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)

Colorectal cancer is a significant cause of morbidity and mortality in Western populations. This cancer develops as a result of the pathologic transformation of normal colonic epithelium to an adenomatous polyp and ultimately an invasive cancer. The multistep progression requires years and possibly decades and is accompanied by a number of recently characterized genetic alterations. Mutations in two classes of genes, tumor-suppressor genes and proto-oncogenes, are thought to impart a proliferative advantage to cells and contribute to development of the malignant phenotype. Inactivating mutations of both copies (alleles) of the adenomatous polyposis coli (APC) gene--a tumor-suppressor gene on chromosome 5q--mark one of the earliest events in colorectal carcinogenesis. Germline mutation of the APC gene and subsequent somatic mutation of the second APC allele cause the inherited familial adenomatous polyposis syndrome. This syndrome is characterized by the presence of hundreds to thousands of colonic adenomatous polyps. If these polyps are left untreated, colorectal cancer develops. Mutation leading to dysregulation of the K-ras protooncogene is also thought to be an early event in colon cancer formation. Conversely, loss of heterozygosity on the long arm of chromosome 18 (18q) occurs later in the sequence of development from adenoma to carcinoma, and this mutation may predict poor prognosis. Loss of the 18q region is thought to contribute to inactivation of the DCC tumor-suppressor gene. More recent evidence suggests that other tumor-suppressor genes--DPC4 and MADR2 of the transforming growth factor beta (TGF-beta) pathway--also may be inactivated by allelic loss on chromosome 18q. In addition, mutation of the tumor-suppressor gene p53 on chromosome 17p appears to be a late phenomenon in colorectal carcinogenesis. This mutation may allow the growing tumor with multiple genetic alterations to evade cell cycle arrest and apoptosis. Neoplastic progression is probably accompanied by additional, undiscovered genetic events, which are indicated by allelic loss on chromosomes 1q, 4p, 6p, 8p, 9q, and 22q in 25% to 50% of colorectal cancers. Recently, a third class of genes, DNA repair genes, has been implicated in tumorigenesis of colorectal cancer. Study findings suggest that DNA mismatch repair deficiency, due to germline mutation of the hMSH2, hMLH1, hPMS1, or hPMS2 genes, contributes to development of hereditary nonpolyposis colorectal cancer. The majority of tumors in patients with this disease and 10% to 15% of sporadic colon cancers display microsatellite instability, also know as the replication error positive (RER+) phenotype. This molecular marker of DNA mismatch repair deficiency may predict improved patient survival. Mismatch repair deficiency is thought to lead to mutation and inactivation of the genes for type II TGF-beta receptor and insulin-like growth-factor II receptor. Individuals from families at high risk for colorectal cancer (hereditary nonpolyposis colorectal cancer or familial adenomatous polyposis) should be offered genetic counseling, predictive molecular testing, and when indicated, endoscopic surveillance at appropriate intervals. Recent studies have examined colorectal carcinogenesis in the light of other genetic processes. Telomerase activity is present in almost all cancers, including colorectal cancer, but rarely in benign lesions such as adenomatous polyps or normal tissues. Furthermore, genetic alterations that allow transformed colorectal epithelial cells to escape cell cycle arrest or apoptosis also have been recognized. In addition, hypomethylation or hypermethylation of DNA sequences may alter gene expression without nucleic acid mutation.
 ...
PMID:Molecular biology of colorectal cancer. 943 4

