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)

In this study we analysed by immunohistochemistry the expression of p53 protein in 14 malignant fibrous histocytomas (MFHs), 22 other types of sarcoma (eight leiomyosarcomas, four rhabdomyosarcomas, four liposarcomas, two fibrosarcomas, two chondrosarcomas, one malignant schwannoma, and one dermatofibrosarcoma protuberans), and 25 non-malignant mesenchymal lesions (eight dermatofibromas, four cases of nodular fasciitis, three leiomyomas, three fibromatoses, two epithelioid.leiomyomas, two neurofibromas, one schwannoma, one myositis ossificans, and one giant cell tumour of tendon sheath). Four MFHs and nine other types of sarcoma (four leiomyosarcomas, two chondrosarcomas, one liposarcoma, one fibrosarcoma, and one dermatofibrosarcoma protuberans) showed nuclear positivity for p53. Of the benign soft tissue lesions, p53 positivity was observed in two fibromatoses, one nodular fasciitis, and one dermatofibroma. The number of p53-positive cells in these benign lesions was considerably smaller than that in most of the p53-positive sarcomas. The p53 positivity in MFHs and other types of sarcoma indicates that p53 gene alterations may play a part in the neoplastic transformation of these tumours. The occurrence of p53 positivity in benign mesenchymal lesions suggests that sometimes p53 protein may accumulate in cells without an associated malignancy. Because of this, p53 immunoreactivity cannot, by itself, be used as a criterion of malignancy. According to our results, p53 positivity in over 1 per cent of tumour cells in mesenchymal lesions favours malignancy.
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PMID:p53 immunohistochemistry in malignant fibrous histiocytomas and other mesenchymal tumours. 133 24

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

Suppressor oncogene p53 is expressed more frequently in the nodular portion than the superficial spreading portion of the same melanoma. PCNA expression follows the same pattern but it is strongly expressed already in the superficial spreading portion. CD34 is found to label dermatofibrosarcoma protuberans. There is the mixture of negative strands but the immunostains are predominantly positive in the three cases studied. Neurogenic tumors are reactive but the intensity of staining is only moderate. Fibrous histiocytoma, dermatofibroma and other fibrohistiocytic tumors are non-reactive. CD34 is expressed in the outer root sheath of hair follicle below the sebaceous gland level. A case of piloepidermal cyst is CD34 positive. CD34 is expressed in vascular endothelial cells; not only hemangiomas but also lymphangiosarcoma is CD34 positive. A case of indeterminate cell histiocytosis following scabies and superficial variant of clear cell sarcoma are discussed as examples of new entities.
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PMID:Current topics of immunohistochemistry as applied to skin tumors. 769 83

An immunohistochemical method utilizing microwave oven treated avidin-biotin complex (ABC) technique was used in this study to detect P53 protein expression in 87 parafin-embedded fibrous neoplasm tissues. The results showed that the total positive staining rate was 20.7%. The positive staining rate in fibroma (FA), dermatofibrosarcoma protuberans (DFSP) fibrosarcoma (FS) and malignant fibrous histiocytoma (MFH) were 0%, 4.0%, 37.5% and 62.5% respectively. The positive staining rate of P53 protein was increased with the increase in malignancy of the neoplasma. The expression of P53 protein was not correlated with the subtypes of DFSP and MFH, but correlated with cell differentiation. Therefore, detection of P53 protein expression may have significant value in the evaluation of malignancy, metastatic potential and the prognosis of fibrous neoplasma.
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PMID:[A study of P53 protein expression in fibrous neoplasms]. 876 31

A commonly recognized feature of chronic radiation dermatitis is the presence of mesenchymal cells with large atypical nuclei known as radiation fibroblasts. Little is known about their lineage or potential for neoplastic transformation. To investigate these properties, we examined 16 biopsy specimens in which radiation fibroblasts were present with antisera to mesenchymal determinants (FXIIIa, CD34, HHF-35), a proliferation marker (Ki-67), and a tumor-suppressor protein that is overexpressed in many cancers (p53). Radiation fibroblasts were largely negative for the markers of lineage that we employed - only 2 of 16 specimens showed strong expression of FXIIIa, with weak expression in another case. Scattered radiation fibroblasts expressed CD34 in one case. HHF-35 (muscle specific actin) stained small, dendritic cells in the superficial dermis, but not radiation fibroblasts. P53 was not detected within radiation fibroblasts in any of our cases, but was overexpressed by endothelial cells in 2 cases. Ki-67 stained rare endothelial and interstitial cells but not radiation fibroblasts. Radiation fibroblasts are immunophenotypically distinct from dermal dendrocytes and myofibroblasts. They appear to be non-cycling cells, and do not express high levels of p53 despite their marked nuclear atypia. Their phenotype argues against their possible role as progenitors of atypical fibroxanthoma (AFX) and dermatofibrosarcoma protuberans (DFSP) which are associated with ionizing radiation-induced skin damage.
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PMID:An immunohistochemical analysis of radiation fibroblasts. 919 85

