047 Jan 63

Chordoid glioma of the third ventricle was recently reported as a novel tumor entity of the central nervous system with characteristic clinical and histopathological features (Brat et al., J Neuropathol Exp Neurol 57: 283-290, 1998). Here, we report on a histopathological, immunohistochemical and molecular genetic analysis of five cases of this rare neoplasm. All tumors were immunohistochemically investigated for the expression of various differentiation antigens, the proliferation marker Ki-67, and a panel of selected proto-oncogene and tumor suppressor gene products. These studies revealed a strong expression of GFAP, vimentin, and CD34. In addition, most tumors contained small fractions of neoplastic cells immunoreactive for epithelial membrane antigen, S-100 protein, or cytokeratins. The percentage of Ki-67 positive cells was generally low (<5%). All tumors showed immunoreactivity for the epidermal growth factor receptor and schwannomin/merlin. There was no nuclear accumulation of the p53, p21 (Waf-1) and Mdm2 proteins. To examine genomic alterations associated with the development of chordoid gliomas, we screened 4 tumors by comparative genomic hybridization (CGH) analysis. No chromosomal imbalances were detected. More focussed molecular genetic analyses revealed neither aberrations of the TP53 and CDKN2A tumor suppressor genes nor amplification of the EGFR, CDK4, and MDM2 proto-oncogenes. Our data strongly support the hypothesis that chordoid glioma of the third ventricle constitutes a novel tumor entity characterized by distinct morphological and immunohistochemical features, as well as a lack of chromosomal and genetic alterations commonly found in other types of gliomas or in meningiomas.
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PMID:Chordoid glioma of the third ventricle: immunohistochemical and molecular genetic characterization of a novel tumor entity. 1051

Summarizing the current evidence regarding the usefulness of the previous markers for predicting patient outcome, the most promising proliferation marker for predicting patient outcome in patients with brain tumors appears to be KI-67/MIB-1. Its potential usefulness appears to be greatest (1) for grade II and III astrocytic and oligodendroglial tumors in adults, where it may potentially predict length of survival; (2) for nonpilocytic gliomas in children, where it may also potentially predict survival; and (3) for benign, completely resected meningiomas, where it may potentially predict tumor recurrence. Although MIB-1 shows potential, we do not believe there is evidence yet definitely to consider MIB-1 labeling index a predictor of prognosis in these tumors due to the lack of published prospective studies validating the preliminary findings of multiple investigators who have performed only single-center retrospective studies. We also believe that the exact use of MIB-1 labeling index as an independent prognostic indicator for any type and grade of tumor may be complex, given the fact that all of these brain tumors have multiple independent prognostic factors contributing to patient outcome, many of which are readily available clinical factors. In the present managed care environment, MIB-1 labeling should probably await demonstration that it significantly contributes to the physician's ability accurately to predict patient outcome. The presence of telomerase RNA or telomerase activity appears to correlate with degree of malignancy in multiple types of brain tumors, including gliomas; however, it currently has no use as an independent prognostic indicator of patient outcome. It may instead be a marker for malignant tumor initiation or progression. p53 and EGFR are molecular markers that show promise as prognostic indicators of recurrence-free and overall survival in patients with GBMs, but further prospective studies are needed to confirm the retrospective findings. Postsurgical evaluation of these markers is potentially helpful in planning follow-up and treatment for these patients, those patients having tumors expressing relatively high levels of these markers requiring closer follow-up and, when possible, more aggressive therapies. Despite intensive investigation into the expression of molecules regulating apoptosis in brain tumors, no evidence presently exists to support their usefulness as markers of patient outcome. This also applies to measurements of the apoptotic rate itself in human brain tumors. Our overall impression, therefore, is that despite our great desire to find the Holy Grail of patient prognosis in the measurement of a single molecular marker with a precise cut-off value, one has not been identified ... yet! If we allow ourselves to think in terms of organismal biology, it is not surprising that the attempt directly to correlate one or even five (MIB-1, telomerase, BCL-2, p53, EGFR) gene products with a phenomenon as complex as a patient's long-term survival is unrealistic. More likely, multiple pieces of clinical information (which we already know significantly impact patient outcome in patients with brain tumors) will be considered in conjunction with new, scientifically proved molecular information as it becomes available, allowing us to predict, ever more accurately, a given patient's clinical course and outcome.
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PMID:Implications of prognostic markers in brain tumors. 1057 18