The expression of several apoptosis-regulating genes was evaluated in 9 human breast cancer cell lines, 2 immortalized human mammary epithelial lines, 1 normal breast tissue biopsy, and 3 primary breast tumors, using a multiple antigen detection (MAD) immunoblotting method. The anti-apoptotic proteins Bcl-2, Bcl-X(L), Mcl-1, and BAG-1 were present at immunodetectable levels in 7, 10, 10, and 9 of the 11 lines. Comparing these 11 cell lines among themselves revealed that steady-state levels of Bcl-2, Bcl-X(L), Mcl-1, and BAG-1 were present at relatively higher levels in 4, 6, 5, and 5 of the lines, respectively. In contrast, the pro-apoptotic proteins Bax and Bak were detected in all 11 cell lines, and were present at relatively higher levels in 10 and 5 of the 11 lines, respectively. The Interleukin-1beta converting enzyme (ICE) homolog CPP32 (Caspase-3) was expressed in 10/11 breast cell lines. High levels of p53 protein, indicative of mutant p53, were found in 8 of the 11 lines and correlated inversely with Bax expression (p = 0.01). Bcl-2 and BAG-1 protein levels were positively correlated (p = 0.03). Immunoblot analysis of primary adenocarcinomas revealed expression of the anti-apoptotic proteins Bcl-2, Bcl-X(L), Mcl-1, and BAG-1, as well as the pro-apoptotic proteins Bax, Bak, and CPP32, in at least 2 of the 3 tumors examined. Immunohistochemical analysis was also performed for all of these proteins using 20 paraffin-embedded breast cancer biopsy specimens that all contained residual normal mammary epithelium in combination with both invasive cancer and carcinoma in situ. All of these apoptosis-regulating proteins were detected in primary breast cancers, though the percentage of immunopositive tumor cells varied widely in some cases. Comparisons of the intensity of immunostaining in normal mammary epithelium and invasive carcinoma suggested that Bcl-2 immunointensity tends to be lower in cancers than normal breast epithelium (p = 0.03), whereas CPP32 immunointensity was generally higher in invasive cancers (p < 0.0001). Taken together, the results demonstrate expression of multiple apoptosis-modulating proteins in breast cancer cell lines and primary tumors, suggesting complexity in the regulation of apoptosis in these neoplasms of mammary epithelial origin.
 ...
PMID:Expression of multiple apoptosis-regulatory genes in human breast cancer cell lines and primary tumors. 949 1

Matrix metalloproteinases are believed to play an important role in tumor progression, invasion and metastasis. In order to investigate if the expression of stromelysin-3 (ST3) mRNA could add prognostic information concerning invasive laryngeal cancer and/or be indicative of a high risk for tumor progression in laryngeal dysplasias ST3 expression was analyzed by in situ hybridisation of formalin fixed paraffin embedded laryngeal specimens. Furthermore, all specimens underwent image cytometry (ICM) DNA analysis, and, p53 immunostaining. Invasive epithelial cancer, both localized (T1, T2) cancers, cured, as well as not cured, by radiotherapy, and cases with regional lymph node metastases were studied. Furthermore, high grade and low grade dysplasias, selected for rapid, slow and non-progression, as well as non-neoplastic inflammatory lesions were investigated. Expression of the ST3 gene was found in 9 out of 14 (64%) invasive cancer lesions, and in 3 out of 10 (30%) dysplasias, thus indicating that ST3 expression correlates to tumor progression. The ST3 positive laryngeal cancer lesions displayed a higher degree of DNA aberration than the ST3 negative lesions thus suggesting that ST3 positivity could indicate highly malignant tumors. Of the three ST3 positive dysplasias, the first progressed rapidly to cancer in situ with suspected microinvasion. The second ST3 positive dysplasia progressed to invasive cancer within five months. The third ST3 positive dysplasia had been radically excised and hereby cured. All but one of the dysplastic lesions showed p53 immunoreactivity, and all dysplasias exhibited aneuploid cells. ST3 expression appears to be a late event in the multistage process of carcinogenesis and could prove useful as an indicator of dysplasias with imminent risk for progression to invasive cancer.
 ...
PMID:Stromelysin-3 mRNA expression in dysplasias and invasive epithelial cancer of the larynx. 949 47