Abnormal expression of the 53 kDa nuclear phosphoprotein produced by the p53 gene is observed in many human cancers. p53 nuclear immunoreactivity is found commonly in tumor cells. Immunohistochemistry was performed using a monoclonal antibody, DO-7 (DAKO, Denmark; cat. no. M7001; 1:100 dilution), to investigate p53 protein immunoreactivity in a group of cutaneous fibrohistiocytic tumors that are known to be locally aggressive. The study group consisted of dermatofibrosarcoma protuberans (DFSP) (n = 14) and atypical fibroxanthoma (AFX) (n = 7). Cases of dermatofibroma (DF) (n = 16) formed the benign control group. Intense nuclear immunostaining for p53 protein was observed in 71% of DFSP and 86% of AFX. None of the dermatofibromas showed strong p53 nuclear immunostaining. Statistical analyses revealed significant differences in p53 immunoreactivity between DFSP and DF (P = 0.0001, chi 2 test) and between AFX and DF (P = 0.0001, chi 2 test). In conclusion, increased p53 protein immunoreactivity is found in DFSP and AFX but not in DF. These differences in p53 immunoreactivity suggest that increased expression of the protein may be important in the pathogenesis of the more aggressive group of fibrohistiocytic tumors.
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PMID:p53 protein immunoreactivity in fibrohistiocytic tumors of the skin. 977 Jan 92

Fibrosarcomatous (FS) change in a rare, but well-known phenomenon encountered in dermatofibrosarcoma protuberans (DFSP), and an increased chance in an adverse outcome has been suggested in patients with DFSP having FS areas (DFSP-FS). As altered p53 pathway has been suggested as having a potential role in tumour progression, we analysed the p53 gene and p53 protein together with the p53-related protein mdm2 and p21Waf1 in 5 cases of DFSP-FS and 13 of DFSP to ascertain whether the p53 pathway correlates to the fibrosarcomatous transformation of DFSP. Three of the five DFSP-FSs overexpressed p53 protein immunohistochemically, and one of them had a "missense" mutation of the p53 gene without immunohistochemical overexpression of mdm2 or p21Waf1. The other two DFSP-FSs with p53 overexpression demonstrated increased labelling indices of both mdm2 and p21Waf1. The three DFSP-FS patients with overexpression of p53 protein had frequent local recurrences, ranging from 3 to 5 in number with increasingly short intervals (mean 4.5 years), while one of the other two had no recurrences and the other, only one. None of the 13 DFSPs showed any alterations in the p53 gene or overexpressions of p53, mdm2 and p21Waf1, except for one DFSP having a "silent" mutation of the p53 gene. Three DFSPs had local recurrences once or twice with longer intervals to recurrence (mean 10.3 years). Although the number of cases examined is limited, the results suggest that alterations in the p53 pathway, such as overexpression of p53 protein by a mutated gene and mdm2 overexpression, are involved in fibrosarcomatous transformation in a subset of fibrohistiocytic tumours and possibly correlated with its more locally aggressive behaviour than that without p53 alterations or ordinary DFSP.
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PMID:Dermatofibrosarcoma protuberans with fibrosarcomatous areas. Molecular abnormalities of the p53 pathway in fibrosarcomatous transformation of dermatofibrosarcoma protuberans. 980 34

