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

Extensive research has led to accumulation of common hereditary evidence concerning ovarian and breast cancer, suggesting that these two cancers can be considered as one type. Subsequently, women with breast cancer are susceptible to the risk of developing ovarian cancer. Highly expressed oncogenes such as bcl-2, HER2/neu and others or mutated suppressor genes such as p53 or BRCA1 have been characterised as hereditary susceptibility genes leading to syndromes such as breast/ovarian cancer syndrome, Li-Fraumeni and others. Furthermore, these genetic alterations can cause potent chemoresistance by inhibiting induction of apoptosis after DNA damage caused by chemotherapy and/or radiotherapy. Presently, molecular onco-biology has enabled us not only to detect susceptibility to ovarian and breast cancer but also ways to inhibit their further progression or even circumventing chemoresistance mechanisms after their development by gene therapy using delivery vectors such as liposomes or viruses, by which we can replace wild-type tumour suppressor genes or by using antigene, antisense oligonucleotides and antisense RNA leading to reduced oncogene expression, enabling induction of apoptosis after DNA damage into chemoresistant tumour cells. Furthermore efflux-genes such as MDR-1 or MRP can be circumvented, suicide-genes can be employed which can facilitate sensitivity by encoding enzymes capable of converting inactive forms of a drug into toxic antimetabolites and immunotherapy can be achieved, by transfection of tumour cells with adenoviral vectors encoding immunomodulators such as IL-2 or MHC molecules. Thus, molecular biology appears to be a very strong element for the screening, diagnosis, therapy and prognosis of ovarian and breast cancer. However, consistent future research is greatly needed because many points concerning ovarian and breast cancer genetics are still unknown. Finally, we strongly believe that gene therapy could be extremely useful when is combined with conventional therapy against ovarian and breast tumours.
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PMID:Molecular aspects of breast and ovarian cancer. 937 59

Breast cancer patients usually do not die of their primary cancers; they die of metastatic disease. Thus understanding the progression of breast cancer to the metastatic state and the changes that take place in highly malignant breast cells are important goals that could eventually result in new therapeutic approaches to highly progressive breast disease. Changes in the expression of certain genes or alterations in gene structures and encoded products can result in benign tumour cells progressing to the metastatic state. Experimentally, this has been performed by transferring dominantly acting oncogenes into susceptible cells and then testing the malignant properties of these cells in suitable animal models, but such rapid qualitative changes occur in vivo only rarely, and the natural progression of mammary cells to the metastatic state is thought to occur through a slow stepwise process that can take several years. Some of the slow stepwise changes in mammary cancer progression can be reversible and need not involve dominantly acting oncogenes or tumour suppressor genes, consistent with clinical observations. An important element of the natural progression of mammary tumours to malignancy may be their ability to circumvent microenvironmental controls that regulate growth and cellular diversity, a process that appears to involve mainly quantitative changes in gene expression, resulting in loss of normal cellular regulation. One of the important mechanisms of cellular regulation in epithelial tissues, such as those found in the breast, is mediated by intercellular junctional communication. Alterations in gene expression can result in loss of gap-junctional communication, concomitant with cellular diversification and progression. It is thought that the highly malignant cancer cells that have slowly evolved in vivo with only a few qualitative changes in gene structure have undergone extensive cycles of diversification and the accumulation of several quantitative changes in the expression of various genes that encode products related to malignancy. We have identified some of the genes that are related to progression and metastasis in breast cancer. For example, one of these genes, a novel gene called mta1 (in rodents) or MTA1 (in humans) appears to be involved in mammary cell motility and growth regulation. Thus highly malignant cellular phenotypes can arise rapidly due to specific qualitative changes in critical controlling genes, or more slowly via less critical qualitative genetic changes coupled with other cellular changes, such as loss of intercellular communication, and changes in gene expression, such as in the MTA1 gene, resulting in cellular diversification and ultimately tumour progression to the metastatic state.
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PMID:Breast cancer metastasis-associated genes: role in tumour progression to the metastatic state. 951 27