Although common among adult intracranial neoplasms, pediatric malignant astrocytomas (PMAs) comprise a relatively small proportion of the brain tumors that occur in children. The scarcity of such cases generally requires that molecular analyses of PMAs are based on the utilization of paraffin-embedded material, and here we have used 39 such specimens to examine the incidence and prognostic significance of oncogene and tumor suppressor gene alterations (including amplifications of EGFR, CDK4, and MDM2 as well as inactivating mutations of CDKN2A, TP53, and PTEN) in these tumors. In general, the frequency of alteration for the genes we have studied fell within ranges that have been reported for adult astrocytomas. However, EGFR amplification, which is usually observed in approximately 40% and 15% of adult grade 4 and grade 3 astrocytomas, respectively, was not detected in any member of this series. With regard to prognosis, PTEN mutations were significantly associated with decreased survival among grade 3 and grade 4 PMA patients, a potentially important observation because neither patient age nor tumor malignancy grade was correlated with outcome for these individuals. In total, our data suggest at least one significant distinction between the genetic etiology of pediatric and adult astrocytomas and additionally reveal that analysis of PTEN mutations in PMA patients may be useful in the differential diagnosis of these tumors.
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PMID:Analysis of oncogene and tumor suppressor gene alterations in pediatric malignant astrocytomas reveals reduced survival for patients with PTEN mutations. 1063 44

Glioblastomas develop de novo (primary glioblastomas) or through progression from low-grade or anaplastic astrocytoma (secondary glioblastomas). There is increasing evidence that these glioblastoma subtypes develop through different genetic pathways. Primary glioblastomas are characterized by EGFR and MDM2 amplification/overexpression, PTEN mutations, and p16 deletions, whereas secondary glioblastomas frequently contain p53 mutations. Loss of heterozygosity (LOH) on chromosome 10 (LOH#10) is the most frequent genetic alteration in glioblastomas; the involvement of tumor suppressor genes, other than PTEN, has been suggested. We carried out deletion mappings on chromosome 10, using PCR-based microsatellite analysis. LOH#10 was detected at similar frequencies in primary (8/17; 47%) and secondary glioblastomas (7/13; 54%). The majority (88%) of primary glioblastomas with LOH#10 showed LOH at all informative markers, suggesting loss of the entire chromosome 10. In contrast, secondary glioblastomas with LOH#10 showed partial or complete loss of chromosome 10q but no loss of 10p. These results are in accordance with the view that LOH on 10q is a major factor in the evolution of glioblastoma multiform as the common phenotypic end point of both genetic pathways, whereas LOH on 10p is largely restricted to the primary (de novo) glioblastoma.
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PMID:Loss of heterozygosity on chromosome 10 is more extensive in primary (de novo) than in secondary glioblastomas. 1065 4

There are distinct genetic pathways leading to the glioblastoma, the most malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in older patients and are characterized by epidermal growth factor (EGF) receptor amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in younger patients and frequently contain p53 mutations. In this study, we assessed the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. Single-strand conformation polymorphism followed by direct DNA sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN mutations in seven cases (37%). Homozygous p16 deletion was detected by differential polymerase chain reaction in seven (37%) gliosarcomas. The overall incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive. Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the gliosarcomas showed amplification or overexpression of the EGF receptor. Thus gliosarcomas exhibit a genetic profile similar to that of primary (de novo) glioblastomas, except for the absence of EGFR amplification/overexpression. Identical PTEN mutations in the gliomatous and sarcomatous tumor components were found in two cases. Other biopsies contained p16 deletions, an identical p53 mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly supports the concept of a monoclonal origin of gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.
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PMID:Genetic profile of gliosarcomas. 1066 71

