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)

Immunohistochemical studies were performed to clarify the significance of the expression or overexpression of epidermal growth factor (EGF), EGF-receptor (EGFR), p53, v-erb B, ras p21 in 23 cases each of tubular adenoma and adenocarcinoma. The expression of EGF, EGFR, p53, v-erb B, and ras p21 in paraffin-embedded tissues, from 46 patients with colorectal tumors (adenoma: 23 cases; 14 mild dysplasia, six moderate dysplasia, three severe dysplasia, adenocarcinoma: 23 cases; 17 well differentiated, two moderately differentiated, three poorly differentiated, one mucinous carcinoma was analyzed immunohistochemically using anti-EGF, EGFR, p53, v-erb B and ras p21 antibodies. The EGF and ras p21 tended to express more strongly in carcinoma cases than in the adenoma cases, and in severe and moderate dysplasia than in mild dysplasia (EGF: stained positive in five adenomas [21.74%] and 17 adenocarcinomas [73.91%]; ras p21: stained positive in six adenomas [26.09%] and 14 adenocarcinomas [60.87%]. The EGFR stained positive in two adenomas (8.70%) and two adenocarcinomas (8.70%). The p53 and v-erb B showed positive staining only in the carcinoma cases (p53: stained positive in four cases [17.39%]; v-erb B: stained positive in eight cases [34.78%]). This study suggests that these factors seem to have some role in the progression of colon neoplasms. It suggests that genetic alteration is not always equal to the overexpression of protein products, but that it reflects them well, and that the staining makes some contribution to differential diagnosis in colorectal neoplasms.
 ...
PMID:Expression of EGF, EGF-receptor, p53, v-erb B and ras p21 in colorectal neoplasms by immunostaining paraffin-embedded tissues. 791 78

The aim of the current study was to identify genetic abnormalities in human colorectal adenoma and carcinoma derived cell lines, and to determine whether the genetic changes which occur in vitro are relevant to the in vivo situation. Loss of 1p(33-35) region was shown to be the most common chromosome 1 abnormality and loss of heterozygosity (LOH) of the DCC gene and/or adjacent sequences was detected in all adenoma derived cells as well as the carcinoma cell lines. The level of p53 protein was also investigated as increased cellular p53 protein had previously been associated with mutation of the p53 gene. A further aim was to investigate genetic changes in our in vitro model of tumour progression, where the adenoma derived PC/AA cell line has previously been converted in vitro to two distinct tumorigenic phenotypes, producing either an adenocarcinoma or a mucinous carcinoma in athymic nude mice. Progression to the adenocarcinoma phenotype was shown to involve a specific chromosome 1 rearrangement, loss of both normal copies of chromosome 18 (although DCC gene sequences were retained), loss of the remaining wild type allele of k-ras resulting in homozygosity for the k-ras codon 12 mutation and increased cellular p53 protein as detected by SDS-PAGE Western blotting. The increase in p53 protein was shown not to be due to the acquisition of a mutation in the p53 gene. Interestingly, progression of the adenoma derived PC/AA cell line to the mucinous malignant phenotype did not involve any of these molecular rearrangements, suggesting that different genetically distinct pathways are involved in colorectal carcinogenesis. These studies show that the genetic changes in our in vitro model of human colorectal tumour progression are similar to those observed in in vivo studies.
 ...
PMID:Molecular events including p53 and k-ras alterations in the in vitro progression of a human colorectal adenoma cell line to an adenocarcinoma. 841 7

A series of 107 lymph node-negative (LNN) breast cancers was stained immunohistochemically with a combination of p53 and c-erb B-2. The immunohistochemical results were semiquantitated using a previously described system by Allred et al. p53 immunopositive cases were further screened for DNA mutations by the polymerase chain reaction-single-strand conformation polymorphism method (PCR-SSCP). Three representative cases showing mobility shifts were directly sequenced. One hundred of 103 invasive carcinomas were of no special type (infiltrating ductal carcinomas not otherwise specified). The three special type carcinomas included a tubular carcinoma, a classic infiltrating lobular carcinoma, and a mucinous carcinoma. Twenty-six patients (25.2%) had grade I carcinomas, and 77 patients (75%) had grade 2 or 3 carcinomas. There were four cases composed predominantly of ductal carcinoma in situ (DCIS) with foci of microinvasion. Twenty-seven of 107 patients (25%) died of disease. All those who died had grade 2 or 3 tumors. Univariate analysis showed that p53 and c-erb B-2 positivity (score > 6) were associated with a decreased overall survival (OS) (P = .0012 and P = .010, respectively), and a decreased disease-free survival (DFS) (P = .0009 and P = .027, respectively). The multivariate model selected these two variables as the best predictors of both OS and DFS (all P = or < .01). These results suggest that semiquantitative immunohistochemical analysis of p53 and c-erb B-2 provides prognostic information in LNN disease.
 ...
PMID:The predictive power of semiquantitative immunohistochemical assessment of p53 and c-erb B-2 in lymph node-negative breast cancer. 881 92

