Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty-nine primary breast carcinomas and 11 metastases were examined to identify genetic alterations in the tumour suppressor gene regions 3p, 11p, 13q, 17p, and 17q. Loss of heterozygosity (LOH) was frequently observed on chromosome arms 17p (p144D6 lost in 75%, pYNZ22.1 in 55%, and TP53 in 48% of the primary tumours), 13q (RBI lost in 40% of the primary tumours), and 17q (pRMU3 lost in 35%, pTHH59 in 29%, and NM23HI in 26% of the primary tumours). Loss of all the markers except p144D6 was observed even more frequently in the metastases. Pairwise comparisons for concordance of allele losses on 17p indicated that there might be two genes on 17p implicated in breast cancer development; the TP53 gene and a gene located close to the p144D6 and pYNZ22.1 markers. LOH of the RBI gene was associated with LOH of pYNZ22.1 and p144D6, but not with LOH of TP53. LOH of RBI and TP53 was associated with occurrence of ductal carcinomas, RBI and p144D6 losses with tumour size, and p144D6 losses with positive node status as well. LOH of TP53 and the three 17q markers NM23HI, pTHH59, and pRMU3 was most frequently observed in tumours from postmenopausal women. p144D6 losses occurred most frequently in progesterone receptor-negative tumours, whereas pTHH59 losses occurred most frequently in oestrogen receptor-negative tumours. LOH of the investigated loci was not associated with ERBB2 protooncogene amplification, with positive family history of breast cancer, or with survival.
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PMID:Genetic alterations of the tumour suppressor gene regions 3p, 11p, 13q, 17p, and 17q in human breast carcinomas. 137 10

c-erbB-2 gene amplification and protein over-expression were investigated in 89 primary tumours and 24 metastases from Norwegian breast cancer patients. Amplification occurred in 22.5% of the primary tumours and 50% of the metastases. The amplification was negatively correlated to the oestrogen receptor (ER) content in both the primary tumours and the metastases. No significant differences between amplified and non-amplified tumours were observed with regard to node status, clinical stage, tumour size or menopausal status, although correlations of borderline significance were found between node status, clinical stage and high degree of gene amplification. All the amplified tumours were of the invasive ductal type. Follow-up data of patients observed for more than 1 year showed a significantly higher recurrence rate in the c-erbB-2 amplified group. Allele loss of chromosome 17p and of 7q was seen in 55% and 48% of the tumours respectively. No significant correlation was found between these losses and clinico-histological parameters. More than 50% of the tumours with a loss of 17q sequences had an amplification of c-erbB-2 which is located on 17q12-21, indicating that only one of the chromosomes may be involved in the amplification of the c-erbB-2. A trend towards a correlation between loss of 17q and high degree of amplification were found. No correlation was found between positive family history of breast cancer and c-erbB-2 gene amplification, nor loss of 17p or 17q sequences. Our data support the hypothesis that amplification correlates with aggressive tumour behaviour, and thus may be used as a prognostic factor in breast carcinomas. The allele losses on 17p and 17q points to tumour suppressor gene or genes on this chromosome, although not as predisposing genes in families.
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PMID:Amplification and protein over-expression of the neu/HER-2/c-erbB-2 protooncogene in human breast carcinomas: relationship to loss of gene sequences on chromosome 17, family history and prognosis. 197 66

In a study of DNAs from 100 breast cancer patients and 100 controls, there were no differences in the frequencies of common or rare alleles at the Harvey ras (c-Ha-ras) locus on chromosome 11. However, one Ha-ras allele was deleted from the tumour DNA in 14 of 65 informative patients. Loss of a Ha-ras allele correlates with paucity of oestrogen receptor protein and with increased tumour size at presentation, but is not associated with microscopic evidence of lymph node invasion. The findings on Ha-ras and other informative loci are consistent with the possibility that a tumour suppressor gene involved in the early stages of breast cancer is located on the short arm of chromosome 11.
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PMID:Partial deletion of chromosome 11p in breast cancer correlates with size of primary tumour and oestrogen receptor level. 306 95

The p53 gene product is a tumour suppressor protein, and alterations of the protein are common in human cancer. Previous studies have focused on nuclear accumulation of p53. To investigate if cytoplasmic accumulation of p53 strengthens the relationships to different pathobiological variables and distant recurrence-free survival in breast cancer, tumours from 164 stage II patients were examined with the monoclonal antibody PAb1801. Nine per cent of the tumours were nuclear positive and 21% were cytoplasmic positive. Cellular p53 accumulation, related to the nucleus or the cytoplasm or both, showed stronger associations with pathobiological variables than nuclear accumulation alone. Accumulation of p53 was significantly correlated to tumour size over 20 mm, negative oestrogen receptor (ER) status, DNA aneuploidy, high S-phase fraction and positive erbB-2 status. Cytoplasmic p53 was significantly correlated to distance recurrence-free survival in patients negative for nuclear p53 (P < 0.0001). Cellular p53 accumulation was an independent prognostic factor, in addition to lymph node status and ER content. We conclude that consideration of cytoplasmic staining enhances the clinical importance of p53.
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PMID:Cellular accumulation of p53 protein: an independent prognostic factor in stage II breast cancer. 790 19