Loss of genetic material on chromosomes 13q and 17 has been suggested to be of importance in the initiation and progression of female breast cancer, but their involvement is less well illustrated in male breast carcinomas. The present study was designed to investigate the incidence of allelic loss and microsatellite instability for chromosomes 13q, 17p and 17q in 13 sporadic male breast carcinomas using matched normal-tumour DNA samples and seven polymorphic microsatellite markers. Genetic imbalance was found in one or more informative markers in 85% of the patients, with more frequent loss of heterozygosity and microsatellite instability at loci on chromosome 13q. Thus, a high incidence of allelic losses was observed at the retinoblastoma gene (4/6) and likewise at the D13S263 locus (7/12), which also exhibited the highest frequency of microsatellite instability. The intragenic microsatellite in intron 1 of the TP53 gene on chromosome 17p revealed loss of heterozygosity in 3 of 8 informative patients. The investigated proximal region of chromosome 13q is postulated to harbour several potential tumour suppressor genes associated with female breast cancer. The high incidence of allelic losses at the D13S263 microsatellite, located distal to both the BRCA2 and the Brush-1 loci but proximal to the retinoblastoma gene, possibly indicates the presence of an additional tumour suppressor gene which may be involved in male breast carcinomas. However, this hypothesis needs verification in an extended study of male breast carcinomas.
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PMID:Frequent allelic losses on chromosome 13q in human male breast carcinomas. 961 88

The breast cancer specific tumour suppressor protein, BRCA1 (refs 1,2), activates transcription when linked with a DNA-binding domain and is a component of the RNA polymerase II (Pol II) holoenzyme. We show here that RNA helicase A (RHA) protein links BRCA1 to the holoenzyme complex. The region of BRCA1 which interacts with RHA and, thus, the holoenzyme complex, corresponds to subregions of the BRCT domain of BRCA1 (ref. 9). This interaction was shown to occur in yeast nuclei, and expression in human cells of a truncated RHA molecule which retains binding to BRCA1 inhibited transcriptional activation mediated by the BRCA1 carboxy terminus. These data are the first to identify a specific protein interaction with the BRCA1 C-terminal domain and are consistent with the model that BRCA1 functions as a transcriptional coactivator.
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PMID:BRCA1 protein is linked to the RNA polymerase II holoenzyme complex via RNA helicase A. 966 97

Matrix metalloproteinases (MMPs) are a group of enzymes thought to be responsible for both normal connective tissue matrix remodelling and accelerated breakdown associated with tumour development. The current study aimed to investigate the immunohistochemical expression of matrix metalloproteinase 3 (MMP-3, stromelysin-1) in correlation with the expression of Basement Membrane (BM) antigen (type IV collagen, laminin), fibronectin, cathepsin D, p53, c-erbB-2, proliferative activity (Ki-67, PCNA), steroid receptor content as well as to the other conventional clinicopathological parameters in breast cancer. This study was performed on a series of frozen and paraffin sections from 84 breast cancer specimens by immunohistochemistry using the monoclonal antibody MMP-3 (Ab-1). Stromelysin-1 (ST1) was observed in about 10% of epithelial cells in the control groups (cases of fibrocystic and benign proliferative breast disease), while expression (> 10% of expression) was detected in 89.7% of tumours. The expression of ST1 in carcinoma cells was strongly associated with its presence in the stroma (p < 0.001). A significantly positive correlation was found between ST1 expression, and p53 tumour suppressor gene product (p = 0.004), and a relationship with c-erbB-2 protein and progesterone receptor status was also indicated. These findings suggest that ST1 expression in breast cancer tissue is irrespective of the expression of the extracellular matrix component, the proteolytic enzyme cathepsin D and the growth fraction of the tumour, and that it could be a potential new prognostic marker in breast cancer.
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PMID:Matrix metalloproteinase expression in human breast cancer: an immunohistochemical study including correlation with cathepsin D, type IV collagen, laminin, fibronectin, EGFR, c-erbB-2 oncoprotein, p53, steroid receptors status and proliferative indices. 967 87

