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)

The histological grading of 29 ductal pancreatic carcinomas was compared with that of silver stained NOR-associated proteins and with p53 immunoreactivity. The AgNOR number (NZ) and AgNOR areas (NF) of 10 grade I carcinomas, 13 grade II carcinomas and 6 grade III carcinomas were investigated by image analysis. Furthermore, the protein expression of the p53 gene was examined by immunohistochemistry. A significant difference was found in both AgNOR parameters between grade I, grade II and grade III carcinomas (NZ: p < 0.01; NF: p < 0.05; grade I carcinomas: NZ 5.1/NF 8.2 microns 2; grade II carcinomas: NZ 6.0/NF 11.3 microns 2 grade III carcinomas: NZ 8.4/NF 15.2 microns 2). By contrast no relation was found between histological grading and p53 immunoreactivity. In 56% of all carcinomas positive evidence was found of the p53 gene product. (6 grade I carcinomas, 7 grade II carcinomas, 3 grade III carcinomas). 44% of the cases were p53-negative (4 grade I carcinomas, 6 grade II carcinomas, 3 grade III carcinomas). This study demonstrates that the AgNOR technique is useful in the grading of ductal pancreatic carcinomas, whereas the expression of the p53 gene product is not.
 ...
PMID:[Histological grading of ductal pancreatic carcinomas. Relationship to silver staining of NOR-associated proteins and to p53 immunoreactivity]. 751 73

The identification of hereditary non-polyposis colorectal cancer (HNPCC) is important not only for the patient, but also for family members who are at increased risk of developing cancer. To determine if measuring various pathobiologic features of the colon carcinomas is useful in separating sporadic from HNPCC tumors, the authors studied tumor tissues from 46 patients with HNPCC and compared them to 70 with sporadic colorectal carcinoma. Parameters investigated included DNA ploidy (flow cytometry), AgNOR count (by silver staining), microvessel density (immunohistochemistry), p53 and K-ras expression, and grade-related parameters. Diploid tumors were more frequent in patients with HNPCC (65% vs 40%, P < .02), thus confirming previous observations concerning such an association. Higher AgNOR counts and greater AgNOR areas were observed in sporadic tumors than in HNPCC (5.2 +/- 1.5 vs 4.5 +/- 1.8, P < .01). Hereditary tumors tended to be less vascularized, whereas oncogene expression and grade-related parameters did not show appreciable differences between the two types of tumors. In conclusion, some of the investigated parameters may contribute to defining the biologic profile of HNPCC. In addition, these findings support the clinical impression of a more favorable outcome that is frequently seen in HNPCC patients.
 ...
PMID:Biologic characterization of hereditary non-polyposis colorectal cancer. Nuclear ploidy, AgNOR count, microvessel distribution, oncogene expression, and grade-related parameters. 753 9

Intense research using animal models has indicated that chemically-induced rat liver cancer proceeds through multiple, distinct stages that can be characterised morphologically and biochemically. Primary human liver cancer, with hepatitis B and other environmental factors such as poor nutrition and food contaminating mycotoxins as contributing etiological factors, is one of the major causes of cancer deaths in African, Asian and some Western countries. Recent advances in surgical and diagnostic techniques have also allowed the identification of potential morphological precursors of primary human liver cancer, and suggested a model consistent with the concepts of initiation--promotion--progression as in the rat. The expression of proliferating cell nuclear antigen (PCNA), silver-staining nucleolar organiser regions (AgNOR), oncogenes and the tumor suppressor gene p53 in preneoplastic and neoplastic lesions of rat and human livers is presently reviewed. This undertaking is an attempt to evaluate whether the current knowledge regarding molecular mechanisms of carcinogenesis is sufficient to permit the use of these molecular parameters as 'intermediate' markers in studies of risk assessment and cancer prevention, without having to resort to tumor appearance as an end-point.
 ...
PMID:The potential for the use of cell proliferation and oncogene expression as intermediate markers during liver carcinogenesis. 760 May 46