Apoptosis is considered to play a critical role in tumorigenesis. It has been shown that apoptosis is controlled by both pro-oncogenes bcl-2, c-myc and tumor-suppressor genes p53. We determined the apoptotic index (AI) on light microscopy and detected immunohistochemically the expression of bcl-2 and p53 in patients with breast cancer. The correlations between AI and clinicopathological factors, bcl-2 and p53 were also analyzed. Our results showed that bcl-2 expression was down-regulated in the process from normal breast epithelial cells to intraductal carcinoma and from intraductal carcinoma to invasive carcinoma. We failed to detect p53 protein in normal breast epithelial cells, and p53 positivity was 24% and 30% in intraductal and invasive cancer tissues, respectively. Moreover, AI was significantly associated with histological grade, mitotic index, and bcl-2 and p53 expression. In univariate analyses, lower AI and bcl-2 expression was significantly predictive of a better prognosis for both disease-free survival and overall survival. These results suggest that apoptosis and apoptosis-related gene (bcl-2, p53) are related to progression and prognosis in breast cancer.
 ...
PMID:[Correlation between apoptotic index, bcl-2 protein expression and progression and prognosis in breast carcinoma]. 958 45

In a prospective pilot study, we performed breast fine needle aspirations (FNAs) on 224 high-risk and 30 low-risk women and analyzed these aspirates for cytologic changes and biomarker abnormalities of aneuploidy and overexpressed estrogen receptor (ER), epidermal growth factor receptor (EGFR), p53 and HER-2/neu. High-risk women had a first-degree relative with breast cancer (74%), prior biopsy indicating premalignant breast disease (25%), a history of breast cancer (13%), or some multiple of these risk factors (12%). Median ages of the high- and low-risk groups were 44 and 42, respectively. Seventy percent of high-risk and 17% of low-risk women had cytologic evidence of hyperplasia with or without atypia (P < .0001). Aneuploidy and overexpression of EGFR and p53 occurred in 27, 37, and 29% of high-risk subjects but only 0, 3, and 3% of low-risk subjects (P < .0023). Overexpression of ER and HER-2/neu occurred in 7 and 20% of high-risk women but in none of the low-risk subjects. Biomarker abnormalities were more frequent with increasing cytologic abnormality. Restricting the analysis to those 3 biomarkers most frequently overexpressed in the high-risk group (ploidy, EGFR, p53), 13% of high-risk women with normal cytology, 19% of high-risk women with epithelial hyperplasia, and 49% of high-risk women with hyperplasia with atypia had abnormalities of 2 or more of these 3 biomarkers (P = .00004). At a median follow-up of 32 months, four women have been diagnosed with invasive cancer and two with ductal carcinoma in situ (DCIS). Later detection of these neoplastic conditions was associated (P < or = .016) by univariate analysis with prior FNA evidence of hyperplasia with atypia; overexpression of p53 and EGFR; the modified Gail risk of breast cancer development at 10 years; and multiple biomarker abnormalities. By multivariate analysis, later detection of cancer was primarily predicted by the number of biomarker abnormalities in the 3-test battery (P = .0005) and secondarily by the Gail risk at 10 years (P = .0049). In turn, hyperplasia with atypia was associated with multiple biomarker abnormalities, particularly p53 and EGFR overexpression. Thus, hyperplasia with atypia and cytologic markers in breast FNAs have promise as risk predictors and as surrogate endpoint biomarkers for breast cancer chemoprevention trials.
 ...
PMID:Breast cytology and biomarkers obtained by random fine needle aspiration: use in risk assessment and early chemoprevention trials. 958 54

