Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DUSP6/MKP-3 is identified as a candidate tumor suppressor gene for pancreatic cancer. The aim of this study was to elucidate the roles of DUSP6 in the pancreatic carcinogenesis through the pancreatic intraepithelial neoplasia and/or intraductal papillary-mucinous neoplasms, both of which are considered to be precursor lesions of invasive carcinoma of the pancreas, by comparing with involvements of other major tumor suppressive pathways. Expressions of DUSP6, CDKN2A, TP53, and SMAD4 were investigated by immunohistochemistry in a total of 206 lesions of dysplastic ductal precursors and carcinomas retrieved from 52 pancreata with invasive ductal carcinomas and 51 of those with intraductal papillary-mucinous neoplasms. The intensity of staining was evaluated in lesions at different atypical grades and statistically compared among them. Mutations of KRAS2 were analyzed by methods of the allele-specific oligonucleotide hybridization and nucleotide sequencing. In pancreata with invasive ductal carcinomas, expressions of DUSP6 were abrogated exclusively in the invasive carcinoma cells in contrast to its fairly preserved expressions in pancreatic intraepithelial neoplasia. In pancreata with intraductal papillary-mucinous neoplasms, abrogated expressions of DUSP6 were observed in a relatively small fraction of intraductal adenoma/borderlines and intraductal carcinomas. Most of the intraductal adenoma/borderline lesions with abrogation of DUSP6 harbored mutations of KRAS2. None of the molecules was associated with each other in any grade of lesions. Morphological variations of papillae of the intraductal papillary-mucinous neoplasms were evaluated and analyzed for their associations with abrogations of the molecules, which resulted in finding of no significant associations. Our results suggest that the abrogation of DUSP6 is associated exclusively with progression from pancreatic intraepithelial neoplasia to the invasive ductal carcinoma while it is potentially associated with initiation of intraductal papillary-mucinous neoplasms with mutated KRAS2, which is independent of other major tumor suppressive pathways in both types of neoplasms.
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PMID:Distinct progression pathways involving the dysfunction of DUSP6/MKP-3 in pancreatic intraepithelial neoplasia and intraductal papillary-mucinous neoplasms of the pancreas. 1583 94

The virtual lack of well-characterized metastatic pancreatic cancer tissues for study has limited systematic studies of the metastatic process of this deadly disease. To address this important issue, we have instituted a rapid autopsy protocol for the collection of high quality tissues from patients with metastatic pancreatic cancer, called the Gastrointestinal Cancer Rapid Medical Donation Program (GICRMDP). At the time of preparation of this manuscript, 20 patients with metastatic pancreatic cancer and one patient with metastatic colon cancer have undergone a rapid autopsy in association with the GICRMDP. The average time interval achieved for these 21 patients was 8.0 hours, with more than 500 individual samples of matched high quality primary and metastatic pancreatic cancer tissues, peritoneal/pleural fluid and blood obtained so far. For the first four patients in which the autopsy was performed in <6 hours, we have successfully xenografted the primary tumor and/or two to four independent matched metastases from a variety of target organ sites, with a take rate of almost 60% for the first 26 xenografted tumors attempted. In an initial survey of KRAS2, TP53 and DPC4 genetic status in lethal metastatic pancreatic cancers, activating KRAS2 mutations were detected in 82% of cases and inactivating TP53 mutations in 55% of cases, consistent with rates of genetic alteration of these genes in early stage pancreatic cancers. However, DPC4 inactivation was found in 75% of patients analyzed, suggesting that genetic inactivation of the DPC4 tumor suppressor gene continues to be selected for with growth at the primary site and metastatic spread to other organs. The invaluable tissue resources generated by the success of the GICRMDP will provide an unparalleled resource for study of metastatic pancreatic cancer and of the metastatic process in general.
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PMID:Immortalizing the complexity of cancer metastasis: genetic features of lethal metastatic pancreatic cancer obtained from rapid autopsy. 1584 69

Here we report the complex pattern of genomic imbalances and rearrangements in a panel of 19 renal cell carcinoma cell lines detected with molecular cytogenetic analysis. Consistent heterogeneity in chromosome number was found, and most cell lines showed a near-triploid chromosome complement. Several cell lines showed deletions of the TP53 (alias p53), CDKN2A (alias p16), and VHL genes. Multiplex fluorescence in situ hybridization (M-FISH) analysis revealed chromosome 3 translocated to several other partners chromosomes, as well as breakage events commonly affecting chromosomes 1, 5, 8, 10, and 17. The most common abnormality detected with comparative genomic hybridization (CGH) was deletions of chromosome 3p, with loss of the RASSF1, FHIT, and p44S10 loci frequently involved. CGH gain of 5q showed overrepresentation of the EGR1 and CSF1R genes. Recurrent alterations to chromosome 7 included rearrangement of 7q11 and gains of the EGFR, TIF1, and RFC2 genes. Several lines exhibited rearrangement of 12q11 approximately q14 and overrepresentation of CDK4 and SAS loci. M-FISH revealed several other recurrent translocations, and CGH findings included loss of 9p, 14q, and 18q and gain of 8q, 12, and 20. Further genomic microarray changes included loss of MTAP, IGH@, HTR1B, and SMAD4 (previously MADH4) and gains of MYC and TOP1. An excellent correlation was observed between the genomic array and FISH data, demonstrating that this technique is effective and accurate. The aberrations detected here may reflect important pathways in renal cancer pathogenesis.
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PMID:A combination of molecular cytogenetic analyses reveals complex genetic alterations in conventional renal cell carcinoma. 1586 Mar 50

