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)

Allelic loss of chromosome 17p with a mutated p53 gene on the remaining allele has been observed in various kinds of human cancers. To examine the significance of allelic loss of chromosome 17p in human urothelial cancer with special attention to the clinicopathological features, 49 tumors with various stages and grades from 43 cases (35 bladder cancers and 8 renal pelvic or ureteral cancers) were examined for loss of heterozygosity using 5 polymorphic probes on chromosome 17p. Thirty-seven cases were informative, and allelic loss of chromosome 17p was observed in 15 (41%) of them. In bladder cancers, the loss of 17p was observed with significantly higher frequency (p < 0.01) in cases with invasive (> or = pT2) tumors (7/10, 70%) than in cases with superficial (pTa or pT1) tumors (4/21, 19%). In renal pelvic or ureteral cancers, none of 2 superficial tumors and all of 4 invasive tumors showed the allelic loss. As to tumor grade, the allelic loss was observed in 1/9 (11%) for grade 1 cases, 6/18 (33%) for grade 2 cases, and 8/10 (80%) grade 3 cases (grade 1 versus 3, p < 0.01; grade 2 versus 3, p < 0.05). On the other hand, examination of clinical features, such as primary tumor site, tumor multiplicity or previous history of urothelial cancer did not significantly influence the frequency of the allelic loss. Our results suggest that the allelic loss of chromosome 17p is strongly associated with invasive phenotype in urothelial cancer. The results further indicate that the 17p deletion may represent a new genetic marker of malignant potentials in urothelial cancers.
 ...
PMID:Allelic loss of chromosome 17p in urothelial cancer: strong association with invasive phenotype. 143 75

Structural alterations of the p53 gene were investigated to elucidate the molecular biological difference between superficial and invasive bladder cancer by polymerase chain reaction single-strand conformation polymorphism analysis. In 25 bladder cancers obtained from 23 patients, p53 gene mutations were investigated in exon regions 4 to 11. Twenty-four were transitional cell carcinomas, and the remaining one was a squamous cell carcinoma. Only one of 13 superficial bladder cancers, including pTis, pTa, and pT1, was found to have p53 gene mutation. However, of 12 invasive bladder cancers with pT2, pT3, and pT4, six primary carcinomas, including a squamous cell carcinoma and one metastatic carcinoma, were found to have p53 gene mutations. The number of cancers examined in Grades 1, 2, and 3 was three, seven, and 15, respectively. p53 gene mutation was not found in any of the ten cancers with Grades 1 and 2, while eight of 15 bladder cancers with Grade 3 were found to have p53 gene mutation. The results indicated that the incidence of p53 gene mutations appeared to be much higher in invasive-type and high-grade bladder cancers than in superficial and low-grade ones. Our results are compatible with the recently published results by Sidransky et al. [Science (Washington DC), 252: 706-709, 1991] showing that p53 gene mutations were frequently found in invasive bladder cancers by sequence analysis on polymerase chain reaction amplified products corresponding to exons 5 to 9. Our results are also compatible with previously reported results by Olumi et al. (Cancer Res., 50: 7081-7083, 1990) showing that the loss of chromosome 17p, revealed by analysis with restriction fragment length polymorphism, was frequent in high-grade bladder cancers. In this study, p53 gene mutations were often found in exon 4 as well as in other exons. Therefore, this region should also be examined for screening of mutations of this gene in bladder cancer. There appeared to be no consistent mutation sites in exons 4 to 11 of the p53 gene and no specific patterns of the mutation in bladder cancer.
 ...
PMID:Frequent association of p53 gene mutation in invasive bladder cancer. 154 Sep 47

Overexpression of p53 and erbB-2 was studied by immunohistochemistry in formalin-fixed tissue samples of 179 patients with transitional cell carcinoma of the urinary bladder. p53 immunostaining was strongly correlated with tumour stage (P < 0.0001). This was driven by a marked difference in p53 expression between pTa (37% positive) and pT1 (71%) tumours, while there was no difference between pT1 and pT2-4 tumours. Similarly, a strong overall association between p53 expression and grade (P < 0.0001) was driven by a marked difference between grade 1 (28%) and grade 2 tumours (71%), and there was no significant difference between grade 2 and grade 3 tumours. Surprisingly, the frequency of erbB-2 overexpression was higher in pT1 tumours (74%) than in either pTa (49%; P = 0.0265) or pT2-T4 (56%; P = 0.0645) tumours. Both p53 and erbB-2 expression was also associated with metastasis. Metastases were found in 77% of patients with p53 positive primary tumours, but in only 50% of the patients with p53 negative primary tumours (P = 0.022). Metastases were found in 66% of patients with erbB-2 positive primaries, but in only 37% of the erbB-2 negative primaries (P = 0.020). Of 32 patients with positivity for both p53 and erbB-2, 84% developed metastases, as compared to 49% of patients with positivity for either one or neither positive (P = 0.002). We conclude that both p53 and erbB-2 overexpression are associated with early invasion in bladder cancer. Furthermore, p53 and erbB-2 may be important predictors for metastasis.
 ...
PMID:p53 and erbB-2 protein overexpression are associated with early invasion and metastasis in bladder cancer. 750 41