The clinical, pathological and biologic features of 79 mucinous colorectal carcinomas were compared with those of 602 non-mucinous adenocarcinomas. The two groups did not show appreciable differences in patients' age, stage distribution, extent of lymph node involvement, grade of differentiation, pattern of growth and venous invasion. Mucinous carcinomas occurred more frequently among female patients (P < 0.05) and in the proximal colon (P < 0.01). Moreover, mucinous carcinomas more often demonstrated origin within villous adenomas (P < 0.0001) and lacked pronounced peritumoural lymphocytic infiltration (P < 0.001). A strong association was found between tumour type and flow cytometric nuclear DNA content. A high proportion of mucinous carcinomas showed DNA index (DI) values < or = 1.20 (26/38, 68.4%); conversely only 103 of 322 (32%) non-mucinous carcinomas had a DI < or = 1.20 (P < 0.0001). In addition mucinous carcinomas were characterized by infrequent p53 overexpression (4/21, 19% versus 120/183, 65.6%; P < 0.001) and higher levels of proliferative activity (P < 0.0001) compared to non-mucinous adenocarcinomas. Our data support the hypothesis that mucinous carcinoma represents a distinct clinicopathologic and genetic entity.
 ...
PMID:[Clinico-pathological features and biological characterization of mucoid colorectal carcinoma]. 892 22

The origin of malignant ovarian epithelial tumors is uncertain and has been the subject of considerably controversy. Some favor the theory of origin in precursor lesions such as benign cystadenomas or tumors of low malignant potential (LMP; borderline tumors), whereas others favor the concept of an independent origin of carcinomas from the ovarian surface epithelium or inclusion cysts. Recently, the demonstration of identical molecular alterations in morphologically benign and malignant areas within the same ovarian tumor have suggested the possibility that the malignant epithelium had undergone differentiation to a benign appearance. Because both areas were present in the same tumor, however, the possibility of progression of the morphologically benign component could not be excluded. We present a case of simultaneous mucinous carcinoma and contralateral tumor of LMP which exhibited identical, unique mutations of the p53 gene, suggesting a clonal origin. Because these were separate and distinct tumors, we believe this case provides strong support for the differentiation hypothesis. We also provide evidence for markedly different levels of p53 expression in areas with identical p53 mutations.
 ...
PMID:Identical, unique p53 mutations in a primary ovarian mucinous adenocarcinoma and a synchronous contralateral ovarian mucinous tumor of low malignant potential suggest a common clonal origin. 915 13

The expressions of p53 and proliferating cell nuclear antigen (PCNA) were studied immunohistochemically from paraffin sections of 7 cases (9 lesions) of radiation-induced colon cancer and 42 cases of spontaneous colon cancer. Age distribution of radiation-induced and spontaneous colon cancer were 68.1 years (range, 56 to 77 years) and 67.4 years (range, 31 to 85 years), respectively. Among the radiation-induced colon cancers, there were 3 lesions of mucinous carcinoma (33%), a much higher than found for spontaneous mucinous cancer. Immunohistochemically, p53 protein expression was detected in 7/9 (78%) of radiation-induced cancers and in 23/42 (55%) of spontaneous colon cancers. chi 2 analysis found no significant differences between radiation-induced and spontaneous colon cancers in age distribution or p53-positive staining for frequency, histopathology, or Dukes' classification. In radiation colitis around the cancers including aberrant crypts, spotted p53 staining and abnormal and scattered PCNA-positive staining were observed. In histologically normal cells, p53 staining was almost absent and PCNA-positive staining was regularly observed in the lower half of the crypt. In radiation colitis including aberrant glands, cellular proliferation increased and spotted p53 expression was observed. This study suggests that radiation colitis and aberrant glands might possess malignant potential and deeply associate with carcinogenesis of radiation-induced colon cancer.
 ...
PMID:Immunohistochemical study of p53 overexpression in radiation-induced colon cancers. 961 28

