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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic alterations of multiple loci that serve as markers for the induction and progression of disease have been identified in several adenocarcinomas, but not in adenocarcinoma of the prostate. To determine if similar genetic alterations occur in prostate carcinoma and could serve as markers for the extent of clinical disease, we have examined 23 predominantly moderately-differentiated, localized prostate carcinomas and one prostatic dysplasia for changes in the structure and copy number of ten selected genes. These genes include 1) those important to androgen metabolism in the prostate, the androgen receptor and steroid 5 alpha reductase genes; 2) those that map to the 10q (PLAU) and 7q (MET) chromosomal regions found deleted in some prostate carcinomas, and 3) proto-oncogenes (ERBB2, INT2, and MYC) and tumor suppressor gene loci (RB1, TP53 and D17S5) found altered in adenocarcinomas of the breast, colon and lung. Gene alterations were detected in one specimen, a lymph node metastasis from a poorly differentiated tumor. This specimen exhibited loss of heterozygosity for two loci putatively active in tumor suppression, TP53 and D17S5, on the short arm of chromosome 17. This study indicates that gross genetic alterations were not evident and could not be used as markers of tumor development in well- or moderately-differentiated, localized lesions, but that loss of the 17p region may be a useful marker for advanced carcinomas in the prostate.
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PMID:Loss of the 17p chromosomal region in a metastatic carcinoma of the prostate. 155 12

Oncogene dosage and expression were studied in 16 testicular neoplasms, 14 of germ cell and two of non-germ cell origin. In comparison with normal DNA, tumour DNA of a total of eight patients (seven with germ cell neoplasm and one with testicular lymphoma) showed increased dosages of KRAS2, PDGFA, EGFR, MET and PDGFB. The most frequent (occurring in six tumours) and prominent (up to 3-4-fold) increases were detected in the dosages of KRAS2 (on chromosome 12p) and PDGFA (chromosome 7p), relative to a reference locus from chromosome 2. Importantly, there was a similar increase in 12p dosage in general in these tumours, suggesting the presence of the characteristic isochromosome 12p marker. On the contrary, possible 7p polysomy (assessed by molecular methods) did not explain the PDGFA (or EGFR) changes in all cases. NRAS, MYCN, CSFIR, MYB, MYC, ABL, HRASI, TP53, and ERBB2 did not reveal any consistent alterations in tumour DNA. In RNA dot blot assays the expression of KRAS2, PDGFA, EGFR, or MYC was generally not increased in the tumour samples when compared to that in normal testicular tissue of the same patients although there was interindividual variation in mRNA levels. It thus appears that while oncogene dosage changes occur in a proportion of testis cancers, they are often part of changes in large chromosomal regions or whole arms and are seldom accompanied by altered expression.
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PMID:Oncogenes in human testicular cancer: DNA and RNA studies. 182 52

Based on the high incidence of loss of heterozygosity for loci on chromosome 17p in the vicinity of the p53 locus in human breast tumors, we investigated the frequency and effects of mutations in the p53 tumor suppressor gene in mammary neoplasia. We examined the p53 gene in 20 breast cancer cell lines and 59 primary breast tumors. Northern blot analysis, immunoprecipitation, and nucleotide sequencing analysis revealed aberrant mRNA expression, over-expression of protein, and point mutations in the p53 gene in 50% of the cell lines tested. A multiplex PCR assay was developed to search for deletions in the p53 genomic locus. Multiplex PCR of genomic DNA showed that up to 36% of primary tumors contained aberrations in the p53 locus. Mutations in exons 5-9 of the p53 gene were found in 10 out of 59 (17%) of the primary tumors studies by single-stranded conformation polymorphism analysis. We conclude that, compared to amplification of HER2/NEU, MYC, or INT2 oncogene loci, p53 gene mutations and deletions are the most frequently observed genetic change in breast cancer related to a single gene. Correlated to disease status, p53 gene mutations could prove to be a valuable marker for diagnosis and/or prognosis of breast neoplasia.
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PMID:Mutations in p53 as potential molecular markers for human breast cancer. 196 33

Several proto-oncogenes have been reported to be expressed in normal and malignant hematopoietic cells. Since these studies have been done almost exclusively by Northern and dot-blot analyses using mixed populations of cells, any conclusions concerning quantitative changes in gene expression are difficult to document. We have developed a rapid and sensitive RNA-in situ hybridization technique permitting detection of as few as 5 copies of mRNA per individual cell. Using this technique we have studied the expression levels of several oncogenes including MYC, SIS, FMS, p53, FOS and RAF in both normal hematopoietic cells and bone marrow (BM) cells obtained from acute myelogenous leukemia (AML) patients at presentation, at relapse and in complete remission (CR). Two of these oncogenes, MYC and SIS, are expressed at levels at least 2-5-fold higher in hematopoietic cells obtained from leukemia patients than in any normal hematopoietic cell examined, including cells obtained from regenerating bone marrow. The proportion of abnormal cells correlated well with the percentage of blast cells determined by morphological examination. In 7 out of 10 AML patients in morphological remission, a subpopulation of cells is detectable with abnormally high levels of MYC and/or SIS mRNA. These high levels of MYC expression are similar to those found in BM cells obtained from AML patients at presentation or relapse, but the percentage of cells with this abnormality is generally much lower. Continued follow-up of these patients has shown that 5 of them relapsed within 8 months. At this time, none of the 3 patients which were negative for MYC overexpression has relapsed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of minimal residual disease in acute myelogenous leukemia by RNA-in situ hybridization. 265 88