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

Mutations in the tumor suppressor gene p53 have been detected in many tumors. p53 gene mutations are also known to be involved in the progression of human bladder cancers. We investigated structural alterations in the entire coding region of the p53 gene in primary human bladder cancers, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. Of 25 samples obtained from patients, 6 (24%) were found to have p53 alterations. DNA sequencing of the PCR products revealed 6 point mutations resulting in single amino-acid substitutions in the regions of exons 5, 6, 7, 8, and 10 of this gene, respectively. Five of 6 cases with p53 mutations were invasive, with metastasis or high-grade tumors. Interestingly, the one remaining case was a recurrent, low-grade, and superficial (pTa) tumor. In this early stage tumor, allelic loss of the p53 gene was also found, using a polymerase chain reaction-based restriction fragment length polymorphism assay. Our findings are in agreement with previous observations that p53 mutations occurred in a high percentage of high grade or invasive bladder cancers. Since mutation and allelic loss of the p53 gene were also detected in a low-grade and low-stage tumor in the present study, it is suggested that the p53 gene is involved in early stages of some bladder cancers as well as in their late stages.
 ...
PMID:Analyses of p53 gene mutations in primary human bladder cancer. 812 44

To understand better the role of physical p53 deletion in bladder cancer, 106 formalin-fixed and 45 unfixed bladder tumors were examined using fluorescence in situ hybridization. Probes for centromere 17 and the p53 locus were hybridized simultaneously to interphase tumor cells to analyze p53 and chromosome 17 copy number on a cell by cell basis. 17p deletion was found in four of 43 pTa tumors, 18 of 43 pT1 tumors and 29 of 58 pT2-4 tumors (P = 0.0001). 17p deletion was also highly correlated with grade (P = 0.0001) and with p53 immunostaining (P = 0.0005). Chromosome 17 polysomy was associated with stage, grade, 17p deletions, and p53 immunostaining (P = 0.0001). The strong difference in centromere 17 copy number and 17p deletions between pTa and pT1 tumors supports a relevant biological distinction between pTa and pT1 tumors.
 ...
PMID:Physical deletion of the p53 gene in bladder cancer. Detection by fluorescence in situ hybridization. 816 Jul 75

This study is aimed at determining the usefulness of nuclear DNA content and S-phase fraction (SPF) to predict tumor recurrence in papillary superficial bladder cancer. Tumor DNA content and SPF were measured by flow cytometry on formalin-fixed, paraffin-embedded tissue from 199 newly diagnosed pTa/pT1 transitional cell carcinomas of patients enrolled into a multicenter prospective study from 1990 to 1992. The follow-up extended up to March 1994, and, at last follow-up, 122 (61.3%) patients have experienced at least one recurrence. After exclusion of 34 cases, whose coefficient of variation exceeded 8%, 131 (79.4%) tumors were diploid, and 34 (20.6%) were aneuploid. There was no association between tumor DNA content and time to first recurrence. Diploid tumors with low SPF (< 11%) tended to have a longer recurrence-free survival (RFS) than those with high SPF, but this difference did not reach statistical significance (P = .2833). SPF in aneuploid tumors did not add any new information. Aneuploidy was associated with higher stage (P < .001), poorer grade (P < .002), multifocality (P = .028), Her-2/neu (P = .021), and p53 (P = .033) expression. High SPF correlated with higher stage (P = .066) and higher grade (P = .025). This study shows that DNA-ploidy and SPF measured on a single superficial bladder cancer specimen are not predictive of tumor recurrence. The frequent multifocality of the disease may explain, in part, these findings.
 ...
PMID:Prognostic significance of nuclear DNA content and S-phase fraction by flow cytometry in primary papillary superficial bladder cancer. 881 87