Pathologic and epidemiologic investigations carried out over the past several years have provided evidence that carcinogenesis in the uterine cervix is a multi-step process involving discreet preinvasive stages. Molecular epidemiologic data also indicate that human papillomavirus (HPV) infection is a critical factor in the tumor progression process. In vitro studies have shown that for the initiation and maintenance of the malignant phenotype, the expression of the HPV-transforming protein E6 is required. The E6 protein produced by the high-risk HPV types 16 and 18 can bind to and inactivate the tumor suppressor protein p53 leading to deregulated proliferation and defective apoptosis, thus facilitating tumor progression. Therefore, determination of the HPV genotype alone may not be sufficient in assessing tumor progression in the uterine cervix. In the present study, a total of 623 cervical tissue samples at various phases of tumor progression were assessed for HPV infection by nonisotopic in situ hybridization (NISH) and for HPV 16/18 E6 protein expression by immunocytochemistry. There was significant correlation between the extent of histological abnormality and HPV infection. Significant correlation (r = 0.707, p = 0.000) was observed between the presence of HPV 16 and high-grade squamous intraepithelial lesions (SILs) and invasive cancer. The odds ratio of a cervical tissue infected with HPV 16 falling into these two categories was 44.57 (95% CI: 27.10, 73.30). The E6 protein also was mostly detected in high-grade SILs and cervical cancer tissue expressing either HPV 16 or 18. It was less frequent in low-grade SILs infected with HPV 16/18 and was absent in benign cervical tissue infected with HPV 16. The odds ratio of an HPV-16/18-infected cervical tissue positive for E6 being a high-grade SIL or invasive cancer was 16.20 (95% CI: 6.06, 43.33). These results thus show the clinical utility of HPV characterization along with the analysis of the transforming protein E6 in the assessment of tumor progression in the uterine cervix.
 ...
PMID:High-risk human papillomavirus infection and E6 protein expression in lesions of the uterine cervix. 973 39

Intravesical doxorubicin treatment delivers high drug concentrations to the bladder wall, yet the treatment produces only a variable and incomplete response in superficial bladder cancer and insignificant activity in muscle-invading disease. This study evaluated the pharmacological basis for the clinical observations and potential prognostic indicators of tumor sensitivity to doxorubicin. The pharmacodynamics of doxorubicin were studied using histocultures of surgical specimens of seven superficial (Ta and T1) and nine invasive (T2-T4) tumors. After a 2-h exposure, drug treatment caused a concentration-dependent inhibition of proliferation, as measured by bromodeoxyuridine incorporation into DNA. Extensive cell death was observed at high concentrations (>10 micrometer) in sensitive tumors. The IC50 values ranged from 0.14 to 5.2 micrometer for superficial tumors and from 1.4 to >100 micrometer for invasive tumors. A comparison of the IC50 and IC90 values with the drug concentrations previously determined in human bladder walls showed that IC50 was achieved in all Ta tumors, 67-100% of T1 tumors, and one of the nine invasive tumors, whereas IC90 was achieved in all Ta tumors but none of the other tumors. To determine the biological basis of variable doxorubicin sensitivity among different tumors, we examined the relationship of chemosensitivity with tumor pathology and with expression of multidrug resistance p-glycoprotein (Pgp) and p53 protein. The invasive, high-grade, highly proliferative, p53- and Pgp-positive tumors were more resistant than the superficial, lower-grade, p53- and Pgp-negative tumors. All tumors were negative for bcl-2. The rank order of these factors was p53 expression > tumor stage > grade > bromodeoxyuridine labeling index > Pgp. Statistical analysis using the Akaike Information Criterion indicates that the two-parameter combination of p53 expression with stage further improved the predictive value. The present study shows that: (a) there was a >700-fold difference in doxorubicin sensitivity among superficial and invasive tumors; (b) the variable and incomplete response of superficial bladder cancer to intravesical doxorubicin therapy is likely due to the 35-fold variability in tumor chemosensitivity and, to a lesser degree, the 4-fold variability in tissue pharmacokinetics; (c) the lack of response of invasive cancer to intravesical doxorubicin therapy is likely the result of the inadequate drug concentrations presented to the deep muscle layers and the low chemosensitivity of the more aggressive tumors; and (d) the combination of p53 expression and high stage was the most significant predictor of doxorubicin sensitivity, whereas Pgp expression was the least important.
 ...
PMID:Pharmacodynamics of doxorubicin in human bladder tumors. 981 97