In recent years, there have been great advances in our understanding of the genetic events and the molecular biology of human brain gliomas. Cytogenetic information has suggested that a pattern of non-random abnormalities involving numerical deviations such as the gain, partial deletion, or total loss of chromosomes as well as translocations and structural rearrangements of certain chromosome lesions are characteristic features for some tumors. In addition, the somatic activation of cellular oncogenes and inactivation of tumor suppressor genes represent important genetic alterations leading to progressive disorder of normal cellular growth control mechanisms. This review describes the abnormal chromosomal and molecular abnormalities that occur during formation of brain tumors of astrocytic origin, particularly fibrillary astrocytic neoplasms. The most frequent genetic alterations include inactivation of the p53, p16, Rb and PTEN genes, and overexpression of the CDK4, EGFR and VEGF genes. Other less well defined abnormalities include aberrations in chromosomes 1, 9, 10, 11, 19 and 22.
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PMID:Cytogenetic and molecular abnormalities in astrocytic gliomas (Review). 1067 94

Permanent glioma cell lines are invaluable tools in understanding the biology of glioblastomas. The present study reports the establishment of a clonal human cell line, GBM6840, derived from a biopsy of paediatric cerebellar glioblastoma multiforme. GBM6840 had a doubling time of 32 h and grew as a monolayer of large round cells that retained immunopositivity for glial fibrillary acidic protein and vimentin. Karyotypic analysis revealed a modal chromosome number of 68 and polysomies of chromosomes 3, 5 and 20, as well as the presence of 3-4 marker chromosomes. GBM6840 also showed anchorage-independent growth in soft agar and tumour formation in nude mice. The p16(CDKN2A) gene was transcriptionally silenced by hypermethylation, consistent with the lack of protein expression observed in the original tumour and cultured cells. Western blot analysis revealed normal protein expression of pRb and CDK4. It appears that p16 is the major component altered in the cell cycle pathway and may confer these cells unrestrained proliferation potential. Neither EGFR gene amplification nor over-expression of the protein was detected in the cultured cells. Over-expression of the p53 protein was observed in the majority of cells, despite undetectable mutation (exons 5-8) in the gene. One allele of the PTEN gene was found to be mutated during in vitro cultivation. Telomerase activity was demonstrated in the cultured cells but not in the original tumour, supporting the hypothesis that telomerase is required for the in vitro immortalization process.
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PMID:Establishment and characterization of a human cell line from paediatric cerebellar glioblastoma multiforme. 1073 64

Selection of surrogate endpoint biomarkers (SEBs) and appropriate study design are two of the main challenges in evaluating potential chemopreventive agents. In a prospective random fine-needle aspiration (FNA) study of women at high risk of development of breast cancer, we previously demonstrated that cytologic evidence of epithelial hyperplasia with or without atypia, as well as abnormalities of several cellular biomarkers (DNA ploidy; immunocytochemical expression of p53, EGFR, ER, and/or Her-2/neu), were more prevalent in high-risk women than in low-risk controls. We also demonstrated that the subsequent development of breast cancer was best predicted by an initial presentation of hyperplasia with atypia, as well as by multiple biomarker abnormalities. These findings indicate that FNA cytology and biomarkers can be used to identify women who are appropriate subjects for chemoprevention trials, and can then be used as surrogate endpoint biomarkers to monitor efficacy of potential agents. An example of this use in an ongoing single-agent phase II trial is provided. Several options for study design of possible multi-agent breast cancer chemoprevention trials are discussed, depending upon the existing preclinical and clinical data, the questions being asked, and the number of eligible subjects available.
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PMID:Breast cancer chemoprevention trials using the fine-needle aspiration model. 1076 8


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