We present a retrospective study using four different immunohistochemical markers (PCNA, Ki-67, 486p and p53) on paraffin sections from 104 selected cases with primary superficial transitional cell carcinomas of the bladder (59 cases pTa, 45 cases pT1, 40 cases G1, 64 cases G2). 53 of the 104 patients experienced recurrence of their bladder lesion, while 51 remained free of tumor. The distribution of staging, grading and multifocality was comparable in both groups of patients. Overall, the tumors that recurred had a significantly higher proportion of labeled cells for PCNA (p < or = 0.0001), Ki-67 (p < or = 0.006) and 486p (p < or = 0.0001). The latter antigen proved to be the most reliable marker. A less significant difference in staining pattern was found for p53 (p < or = 0.01). Evaluating the predictive value of the various antibodies separately for the groups with G1 vs. G2 carcinomas and pTa vs. pT1 tumors revealed a lower significance for all antibodies. The technique of immunostaining on paraffin sections facilitates further retrospective studies on archival material. These markers may provide additional information about the probability of recurrence of superficial bladder tumors. But at the moment they should only be utilized in selected cases.
 ...
PMID:Expression of immunohistochemical markers (PCNA, Ki-67, 486p and p53) on paraffin sections and their relation to the recurrence rate of superficial bladder tumors. 939 55

At present, the most efficacious and used immunostimulant agent in the superficial bladder cancer immunotherapy field, is the BCG, even if its mechanism of action is still partly unknown. The therapeutic effects of BCG don't seem to depend exclusively on local immune response, so that according to this assertion, this immunohistochemical study had been conducted on 14 patients affected by superficial bladder cancer (pTa-pT1) which aimed to value both the apoptosis and proliferation indexes and the expression of the genetic product p53 and EGFR before and after the exposition of the vesical mucosa to the BCG. The BCG treatment can reduce the proliferation index of the normal urothelial cells in a statistically significant way whereas it would exclude a cytostatic effect mediate by negative modulation of EGFR from the cytokinins induced by BCG itself. The index of apoptosis of the urothelium does not increase after BCG and decreased expression of p53 associated after the treatment, although statistically not significant, it would seem to bear, the prophylactic efficacy of BCG according to the follow up of the patients included in the study.
 ...
PMID:[Cellular proliferation, expression of p53, EGFR and apoptosis index of healthy mucosa of the bladder with TCC; pre- and post-intravesical BCG immunohistochemical study]. 941 99

Mutations of p53 gene have been found in a variety of human malignancies; however, the impact of immunohistological detection of p53 expression in the development and progression of TCC of the bladder is still uncertain. In the present study, we investigated the p53 oncoprotein expression and compared the findings to DNA ploidy and pathohistological stage and grade. The study included 147 patients with transitional cell carcinoma of the bladder investigated between February 1981 and September 1994. The average age of the 55 women and 92 men was 67 years (range: 20-71 years). A total of 76 patients (52%) had stage pTa to pT1, 35 (24%) stage pT2, 25 (17%) stage pT3, and 11 (7%) stage pT4 disease. Frozen sections of tumor biopsies obtained by transurethral resection were immunohistochemically stained using the monoclonal antibody clone D0-7 (DAKO), which recognized two different epitopes for mutant and wild-type p53 protein. Tumors expressing p53 in more than 10% of the tumor nuclei were regarded as positive. The DNA ploidy was determined by image analysis. Immunohistochemical detection of p53 expression was found in 84 (57%) of the 147 tumors examined. Positive p53 staining was seen in grade I tumors in 10 to 25%, in grade II tumors 25 to 75%, and in grade III up to 58% of the tumor nuclei. There was a positive correlation between p53 expression and pathological stage (28% in pTa, 73% in pT1-2, and 68% in pT3-4 tumors). There was no appreciable relationship between DNA Ploidy and p53. Although carcinomas with p53 expression had a slight tendency to be more prevalent among higher disease stages and poorly differentiated transitional cell carcinoma, immunohistochemical detection of p53 is not a valuable tool for predicting the outcome of patients with TCC or for identifying subgroups of patients that may be at a higher risk for tumor progression.
 ...
PMID:Immunohistochemical detection of p53 protein in transitional cell carcinoma of the bladder in correlation to DNA ploidy and pathohistological stage and grade. 946 48


1 2 3 4 5 Next >>