Uterine papillary serous adenocarcinoma (UPSC) is one of the most aggressive endometrial tumors. UPSC has been associated with an increased propensity for extrauterine spread. Survival rates of not more than 50% are commonly reported even for tumors which appear to be confined to the uterus. Small areas of UPSC can be found in otherwise well-differentiated endometrial lesions and yet still determine the overall prognosis. In the present study we evaluated histologic criteria that might be helpful in diagnosing small-volume UPSC, including silver-stained nucleolar organizer regions (AgNOR) which have prognostic importance in a variety of tumors, and nuclear size which has been used for prognostication in endometrial cancer. We examined 25 UPSC specimens and compared them to grade III (GIII, n = 10) and grade I (GI, n = 10) typical endometrial adenocarcinoma using the following parameters: mean AgNOR count per cell was UPSC 6, GIII 6.0, and GI 4.3; mean AgNOR area was UPSC 1.28 microns2, GIII 1.35 microns2, and GI 0.86 microns2; total AgNOR area per cell was UPSC 7.5 microns2, GIII 8.13 microns2, GI 4.47 microns2; and nuclear size was UPSC 66.9 microns2, GIII 60.3 microns2, GI 34.8 microns2. All differences between UPSC or GIII tumors and GI lesions were statistically significant. Overexpression of p53, as determined histochemically, was seen in 64% of the UPSC specimens. UPSC is characterized by high AgNOR count and area per cell, large nuclear size, and a high rate of p53 overexpression. Evaluation of these parameters in biopsy material may aid in selecting high-risk patients for adjuvant therapy trials.
 ...
PMID:Histologic characterization of uterine papillary serous adenocarcinoma. 770 79

The polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method is a powerful tool for the screening of genetic alterations, including single-base substitutions. In the present study, the conventional SSCP technique was modified on the semiautomated electrophoresis system (PhastSystem) for the detection of mutations in the p53 tumor suppressor gene. The SSCP running conditions were optimized for three PCR-amplified DNA fragments, spanning exons 5 through 9 of the p53 gene, using the PCR-products derived from the CaSki and HaCaT cells as the normal and mutant controls, respectively. The optimized SSCP protocols were tested on nine human vulvar and vaginal carcinoma-derived cell lines. The optimizing experiments indicated that the running temperature and gel density can affect significantly the electrophoretic mobility and resolution of single-stranded DNA molecules. Because the gel temperature is the most important parameter affecting the conformation and thus electrophoretic mobility of single strands, one of the most important advantages of the SSCP technique on the PhastSystem is that the running temperature is controlled precisely. In addition to the fast electrophoretic separation, the PhastSystem also offers the use of a silver staining method allowing direct visualization of DNA with high detection sensitivity. Thus, the important advantage of this modified SSCP technique is the short time required for analysis, including electrophoresis and DNA detection. It is concluded that the SSCP method applied on the PhastSystem has the advantages of simplicity, efficiency, speed and reproducibility, and is suitable for clinical diagnostic purposes.
 ...
PMID:Rapid and effective detection of mutations in the p53 gene using nonradioactive single-strand conformation polymorphism (SSCP) technique applied on PhastSystem. 773 Apr 36

There is strong association of Barrett's oesophagus (BO) with adenocarcinoma. The sequence of events preceding malignancy appears to be reflux oesophagitis - ulceration - BO - dysplasia. One hundred and five biopsies of heterotopic columnar epithelium were stained for H&E, PAS/Alcian Blue and HID/Alcian Blue for the routine histology and neutral/acidic sialo- and sulphomucin staining. Other sections were silver impregnated by the Grimelius technique. Immunohistochemical techniques were applied for the assessment of the accumulation of p53 protein, "S" phase of the replication cell cycle using proliferating cell nuclear antigen (PCNA), marked for cell differentiation and proliferation using EGF and TGFa. 105 cases of heterotopic columnar epithelium consisted of 74 cases of BO, 25 junctional and 7 corpus mucosa. Dysplastic BO (n = 9) showed similar amount of sulphomucin and endocrine cell number when compared to non-dysplastic. PCNA study revealed a close similarity between dysplastic, indefinite for dysplasia and non-dysplastic, mucosal positive counts. Growth factors activity was significantly higher in dysplastic and indefinite than in non-dysplastic, but no such difference was found between dysplastic and indefinite for dysplasia BO. There was a significant concurrent p53 expression in dysplastic and indefinite for dysplasia BO. In conclusion, the practical utility of mucin stainings, endocrine cell count, assessment of cell proliferation and differentiation by PCNA, EGF and TGFa seems to be limited in differentiation of the dysplastic and indefinite for dysplasia BO. Altered expression of p53, particularly in combination with EGF and TGFa, may be useful in studying these lesions.
 ...
PMID:Barrett's oesophagus: mucin composition, neuroendocrine cells, p53 protein, cellular proliferation and differentiation. 784 25