Investigation of genetic changes in tumours by loss of heterozygosity (LOH) is a powerful technique for identifying chromosomal regions that may contain tumour suppressor genes. LOH has been described on chromosome 6 in ovarian carcinoma using restriction fragment length polymorphism analysis with a small number of probes. We studied 29 ovarian carcinomas with 19 probes mapping to chromosome 6. Sixteen of the 29 tumours showed LOH on 6q (55%). Of these 16, 63% showed loss of all informative markers on that arm. One tumour showed loss of 6q24-qter, localising the putative tumour suppressor gene to that region. Loss on 6p was 28% overall. However, using three dinucleotide repeat primer pairs from 6p to study LOH in seven selected tumours, LOH was demonstrated at both 6p22.3-pter and at 6p12-6p22. These results confirm that 6q harbours a tumour suppressor gene of relevance to ovarian carcinoma and suggest that there may also be a similar gene(s) on 6p. By Southern analysis, there was no evidence of genomic rearrangements of the oestrogen receptor gene, located at 6q25.1. LOH on 6q was more common in high than low grade tumours. The relevance of our findings to previous work in ovarian cancer and other solid tumours is discussed.
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PMID:Frequent loss of heterozygosity on chromosome 6 in human ovarian carcinoma. 809 76

The immunohistochemical expression of p53 and c-erbB-2 gene proteins was examined in a series of 130 breast adenocarcinomas. This study intended to investigate whether the frequency of the altered expression of the tumour suppressor gene p53 and the overexpression of the oncogene c-erbB-2 in breast cancer tissue cells correlated with other variables known to affect the biological behaviour of these tumours and the overall survival of the patients (median follow-up time: 6 years). The expression of p53 protein and c-erbB-2 gene product was evaluated immunohistochemically. Expression of p53 protein was detected in 30 (23 per cent) of the neoplasms examined, while 26 (20 per cent) out of the 130 cases demonstrated positive c-erbB-2 immunoreactivity. There was a statistically significant association between p53 protein expression and primary tumour size, lymph node involvement, and oestrogen receptor positivity. The incidence of c-erbB-2 positivity was significantly correlated with high tumour grade, axillary node invasion, large tumour size, and the absence of steroid receptors. p53 immuno-expression was clearly associated with c-erbB-2 protein overexpression. Concomitant p53 and c-erbB-2 positive immunolabelling, which emerged in 14 out of the 130 cases (10.7 per cent), was clearly associated with high grade, large size, positive nodal status, ductal infiltrating (NOS) histological type, and low values of progesterone receptors. Overall survival of patients was not significantly related to the immunoreactivity of either p53 or c-erbB-2 considered separately, whereas there was a clearly significant trend to worse overall prognosis in cancers with double p53/c-erbB-2 positive phenotype. The simultaneous immunodetection of p53/c-erbB-2 appears to have greater negative prognostic relevance than their separate expression.
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PMID:Prognostic significance of the co-expression of p53 and c-erbB-2 proteins in breast cancer. 869 41

Genetic alterations of tumour suppressor genes, for which loss of heterozygosity (LOH) is one mechanism of gene inactivation, are important steps in the development of endometrial cancer. To investigate the clinical relevance of LOH of BRCA1 (17q21), TP53 (17p13) and TCRD (14q11) in endometrial cancer, polymerase chain reaction (PCR)-based fluorescent DNA technology for the detection of microsatellite polymorphisms was applied. One hundred and thirteen archival endometrial cancer samples with matched normal tissues were examined. Allele loss at three loci were correlated with age, tumour size, lymph node status, metastases, stage, histological types, grade, expression of oestrogen receptor (ER) and progesterone receptor (PgR), family history of cancer, previous history of cancer or precursor lesions, and previous history of hormone replacement therapy (HRT). LOH for BRCA1 was detected in 18.1%, of TP53 in 26.9%, and of TCRD in 26.3% of informative cases. LOH of BRCA1 correlated with medium grade, positive ER status, and family history of cancer; LOH of TP53 correlated with younger age, high grade, positive PgR status, and with tumours from patients without HRT; LOH of TCRD correlated only with family history of cancer. LOH at all three loci correlated only with grade and positive family history. Allele loss of one of the three tumour suppressor loci did not correlate with disease-free survival (DFS), but LOH of BRCA1 correlated significantly with decreased overall survival (OS). The latter, together with the correlation of LOH of BRCA1 locus with steroid hormone receptor expression, might give a hint to the potential involvement of the co-localised 17 beta-hydroxysteroid dehydrogenase (HSD) gene in the development of endometrial cancer.
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PMID:Loss of heterozygosity of BRCA1, TP53 and TCRD markers analysed in sporadic endometrial cancer. 989 67

