Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently p73, a novel p53 homologous tumour suppressor gene, has been cloned and mapped to chromosome 1p36. Like p53, important functions of p73 in controlling the cell cycle and programmed cell death have been described. Loss of p73 has been demonstrated in neuroblastomas and its involvement in tumorigenesis has been suggested to occur in other neuroectodermal cancers. Since genetic alterations at the tumour suppressor locus 1p36 have been also identified in malignant melanomas, we investigated the expression of p73 in a panel of nine different human melanoma cell lines, 17 melanocytic naevi, 17 primary malignant melanomas and 20 metastases by reverse transcriptase polymerase chain reaction (PCR) and Southern blotting. We observed significant p73 mRNA expression in all the cell lines and tissue specimens except one benign melanocytic naevus and one melanoma metastasis. Sequencing the PCR fragments of nine melanoma cell lines derived from primary tumours and five metastases over the entire p73 DNA binding domain revealed wild-type sequences in all cases. In summary, we conclude that loss of p73 mRNA expression or mutations in the p73 DNA binding domain do not represent common genetic events involved in the pathogenesis of malignant melanomas.
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PMID:Loss of expression or mutations in the p73 tumour suppressor gene are not involved in the pathogenesis of malignant melanomas. 991 12

The p73 gene encodes a protein that shares structural and functional homologies with the p53 tumor suppressor protein. The p73 gene is monoallelically expressed in normal tissue, maps to chromosome 1p36 and is deleted in human neuroblastoma cell lines. Alternative splicing of exon 13 in p73 transcripts generates two isoforms, p73alpha and p73beta, that differ in their carboxy-terminus and in their ability to form homotypic interactions. In this study, we investigated, in 129 human central nervous system tumors of various histological types, the levels of p73 transcripts and the splicing characteristics of p73 mRNA. Whereas p73 mRNA content was consistently low in most tumoral types, especially in meningiomas, some glioblastomas, medulloblastomas and metastases exhibited elevated p73 mRNA content. However, ependymomas expressed consistently high amounts of p73 mRNA, significantly different from the other tumoral types. Whereas the short (p73beta) isoform accounted for 20-25% of the total p73 mRNA in most of the tumors, these splicing characteristics were altered in ependymomas (only 9% of p73beta) and in neurinomas (up to 53% of p73beta). These observations suggest tissular or tumoral differences in the control of p73 gene transcription and alternative splicing, and raise the problem of the role of p73 isoforms in the control of tumor growth, particularly in ependymomas.
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PMID:p73 gene transcripts in human brain tumors: overexpression and altered splicing in ependymomas. 1021 63

A novel gene, termed p73 with significant homology to p53, has been identified at 1p36, a chromosomal region which is frequently deleted in malignant melanoma. To determine whether p73 is involved in melanoma development we analyzed 8 benign melanocytic nevi, 17 primary melanomas, 34 melanoma metastases and 9 melanoma cell lines for p73 alterations. Allelic loss at the p73 locus was observed in 2 of 10 cases (20%) and occurred only in metastatic tumors. Mutation analysis of the DNA-binding domain of p73 revealed no somatic mutations in the tumor specimens and melanoma cell lines analyzed, whereas the p53 gene was mutated in 5 of 9 melanoma cell lines. Expression analysis of p73 using semiquantitative RT-PCR demonstrated that p73 is not expressed or at exceedingly low levels in benign melanocytic nevi, primary melanomas and lymph node metastases, but at various levels in melanoma cell lines. Our data indicate that p73 does not play a role as a tumor suppressor in melanoma development.
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PMID:Lack of p73 mutations and late occurrence of p73 allelic deletions in melanoma tissues and cell lines. 1040 74