A patient with ulcerative colitis, extensive dysplasia, multifocal colon cancer, and an appendiceal cystadenoma is described. A 48-year-old man with a 26-year history of ulcerative colitis (UC) had extensive dysplasia involving nearly the entire colon and four dysplasia-associated mass lesions (DALMs). Four invasive adenocarcinomas were present. This case is the first documentation of a DALM (mucinous cystadenoma) arising in the appendix in the setting of UC. The genetic alterations present in the various lesions were analyzed. The molecular profiles of the neoplastic lesions differed. Mutations were found in p53 and ras genes, and one site showed microsatellite instability in a single genetic locus. These molecular abnormalities develop before invasive cancer develops, and may undergo clonal expansion to create large mucosal patches containing certain cells with genetic alterations. The diversity of the early changes suggests that the recurrent inflammation characteristic of long-standing UC randomly damages genes known to participate in colon carcinogenesis and that it affects multiple target genes. The findings also support a multiclonal origin of synchronous tumors because the molecular phenotypes of the preinvasive lesions differed at various sites.
 ...
PMID:Multifocal neoplasia involving the colon and appendix in ulcerative colitis: pathological and molecular features. 983 86

Expression of proliferation- and apoptosis-related proteins was studied by immunohistochemistry in 130 usual ductal hyperplasias of the breast, of which 39 cases (30%) had adjacent invasive cancer. Overexpression of cyclin D1 and Ki-67 was found in 6% and 29% of the cases, respectively. Only two mild ductal hyperplasias were Her-2/neu positive. Overexpression of p21 and reduced expression of p27, both cdk-inhibitors, was seen in 16% and 27% of the lesions, respectively. Reduced expression of bcl-2 was found in 16% of the cases, and p53 accumulation was present in 8%. Expression of six of the seven studied proteins showed no significant difference between mild, moderate, or florid ductal hyperplasias, indicating that there are no important cell biological differences with regard to the studied proteins between the lesions within this morphologically continuous spectrum. In addition, there were no differences between lesions with and without an invasive component. Cyclin D1 positivity was exclusively seen in lesions with 75% or more p27-positive nuclei. No significant correlations were found between other proteins. Twenty-three of 91 lesions (25%) had multiple events, of which five showed altered expressions of three or four proteins. In conclusion, altered protein expression of several proliferation- and apoptosis-related genes that are known to be involved in invasive breast cancer also may be found in usual ductal hyperplastic lesions, including several lesions with multiple events. This implies that usual ductal hyperplastic lesions may be among the earliest lesions within the breast oncogenetic spectrum.
 ...
PMID:Expression of proliferation and apoptosis-related proteins in usual ductal hyperplasia of the breast. 986 45

Precise correlation of histomorphology with the results of molecular genetic analysis is difficult in gastric cancer tissue composed of intestinal and diffuse types. A novel microdissection procedure was applied to correlate p53 and APC allelic loss with histologic type and tumor stage (mucosal vs. invasive cancer) in formalin-fixed, paraffin-embedded specimens of 25 gastric cancers. In addition, mucosal and invasive lesions were dissected from each of 11 invasive gastric cancers to study progression, and allelic loss of the p53 and APC genes was assessed. The p53 gene underwent loss of heterozygosity (LOH) in 4 of 4 informative cases of intestinal-type gastric cancer with mucosal lesions associated with invasion. By contrast, no p53 LOH was found among 6 informative cases with mucosal cancer. LOH of the APC gene in both intestinal and diffuse types of cancer was detected in 4 of 7 and 5 of 6 informative cases, respectively. These data suggest that allelic deletion of the p53 gene in intestinal-type gastric carcinoma predicts the invasive potential of mucosal cancer, and that inactivation of the APC gene plays a role in the genetic tumorigenesis of both intestinal and diffuse types of gastric cancer. Microdissection can correlate genetic alterations with histologic morphology in gastric cancer.
 ...
PMID:Correlation of histologic morphology and tumor stage with molecular genetic analysis using microdissection in gastric carcinomas. 999 Apr 80


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