The presence of BRCA1 protein was determined immunohistochemically in normal and benign breast biopsies, non-familial breast carcinomas and breast carcinomas from one or more individuals from 8 BRCA1 families. Strikingly, little staining was detected in breast carcinomas from BRCA1 families, regardless of the position or type of mutation, whereas strong immunostaining was observed in 28/28 of non-malignant breast biopsies. Furthermore, BRCA1 staining was reduced in non-familial breast carcinomas, since loss of nuclear BRCA1 staining was evident in 19% of non-familial breast carcinomas whilst a similar proportion (20%) showed absence of either cytoplasmic or nuclear BRCA1 staining. Statistical analysis indicates that breast cancer is characterised by a reduction in levels of nuclear BRCA1 in familial (p < 0.001) and non-familial breast cancer (p = 0.001). In non-familial breast cancer absence of nuclear BRCA1, but not cytoplasmic BRCA1, is more common in high grade breast carcinomas (p = 0.03) and in patients with evidence of lymph node involvement (p = 0.05). Correlation between the absence of BRCA1 protein with high grade is consistent with previous findings of a correlation between mutations in the BRCA1 gene and high grade. Our findings provide new evidence in support of BRCA1 as a tumour suppressor protein in non-familial breast cancer.
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PMID:An important role for BRCA1 in breast cancer progression is indicated by its loss in a large proportion of non-familial breast cancers. 969 23

Prognostic factors, e.g. metastatic disease, lymph node status, tumour size, histologic grade, estrogen and progesterone receptors, and markers of proliferation are used to predict the clinical course of breast cancer at the time of primary treatment. Patients with a poor prognosis are offered adjuvant therapy. For the choice of adjuvant therapy (endocrine or cytotoxic) treatment predictive factors, e.g. estrogen and progesterone receptor; are useful. Putative new prognostic factors (e.g. oncogenes, tumour suppressor genes, and invasive factors) should be evaluated together with the clinical established factors in multivariate analyses.
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PMID:Prognostic factors in breast cancer: a brief review. 970 79

Approximately ten percent of patients with malignant melanoma have family histories of the disease, suggesting a genetic predisposition. Germline mutations in tumour suppressor p16 gene have been implicated as disease causing mutations in some of the melanoma families. The frequency of families with p16 germline mutations among melanoma prone families varies from eight to fifty percent. The range of the variability is influenced apparently by the number of melanoma affected individuals within the family, as well as by other, yet unidentified factors. Ethnic background is known to determine both the frequency and the nature of germline alterations. Recently, specific mutations in tumour suppressor genes involved in breast cancer and in colon cancer were found at elevated frequency among Ashkenazi Jews. This report describes results of a screening for p16 germline alterations in a collection of Israeli melanoma families. We have analyzed genomic DNA from thirty one Ashkenazi and non-Ashkenazi Jewish melanoma families, as well as from thirty melanoma patients without an apparent family history of the disease. The entire coding region of the p16 gene was screened by single strand conformation polymorphism analysis and direct DNA sequencing. We have detected a number of carriers with the Ala148 Thr polymorphism at the end of the second exon and several instances of 500(G=>C) substitution at the 3' untranslated portion of the gene.
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PMID:Screening for tumour suppressor p16(CDKN2A) germline mutations in Israeli melanoma families. 980 78

TSG101 is a recently identified putative tumour suppressor gene which has been implicated in human breast cancer. To address whether germline disruption of TSG101 predisposes individuals to this disease, we analysed genomic DNA and mRNA isolated from peripheral blood from 20 familial breast cancer cases. No evidence of large intragenic insertions/deletions or point mutations in TSG101 was found by Southern blot analysis and sequence analysis of the entire coding region. However, in 11 of 20 samples, 'aberrant' transcripts were detected. Sequence analysis suggested that these variants were generated by the use of different cryptic splicing sites. Such alternative/aberrant splicing events were not restricted to cancer patients, but were also detected in peripheral blood of non-cancer patients and in normal tissues.
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PMID:Truncated TSG101 transcripts are present in peripheral blood from both familial breast cancer patients and controls. 984 57

The gene mutated in ataxia telangiectasia (ATM) has an established tumour suppressor role in breast cancer. ATM appears to be expressed in most normal cells, including breast epithelium, where it has been postulated to have a nuclear role in cell cycle regulation following DNA damage. However, ATM is not upregulated after DNA damage. In this study, we demonstrate an absence of immunohistologically detectable levels of ATM in the normally quiescent myoepithelial cells that line normal breast ducts. This contrasts dramatically with the significant expression of ATM in the proliferative myoepithelium of sclerosing adenosis (n = 7). This upregulation of ATM suggests that ATM expression is coupled to the proliferative status of the myoepithelium. Our results also indicate that there are factors other than ATM gene mutations that can dramatically influence ATM expression in the breast and that these factors should be considered for their possible implications in carcinogenesis.
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PMID:Upregulation of ATM in sclerosing adenosis of the breast. 989 51


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