The aim of this study was the evaluation of p53/MDM-2 protein overexpression in different subtypes of human sarcomas, and their correlation with proliferative activity and patient outcome. We selected 40 cases of human sarcomas comprising 6 malignant fibrous histiocytomas (MFH), 1 fibrosarcoma, 1 dermatofibrosarcoma protuberans, 5 liposarcomas, 9 leiomyosarcomas, 1 rhabdomyosarcoma, 3 synovial sarcomas, 2 osteosarcomas, 1 chondrosarcoma, 4 Ewing's sarcomas, 2 Kaposi's sarcomas, 1 malignant haemangiopericytoma, 1 phylloides cystosarcoma, 1 neuroblastoma, 1 chordoma and 1 unclassified sarcoma. All the immunohistochemical markers, which had been used for the characterization of these sarcomas were re-examined. Additionally, the Streptavidin-Biotin peroxidase method was performed on paraffin sections using the monoclonal antibodies: anti-p53 antibody DO7, anti-MDM-2 antibody IF2 and anti-Ki-67 antibody MIB-1. According to our results, p53 protein nuclear expression was detected in 20% (8/40) of the tumours (1 fibrosarcoma, 2 liposarcomas, 1 leiomyosarcoma, 1 rhabdomyosarcoma, 2 Ewing's sarcomas and 1 unclassified sarcoma). MDM-2 nuclear staining was determined in 7.5% (3/40) of the cases (1 MFH and 2 liposarcomas). A high proliferative index was demonstrated in 27.5% (11/40) of the tumours (2 MFH, 4 leiomyosarcomas, 1 rhabdomyosarcoma, 1 osteosarcoma, 2 Ewing's sarcomas and 1 unclassified sarcoma). p53 overexpression was associated with high tumour grade (p < 0.05) and MIB-1 expression was correlated with reduced survival (p < 0.05), but p53 overexpression was not significantly associated with either MIB-1 score or with overall survival of the patients. In conclusion, from this limited and heterogeneous sample of cases, we suggest that the p53/MDM-2 pathway is involved in the tumourigenesis of several sarcoma subtypes, but it is unclear if the overexpression of these genes may become prognostic marker for patients affected with these highly aggressive tumours.
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PMID:p53/MDM-2 immunohistochemical expression correlated with proliferative activity in different subtypes of human sarcomas: a ten-year follow-up study. 989 39

Recent data indicate that reduced expression of the 17-kD protein encoded by the nm23 gene may be important in the pathogenesis of several types of human tumors. Immunohistochemistry was performed using a murine monoclonal antibody, NCL-nm23 (Novocastra, 1:150 dilution) to investigate nm23 protein immunoreactivity in a group of locally aggressive cutaneous fibrohistiocytic tumors; dermatofibrosarcoma protuberans (DFSP) (n = 14) and atypical fibroxanthoma (AFX) (n = 7). Cases of dermatofibroma (DF) (n = 17) formed the benign control group. Comparison with p53 protein immunoreactivity in the same cases studied previously was made. Strong immunohistological expression of the nm23 protein was seen in most of the cases of DF (n = 15; 88%) in the form of strong cytoplasmic immunolabelling without nuclear staining. However, strong nm23 immunoreactivity was observed in only a minority of the cases of DFSP (n = 5; 36%) and AFX (n = 2; 29%). Statistically significant differences in nm23 immunoreactivity were found between DFSP and DF (p = 0.008, chi 2 test with continuity correction) and between AFX and DF (p = 0.015; chi 2 test with continuity correction). No significant difference was seen between DFSP and AFX (p = 0.87, chi 2 test with continuity correction). There was inverse correlation between nm23 and p53 immunoreactivity (r = 0.331; r2 = 0.109; p = 0.046; simple regression analysis). In summary, nm23 protein immunoreactivity is reduced in DFSP and AFX but not in dermatofibroma suggesting that reduced expression of the protein may be important in influencing the behavior of fibrohistiocytic tumors, although this is not well characterised. nm23 protein expression is also found to be inversely related to p53 immunohistological expression in these tumors.
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PMID:nm23 protein expression and p53 immunoreactivity in cutaneous fibrohistiocytic tumors. 1039 67

The aim of this study is to evaluate the degree and spectrum of malignancy of dermatofibrosarcoma protuberans (DFSP) in the aspect of proliferative activity, flow cytometric DNA analysis, and p53 immunoreactivity. Twenty-three tumors from 19 cases of DFSP including three cases of DFSP with fibrosarcomatous areas (DFSP-FS) were studied in comparison with its allied fibrohistiocytic tumors; that is, dermatofibroma (DF; 46 cases), fibrosarcoma (FS; four cases), and malignant fibrous histiocytoma (MFH; 11 cases). MIB-1 labeling index (LI) of DFSP was significantly higher than that of DF and was lower than those of FS and of MFH. In ordinary DFSP, the recurrent tumors exhibited significantly higher MIB-1 LI than that of the primary tumors, whereas the primary tumors showed almost the same proliferative activity of DF. DFSP-FS tended to have a higher proliferative activity than DFSP without FS-area (ordinary DFSP). In five of 19 cases of DFSP, aneuploidy (near-diploidy) was found in four recurrent and one primary tumors. Immunohistochemical p53 overexpression was found in three of 19 cases of DFSP which also showed higher proliferative activity and aneuploidy. All cases of DF were immunohistochemically negative for p53, but most of the cases of FS and MFH were positive. Although DFSP has been classified in a category of fibrohistiocytic tumor of intermediate malignancy, the recurrent DFSP, DFSP-FS, and DFSP with aneuploidy and/or p53 overexpression could be a subgroup of DFSP with more aggressive clinical behavior than ordinary primary ones.
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PMID:Dermatofibrosarcoma protuberans: an analysis of proliferative activity, DNA flow cytometry and p53 overexpression with emphasis on its progression. 1050 51


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