Tumour suppressor genes and oncogenes that control proliferation and apoptosis are known to play an important role in embryogenesis, second trimester fetal oocyte loss, adult ovulation, and in adult male testicular degeneration. We have examined tumour suppressor genes, oncogenes and oestrogen receptors during first trimester human gonadal differentiation to investigate their role at this crucial phase in development. Immunohistochemistry was used to localize the gene products of Bcl-2, c-erB-2, c-myc, p53, nm23 and oestrogen receptor. As gonadal development occurred at 6-12 weeks gestation, a changing pattern of expression was observed that varied in different cell types. The oestrogen receptor was not present in oogonia, spermatogonia and supporting cells during the first trimester. This study highlights the importance of oncogenes and tumour suppressor genes in first trimester gonadal development.
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PMID:Oncogenes and tumour suppressor genes in first trimester human fetal gonadal development. 1042 1

Chromosome 17p is among the most frequently deleted regions in a variety of human malignancies including breast cancer. This study has further refined the localization of a putative tumour suppressor gene (TSG) at 17p13 distal to the TP53 gene in breast carcinomas. It was found that 73% (37 of 51) of the breast tumours exhibited loss of heterozygosity (LOH) at one or more loci at 17p13. The allelic loss patterns of these tumours suggest the presence of at least seven commonly deleted regions on 17p13. The three most frequently deleted regions were mapped at chromosomal location 17p13.3-17p13.2 between the markers D17S831 and D17S1845 (56% LOH), at 17p13.1 between D17S1810 and D17S1832 (53% LOH), and at 17p13.1 between D17S938 and TP53 (55% LOH). A significant correlation was found between loss at 17p13 and tumour grade, size, proliferative activity, and oestrogen receptor (ER) status. Losses at 17p13 were seen more frequently in large and poorly differentiated tumours with high proliferative activity. These data support and extend previous reports on the presence of a putative TSG(s) at chromosomal region 17p13 distal to the TP53 gene and show that different subsets of LOH are associated with more aggressive tumour behaviour.
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PMID:Detailed deletion mapping in sporadic breast cancer at chromosomal region 17p13 distal to the TP53 gene: association with clinicopathological parameters. 1143 64

Pivotal genetic information has been derived for a host of rare genetic disorders, but progress has been much slower in relation to the common causes of female infertility. In this chapter, we shall illustrate the approaches being applied in elucidating conditions causing infertility that are inherited in a polygenic/multifactorial fashion. The task is to determine the number of genes responsible and their chromosomal location(s). The first approach is to use genome-wide quantitative linkage analysis, searching throughout the genome with no prior expectation that a given gene or chromosomal region is casually involved. A second approach is to search across the genome for altered gene expression, for example comparing endometriosis and normal (non-endometriosis)cells. The third approach is less indiscriminate and more focused, depending upon identifying specific candidate genes. Aromatase, calhedrin, oestrogen receptor, galactose-1-phosphate uridyl transferase (GALT) and tumour suppressor genes such as p53 are attractive candidate genes for endometriosis. Endometriosis, which has long been suspected to possess a familial tendency, has been subjected to genome-wide linkage analysis in Oxford, UK, where sib-pair analysis uses polymorphic DNA markers and fluorescence-based automated analysis. Several regions of exclusion have been found, but no linkages have so far been reported. A candidate gene approach focuses on the presence of chromosomal aberrations, the assumption being that endometriosis parallels neoplasia. At Baylor College of Medicine, we thus began by showing chromosome alterations involving trisomy 11, monosomy 16 and monosomy 17 in late-stage endometriosis. A loss of only the p53 tumour suppressor gene, rather than a loss (monosomy) of chromosome 17 per se, however, seems to be the pivotal event. A second representative polygenic/multifactorial disorder causing female infertility is polycystic ovarian syndrome. Both quantitative linkage analysis and candidate gene approaches are being pursued. In the far more commonly observed 'idiopathic' variety (non-adrenal polycystic ovarian syndrome and hirsutism), consensus has long existed that one or more dominant genes causes the condition. Although the mode of inheritance in 'essential' polycystic ovarian syndrome remains uncertain, dominant tendencies are clearly more pertinent than recessive ones. Genes for adrenal biosynthetic enzymes, insulin receptors, leptin and leptin receptors, follistatin, activin and inhibins are attractive candidates for polycystic ovarian disease. A linkage to 37 candidate genes was sought using affected sib-pair analysis and transmission/disequilibrium methods.
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PMID:Molecular approach to common causes of female infertility. 1247 48


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