p73, a new member of the p53 family, has been mapped to chromosome 1p 36, a region where loss of heterozygosity (LOH) is frequently observed in primary human tumors. Allelic loss studies involving the 1p arm in breast carcinomas offer rates ranging from 13% to 75%, depending on the genetic interval being studied. We investigated LOH in an intragenic microsatellite marker, and those centromerically flanking the p73 gene, at 1p 36, and their correlations with patient age and 10 pathologic parameters in a series of 193 breast carcinomas. The LOH analysis was performed by amplifying DNA by PCR, using the five markers of the 1p 36 region (p73P1, D1S2694, D1S214, D1S2666 and D1S450). LOH was found in at least one of these markers in 27% of tumors. When we established the comparison between tumors with and without LOH and the distribution of the 10 pathologic parameters considered, we observed statistically significant differences in association with higher histologic grade (p = 0.02), more advanced pathological stage (p = 0.02), peritumoral vessel involvement (p = 0.04) and poorly differentiated carcinomas (p = 0.01), as well as in tumors that concomitantly exhibited lymph node metastases, peritumoral vessel involvement and absence of steroid receptors (p = 0.02). These data suggest that LOH in the p73 region could be pathogenically related to breast cancer and possibly to a poor tumor prognosis.
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PMID:Clinicopathological characteristics of breast carcinomas with allelic loss in the p73 region. 1107 55

p27 is a cyclin-dependent kinase inhibitor which regulates progression of cells from G1 into S phase in a cell cycle. Loss of the negative regulator may contribute to oncogenesis and tumor progression. The aim of this study was to examine p27 expression in normal mucosa, primary and metastatic tumors from patients with colorectal adenocarcinomas and to analyze association of p27 with patient survival and clinicopathological variables. p27 expression was estimated by immunohistochemistry in 178 primary colorectal cancers, 34 lymph node metastases and 48 normal mucosa samples from patients with colorectal adenocarcinoma. Associations of p27 with patient survival, clinicopathological characteristics and expression of p53, p73 and DCC were analyzed. Loss of p27 was found in 51% of primary tumors, 68% of metastases and 56% of normal samples. The intensity of p27 staining was similar in the matched primary tumor, metastasis and normal mucosa. In patients with Dukes' B or with proximal tumors, the loss of p27 predicted poorer prognosis (p = 0.03 and p = 0.05, respectively). However, there were no significant differences in the patients with other individual Dukes' stage or distal tumors. No relationships were found between p27 and patients' gender, age, tumor location, growth pattern and expression of p53, p73 and DCC (p > 0.05). The data suggest that loss of p27 was associated with poor prognosis in patients with Dukes' B tumor or those with proximal tumor. p27 might be a useful marker to identify the more progressive tumors in these groups.
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PMID:Loss of p27 expression predicts poor prognosis in patients with Dukes' B stage or proximal colorectal cancer. 1140 21

Metastasis and invasion are key steps in the systemic spread of tumor cells. To identify the genes involved in this process we recently selected highly invasive and weakly invasive cell clones from a melanoma cell line. Both cell clones showed a stable phenotype over more than 40 passages and previous analyses revealed a fivefold difference in their invasive potential in vitro and in tumorigenesis in vivo. To compare gene expression of the two cell clones a cDNA array system (Clontech human cancer cDNA array) was used. Exact quantification of differentially expressed genes in each cell clone was performed by real-time RT-PCR. An evaluation of the array data revealed a total of 36 genes that were more than 1.5-fold differentially expressed, and 26 (72%) of these showed a differential expression pattern by quantitative RT-PCR. Previously known differences in expression patterns, including loss of p16 and HLA I, or equal expression of p73, and RAR alpha, beta and gamma were confirmed by the array data. In addition, reduced expression levels of several cytoskeletal proteins, such as vimentin, gamma-actin, desmin and cytokeratins, in the highly invasive cell clone were reproducibly identified. Other genes strongly upregulated in the highly invasive cell clone included jagged 2, STAT1, tPA and c-myc, whereas MDA-6 (p21), caspase 2 and semaphorin were found to be downregulated. In conclusion, comparative hybridization of cDNA arrays identified a series of novel invasion-associated changes in gene expression and confirmed previously known expression patterns.
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PMID:Isolation of invasion-associated cDNAs in melanoma. 1148 May 87