A series of 200 breast carcinomas was investigated on frozen sections using PAb 1801 p53 monoclonal antibody and streptavidin biotin peroxidase complex. Densitometric analysis of the immunoprecipitates was assessed by processing digitized microscopic images. p53 was observed in the nucleus of 48% of the tumors. Some tumors (14 of 91) tested in parallel on paraffin sections were negative, although positive on frozen sections. Image analysis showed that the surfaces positive with anti-p53 and the staining intensity were decreased (P < .01) on paraffin sections. The p53 tumor expression was independent of patient age, tumor size, axillary lymph node status, HER-2/neu and cathepsin D expression, and nuclear morphometric parameters. However, p53 correlated with high histological grade (P < .01), lack of estrogen receptor (ER) (P = .0015) and progesterone (PR) (P = .0065) antigenic sites, pS2 detection (P = .03), high Ki-67 immunoreactivity (P = .018), large silver-stained nucleolar organizer region (AgNOR) nuclear surface ratio (P < .02), and degree of hyperploidy (P < .03), and was more often observed in the comedocarcinomas. The results suggest that p53 expression in breast carcinomas is not a totally independent prognostic indicator and that the clinical relevance and prognostic significance of p53 expression in breast carcinomas can be reliably assessed provided that the procedures are standardized, particularly with regard to the use of frozen sections and image analysis processing of the immunodetection.
 ...
PMID:p53 quantitative immunocytochemical analysis in breast carcinomas. 786 46

Loss or inactivation of p53 gene--a suppressor oncogene has been considered to be one of the important mechanisms in the development of human tumors. One of the evidences for mutation of allelic gene of p53 is the identification of p53 protein concentrated in the nuclei of related cells. By using ABC immunohistochemical method, we studied the expression of p53 in cryostatic sections of the tumor tissue and adjacent mucosa resected from 38 patients with gastric cancer. p53 was found to be positive in the nuclei with intensive staining in 24 out of 38 cases with carcinoma (63.2%). p53 positive cells were distributed diffusively in the cancer tissue. All the adjacent mucosa specimens except 10 were negatively stained with p53 monoclonal antibody. These 10 specimens including 3 with dysplasia and 4 with metaplasia were only weakly stained. p53 was also found to be positive in 18 out of 23 cancer patients with metastasis in perigastric lymph nodes (78.3%). We also studied in the same section the nucleolar organizer region-associated proteins (AgNORs) with using silver staining technique to find if there is any relationship between p53 gene mutation and the activity of rRNA transcription of tumor cells. The number of AgNORs dots per nucleus detected in gastric cancer sections with positive staining of p53 (9.9 + 2.14) was greater than those with p53 negative staining (7.2 + 1.68). There was a significant statistical difference between the two groups (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[The expression of mutant p53 gene in gastric carcinoma]. 786 23

Seventy eight cases of carcinoma and 14 cases of poly of large intestine were examined to observe the expression of p53, rasp21 and p185 oncoproteins with immunogold silver staining method. The positive expressions for p53, rasp21 and p185 were 53.9%, 46.2% and 51.3% respectively. But only poorly positive expression was found in large intestine polyps for p185 staining. The difference between the carcinomas and polyps for p185 staining was significant (P < 0.01). The normal mucoepithelium near the cancer region expressed positive staining for p53, rasp21 and p185 were 0%, 2.6% and 5.1% respectively. These results were also significantly different when compared to cancer tissue (P < 0.01). In addition, of these 78 cases, 33 cases (42.3%) gave coordinately positive expression for p53 and rasp21 oncoprotein; p53 positive expression was obviously stronger in poorly differentiated carcinoma and mucoadenocarcinoma than in highly and moderately differentiated adenocarcinoma (P < 0.01).
 ...
PMID:[Expression and significance of oncoprotein p53, rasp21 and p185 in carcinomas and polyps of the large intestine]. 791 70

We have developed a means of nonradioisotopic single strand conformation polymorphism (nonRI-SSCP) analysis and applied it to the detection of a point mutation in the human tumor suppressor gene, p53. The method does not require any particular facilities or apparatus, such as a laboratory for radioactive materials, a large gel unit for sequencing, or a semiautomated electrophoresis system. This technique comprises amplification of DNA fragments by the PCR technique with specific oligonucleotide primers, denaturation, and electrophoresis on neutral polyacrylamide gels in a conventional minislab apparatus. The SSCP patterns on electrophoresis were detected with a commercially available silver stain method. We also evaluated various electrophoretic conditions for nonRI-SSCP analysis, such as the gel concentration and buffer components. A tris/glycine buffer system gave better resolution of SSCP bands. The SSCP patterns of different sized DNAs could be analyzed in a gradient polyacrylamide gel. Thus, nonRI-SSCP analysis with a conventional minislab gel electrophoresis apparatus can be satisfactorily substituted for a commonly used RI-SSCP technique.
 ...
PMID:Optimization of nonradioisotopic single strand conformation polymorphism analysis with a conventional minislab gel electrophoresis apparatus. 823 76


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