Ovarian tumors of low malignant potential ("borderline tumors") have been proposed variably to represent a distinctive type of malignancy, precursors of frank ovarian malignancy, or a nonmalignant process. We analyzed 81 malignant and 39 borderline ovarian tumors for p53 immunoreactivity and alterations in codon 12 of Ki-RAS in order to correlate these alterations with tumor and cell type. Diffuse p53 immunoreactivity was significantly more prevalent among malignant (36 of 81, 44%) than among borderline (3 of 39, 8%) tumors and was particularly prevalent among serous invasive carcinomas (16 of 26, 62%). Conversely, mutations in codon 12 of Ki-RAS were significantly more prevalent in borderline (16 of 39, 41%) than in malignant (9 of 81, 11%) ovarian tumors and were most prevalent among mucinous tumors. This preliminary molecular analysis suggests that serous borderline tumors have some molecular features usually associated with malignancy but are unlikely to represent a precursor of invasive serous carcinoma. In contrast, mucinous borderline tumors may represent a precursor or variant of mucinous carcinoma of the ovary.
 ...
PMID:Comparison of mutations of Ki-RAS and p53 immunoreactivity in borderline and malignant epithelial ovarian tumors. 1007 24

A 17-year-old Turkish boy with Bloom syndrome (BS) developed mucinous carcinoma of the transverse colon. He was followed from 2 to 17 years of age. Increased sister chromatid exchanges (SCE) were observed, and he was diagnosed with BS at the age of 7. Sun-sensitive skin lesions were examined by skin biopsy, and histopathological studies of these lesions were done. During the follow-up period, an intraabdominal mass at the transverse colon was found, and mucinous carcinoma of colon was diagnosed at the age of 16. We examined TP53 protein expression from paraffin-embedded colon tissue of the patient with an immunohistochemical method. Polymerase chain reaction products of exons 4-9 of the TP53 gene were examined by SSCP. No evidence of overexpression of TP53 protein or mutations of the TP53 gene was observed. The patient in this report is the first case with a mucinous carcinoma of colon diagnosed at an early age in the Bloom Syndrome Registry. Based on our results, carcinoma of the colon in BS patient may occur earlier than 35 years of age and the TP53 gene may not be directly related to carcinoma in Bloom syndrome.
 ...
PMID:Mucinous carcinoma of the colon in a 16-year-old Turkish boy with Bloom syndrome: cytogenetic, histopathologic, TP53 gene and protein expression studies. 1032 90

We investigated the clinicopathological and genetic characteristics including patients' gender, age, tumour location, growth pattern, Dukes' stage, DNA ploidy, S-phase fraction, PCNA, apoptosis, c-erbB-2, bcl-2, K-ras, p53, DCC and heat shock protein in 32 mucinous carcinomas versus 261 non-mucinous carcinomas in the colorectum. Sixty percent of mucinous carcinomas were located in the right colon, 13% in the left colon and 27% in the rectum (p=0.01). More mucinous carcinomas grew in expanding pattern than non-mucinous carcinomas (66% vs 39%, p=0.005). Compared with non-mucinous carcinoma, mucinous carcinoma had more K-ras mutations (50% vs 25%, p=0.02), but less p53 expression (72% vs 49%, p=0.02) and less apoptotic activity (19% vs 51%, p=0.01). We further confirm that the mucinous carcinoma in the colorectum represents a distinct clinicopathologic and genetic features as compared to non-mucinous tumour, and may have a different biological behaviour.
 ...
PMID:Clinicopathological and genetic characteristics of mucinous carcinomas in the colorectum. 1033 57

Although mucinous carcinoma (MC) of the breast is considered to originate from ductal carcinoma, it is not known whether mucinous growth begins in the intraductal carcinoma or later in the invasive carcinoma. In this study, 33 MC (16 pure without any ductal components, 10 mixed Type I with an intraductal component, seven mixed Type II with a common invasive ductal carcinoma (IDC) component)) were examined to clarify the time when mucinous growth begins. Histochemical and immunohistochemical examinations of mucin revealed that mucinous growth can begin in the intraductal carcinoma and in the common IDC. Histological transition and clonality analysis using microsatellite markers supported that some MC originate from common IDC. The pure type of MC probably originates from the intraductal carcinoma, showing a micropapillary feature. Neuroendocrine differentiation, known to be associated with MC, seemed to create the main progress in the typical MC. Moreover, we analyzed the factors of a worse prognosis of mixed MC Type II, which was strongly suggested by the lymph node status. However, no explainable differences on the cell proliferating ability, or c-erbB-2 and p53 protein overexpression were found.
 ...
PMID:Mucinous carcinoma of the breast: a multifaceted study with special reference to histogenesis and neuroendocrine differentiation. 1059 40


1 2 3 4 5 6 Next >>