The overexpression of wild type p73 is the most frequent alteration of p73 in malignancies. We investigated, in 70 breast carcinomas, p73 mRNA expression and its relationship to p53 mutations, determined by an immunohistochemical method, and loss heterozygosity (LOH) status of the 1p36 region, together with its possible implication in the pathogenesis of breast carcinomas. LOH, amplifying DNA by PCR using 5 markers, of 1p36 region (one intragenic to p73 gene) was found in 17% of cases but no significant correlation was observed with p73 overexpression. p53 positive immunostaining was present in 33% of breast carcinomas, and these exhibited a statistically significant relation with p73 overexpressed tumors. Overexpression of p73 mRNA was observed in 19 tumors (27%). The analysis of cases with p73 overexpression and cases with normal mRNA expression, in terms of age and pathologic characteristics of the tumors showed a significant association of p73 overexpression and tumors with lymph node metastases, vascular invasion and higher pathologic stage. These results suggest that p73 overexpression is a molecular alteration that could be implicated in the tumorigenesis of breast carcinomas and, eventually, in a poor clinical behavior.
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PMID:Wild type p73 overexpression and high-grade malignancy in breast cancer. 1151 Jun 89

Several genetic alterations have been implicated in the development of malignant melanoma, but the expression of oncogenes, tumour suppressor, mismatch repair and apoptosis-related genes and their interactions in melanoma have not been completely clarified. We simultaneously examined the expression of p73, c-erbB-2, ras, p53, Mdm2, p27, DCC, hMLH-1, hMSH-2, bcl-2, Bax and NF-kappaB, by immunocytochemistry, in both primary and metastatic melanoma cell lines derived from melanoma patients. p73 was expressed in 7/8 cell lines, but stronger expressed in the metastatic cells than in the primary melanoma cells. c-erbB-2 was detected in all 8 cell lines and ras in 2/5 metastases. p53 was found in all the cell lines and Mdm2 in 1/8 of the cell lines. In the same patient, the intensity of p27 expression was decreased from the primary to the metastatic tumours. bcl-2 was expressed in all the cell lines. Bax was absent in 5/8 cell lines. In the same patient, Bax was weakly expressed in the primary tumour but lacking in the metastases. The data demonstrate that overexpression of p73, c-erbB-2, p53 and bcl-2, and loss of Mdm2 and Bax may interact and play important roles in the development and aggressiveness of human melanoma.
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PMID:Expression of oncogenes, tumour suppressor, mismatch repair and apoptosis-related genes in primary and metastatic melanoma cells. 1171 83

The common clinical problem in the successful treatment of cancer is the resistance of cancer cells to chemotherapeutic drugs. Chemotherapy kills drug-sensitive cells, but leaves behind a higher proportion of drug-resistant cells. The resistance can be due to altered drug accumulation, retention, metabolism and distribution, or to reduced drug-target interaction. More recently, cell cycle progression, DNA mismatch repair (MMR) and cell death have been shown to play an important role in the regulation of cell resistance to anticancer drugs. Chkl regulation pathways, DNA MMR and p73, as well as altered apoptotic cell death involved in the cell resistance toward DNA damaging agents will be reviewed in this article.
Cancer Metastasis Rev 2001
PMID:Targeting molecular signals in chk1 pathways as a new approach for overcoming drug resistance. 1183 38

In the last 2 years, it has become apparent that the p53-family members p53 and p73 play fundamentally different roles in human malignancies. In contrast to p53, many studies on cancer patients failed to detect mutational inactivation of p73 and reported overexpression of wild-type p73 instead. A possible explanation was provided by the recent discovery of N-terminal truncated isoforms of p73 (DeltaTA-p73) that act as dominant-negative inhibitors of wild-type p53 and TA-p73 and result in tumor growth in nude mice. We investigated the role of DeltaTA-p73 in the development and progression of human melanomas, which lack p53 mutations. We analyzed 8 benign melanocytic nevi, 8 primary melanomas and 19 melanoma metastases for alterations of TA-p73 and DeltaTA-p73 expression using isoform-specific real-time RT-PCR. Based on our results, p73Deltaex2 and Deltaex2/3 spliced transcripts derived from the first promoter were significantly up-regulated in melanoma metastases, whereas DeltaN-p73 generated from the second promoter was the predominant isoform in benign nevi. Moreover, increased expression of p73Deltaex2 and p73Deltaex2/3 correlated with high-levels of both TA-p73 and E2F1. Our data suggest a potential function of DeltaTA-p73 splice isoforms in melanoma progression.
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PMID:Alterations of DeltaTA-p 73 splice transcripts during melanoma development and progression. 1461 32


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