Identification of the genetic alterations that occur in tumors is an important approach to understanding tumorigenesis. We have used comparative genomic hybridization (CGH), a novel molecular cytogenetic method, to identify the gross DNA copy number changes that commonly occur in small cell lung cancer (SCLC). We analyzed ten SCLC tumors (seven primary tumors and three metastases) from eight patients. We found frequent increases in DNA copy number on chromosome arms 5p, 8q, 3q, and Xq and frequent decreases in copy number on chromosome arms 3p, 17p, 5q, 8p, 13q, and 4p. The increase in copy number at 8q24 (MYC) and decreases at 17p13 (TP53), 13q14 (RB), and 3p have previously been identified in SCLC with other methods. Many of the other regions in which we detected common copy number changes have not been reported to be regions of common alteration in SCLC tumors. Comparison of copy number changes between a primary tumor and a metastasis from the same patient showed that they were more closely related to each other than to any of the other tumors. The results of direct CGH analysis of SCLC tumors reported here confirm the existence of copy number changes that we identified previously by using cell lines.
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PMID:Identification of novel regions of altered DNA copy number in small cell lung tumors. 766 37

Transcripts coding for transcription factors (RB, P53, FOS, MYC, MYB, ERBA, REL), growth factors (FGF1, FGF2, INT2, TGFA, TGFB, PDGF, IGF1, IGF2), interleukins, (IL1, IL2, IL3, IL4, IL6, TNF), growth-factor receptors or cytosolic protein kinases (RAF, PIM, FES, MET, SRC, ROS, TRK, KIT, CSFR, IGFR, PDGFR, EGFR, NEU) were quantified in cultured human mammary fibroblasts from normal tissues, benign tumours, carcinomas and post-radiation fibrosis lesions by slot-blot autoradiography and image analysis. The effects of a differentiating agent (cholera toxin) and of a tumour promoter (12-O-tetradecanoyl-phorbol-13-acetate) were also examined. The drugs modulated the levels of the anti-oncogene transcripts (RB, P53) and of ERBA, REL, RAF, MET, ROS, TRK, CSFR, EGFR, NEU, FGF1, INT2, IGF1, IL1, IL2, IL4 and IL6. Apart from this variation, there were multiple differences in gene expression among normal and pathological cells (concerning all but P53, TGFB and interleukin transcripts) and between sub-types defined by the presence of alpha-sm-actin (myofibroblasts) or EDB-fibronectin (RAF, ROS, FES, KIT, IGFR, NEU, INT2, TGFB, PDGF, IGFs, ILs). It appears, therefore, that mammary stroma progress irreversibly along with the epithelium during tumoral development, and that breast cancer is not only a multi-gene but also a multi-tissue phenotype.
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PMID:Quantitative variation of proto-oncogene and cytokine gene expression in isolated breast fibroblasts. 776 44

Quantitative imbalance in chromosomal material relative to the normal diploid situation is the most conspicuous genetic change in breast tumors, affecting virtually all chromosomes in varying frequencies. This imbalance is reflected by deviant DNA stemlines observed in DNA flow cytometry analysis, by numerical chromosome abnormalities in karyotype analysis and by loss of heterozygosity in DNA polymorphism studies. Gene amplification might be caused by the same genetic mechanisms that cause these chromosomal abnormalities [134]. The number of known genes for which there is now good evidence for their role in the development of breast cancer is still limited, and basically restricted to TP53 and ERBB2. Clearly, the estrogen receptor, not discussed here, can be conjectured to be of importance in breast cancer development, yet the significance of the reported sequence variants [157] for hormone-independent growth is presently undetermined [158]. For many others, such as MYC, CCND1, EMS1, EGF, RB1, NME, DCC and prohibitin, the evidence is still largely circumstantial, or obtained only by in vitro studies on breast cancer cell lines. In many cases of chromosomal imbalance and certainly those affecting whole chromosomes or chromosome arms, it is unclear what their effect on tumor growth will be, because multiple potential candidate genes are located in the affected region. In addition, it is obvious that multiple chromosomes are affected simultaneously in a single tumor, but that the total set of chromosome changes varies in different tumors. This intra- and intertumor heterogeneity of chromosome involvement suggests that an unknown number of the observed abnormalities are not important for tumor development, but merely result from genetic instability. On the other hand, there is accumulating evidence, particularly from flow cytometry and allelotype studies reviewed here, to suggest that the genetic evolution associated with tumor development and progression does reach a stage of equilibrium despite the presence of extensive tumor heterogeneity. The number of genetic events found per tumor raises the question whether each event of heterozygosity loss represents the second step in the inactivation of a tumor suppressor gene. Also, LOH observed with polymorphic markers can sometimes be interpreted as allelic copy number gain instead of loss. Possibly, some of these allelic imbalances contribute to the tumorigenic process simply because they create a dosage effect in certain gene products [2]. This supposes that the sole presence of allelic imbalance at certain chromosomes is sufficient to provide selective growth advantage in certain cases.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Somatic genetic changes in human breast cancer. 781 70

To study genetic alterations related to the development and/or progression of breast carcinoma, we examined amplification of the ERBB2, INT2, and MYC genes, as well as loss of heterozygosity (LOH) at loci on 11p, 16q, 17p (D17S5 and TP53), 17q (D17S74 and NME1), and 18q by restriction fragment length polymorphism analysis. The subjects were 26 patients with small breast carcinomas (< or = 2 cm) and 88 patients with larger breast carcinomas (2 to < 5 cm). All patients were free of distant metastasis. As tumor diameter increased, the frequency of oncogene amplification and LOH at all loci except D17S5 increased. However, there was no relationship between tumor diameter and amplification of specific oncogenes or allelic loss at specific loci. LOH at D17S5 was detected in 40% of small breast carcinomas (< or = 2 cm) and 43% of larger breast carcinomas (2 to < 5 cm). There was a significant correlation of LOH at D17S5 with INT2 amplification or with LOH on 11p, 16q, and 18q. These findings suggest that LOH at D17S5 may be involved in the early stage of breast carcinoma development, while INT2 amplification and LOH at 11p, 16q, and 18q appear to be genetic alterations that occur with tumor progression. In addition, as lymph node metastases were significantly related to amplification of the ERBB2 and MYC genes, and LOH of the NME1 gene, these genetic alterations may play a role in the mechanism of lymph node metastases.
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PMID:Analysis of genetic alterations related to the development and progression of breast carcinoma. 790 63

The etiology of breast cancer involves a complex interplay of various factors, including genetic alterations. Many studies have been devoted to the identification and characterization of mutations that occur frequently during breast tumorigenesis. The major types of genetic abnormalities that are frequently observed in breast tumors are amplification of protooncogenes (MYC, ERBB2) and DNA from chromosome band 11q13; mutation of TP53; and loss of heterozygosity from chromosomes and chromosome arms 1, 3p, 6q, 7q, 8p, 11, 13q, 16q, 17, 18q, and 22q. The latter may correspond to losses or inactivations of tumor suppressor genes. Recently, linkage analyses of large families with a predisposition to breast cancer have been performed in order to map breast cancer susceptibility genes (TP53, BRCA1, BRCA2). The findings have thrown light on the molecular mechanisms of breast cancer and have enabled various genetic markers to be used in clinical oncology.
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PMID:Genetic alterations in breast cancer. 860 12

Chronic myeloid leukaemia (CML) is characterized cytogenetically by a t(9;22)(q34;ql1) reciprocal translocation which gives origin to a hybrid BCR-ABL gene, encoding a p2lO(BCR-ABL) fusion protein with elevated tyrosine kinase activity and transforming abilities. The t(9;22) was suggested to be associated with genomic imprinting of centromeric regions of chromosomes 9 and 22, but the genes directly affected by the translocation, ABL and BCR, were shown not to be imprinted. For most diagnostic and research purposes the BCR-ABL gene can be efficiently identified by reverse-transcription and polymerase chain reaction (RT/PCR) amplification of its fusion transcripts, which can be quantified by competitive PCR and similar assays for assessment of residual disease in the follow-up of therapy. In the great majority of CML patients the BCR-ABL transcripts exhibit a b2a2 and/or a b3a2 junction; in rare cases, the only detectable BCR-ABL transcripts have unusual junctions, such as b2a3, b3a3, e1a2 or e6a2. There is a recent suggestion that the BCR-ABL gene may not be always 'functional', since extremely low levels of BCR-ABL transcripts can be found in leucocytes from normal individuals and, conversely, it appears that no BCR-ABL transcription can be detected in a proportion of Ph-positive haematopoietic progenitors from some CML patients. The role, if any, of the reciprocal ABL-BCR hybrid gene in CML is unknown. Although its mRNA message is in frame, no ABL-BCR fusion protein has yet been identified in CML patients. The blast crisis of CML has been variably associated with abnormalities of proto-oncogenes, such as RAS and MYC, or of tumour suppressor genes, in particular RB, p53 and p16, or with the generation of chimeric transcription factors, as in the AML1-EVI1 gene fusion. It is likely, therefore, that multiple and alternative molecular defects, as opposed to a single universal mechanism, underlie the acute transformation of the disease.
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PMID:The molecular biology of chronic myeloid leukaemia. 865 67


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