Genomic alterations influencing the expression and/or activity of tumor suppressors or oncogenes such as KRAS2, CDKN2A, TP53, and DPC4 have been directly implicated in the initiation and progression of human pancreatic adenocarcinoma. In an effort further to systematically characterize the genomic alterations that occur in this disease, we conducted a genome wide analysis of alterations in gene copy number using array-based comparative genomic hybridization (CGH). For this analysis, we utilized a panel of 25 human pancreatic cancer cell lines derived from either primary or metastatic tumors. This panel also included a metastatic progression series of cell lines derived from COLO 357 cells. Array CGH permitted the identification of alterations in the copy number of genes that might participate in the aberrant behavior of pancreatic cancer cells. In addition, the acquisition of invasive and metastatic potential by derivatives of COLO 357 cells was accompanied by additional focal genomic alterations including point mutations and amplification of KRAS2. To complement the array CGH analysis, we also conducted an analysis of mRNA expression patterns in a subset of these cells using cDNA microarrays. By this means, we identified a set of candidate genes, including those regulated by RAS signaling, that may contribute to the process of cancer cell invasion and metastasis. Supplementary material for this article can be found on the Genes, Chromosomes, and Cancer website at http://www.interscience.wiley.com/jpages/1045-2257/suppmat/index.html.
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PMID:Analysis of genomic DNA alterations and mRNA expression patterns in a panel of human pancreatic cancer cell lines. 1592 91

Barrett's esophagus (BE) is a major predisposing factor for the development of esophageal adenocarcinoma. Current strategies for treatment of BE, both dysplastic and nondysplastic, include photodynamic therapy (PDT) and argon plasma coagulation (APC). However, the effect of ablative therapy at the genetic level is unclear. We performed loss of heterozygosity (LOH) analysis of BE in baseline and follow-up biopsy specimens from 21 patients with BE (17 male, 4 female) treated with PDT and/or APC. At baseline, 14 patients had intestinal metaplasia without dysplasia (MET), 4 low-grade dysplasia (LGD) and 3 high-grade dysplasia (HGD). LOH was assessed using a panel of 9 polymorphic markers for evaluation of the P53 gene on 17p, P16 on 9p, DCC and SMAD4 on 18q and the APC gene on 5q. The tissue specimens obtained at baseline (t = 0) were analysed, as well as the first (t = 1; mean interval: 4 months) and last (t = 2; mean interval: 8 months) available biopsy with residual or recurrent BE after ablation. At t = 0, allelic loss was detected of 5q in 27%, 9p in 56%, 17p in 31% and 18q in 6% of informative cases. At t = 1 (18 patients with persistent MET and 3 with LGD) and at t = 2 (8 MET, 2 LGD), the LOH patterns were not statistically different from t = 0. Further, multiple genetic lineages before and after therapy were detected in 15 cases illustrating the multiclonal nature of BE. We conclude that recurrent and/or persistent BE after ablative therapy still contains genetic alterations associated with malignant progression to cancer. Therefore, the goal of treatment should be the complete elimination of Barrett's mucosa.
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PMID:Genomic analysis of Barrett's esophagus after ablative therapy: persistence of genetic alterations at tumor suppressor loci. 1603 7

Pancreatic cancer is one of the most lethal tumours of the gastrointestinal tract. The ability to predict which patients would benefit most from surgical intervention and/or chemotherapy would be a great clinical asset. Considerable research has focused on identifying molecular events in pancreatic carcinogenesis, and their correlation with clinicopathological variables of pancreatic tumours and survival. This systematic review examined evidence from published manuscripts looking at molecular markers in pancreatic cancer and their correlation with tumour stage and grade, response to chemotherapy and long-term survival. A literature search was undertaken using PubMed and MEDLINE search engines, using the keywords p53, p21, p16, p27, SMAD4, K-ras, cyclin D1, Bax, Bcl-2, EGFR, EGF, c-erbB2, HB-EGF, TGFbeta, FGF, MMP, uPA, cathepsin, heparanase, E-cadherin, laminins, integrins, TMSF, CD44, cytokines, angiogenesis, VEGF, IL-8, beta-catenin, DNA microarray, and gene profiling. A bewildering number of biomarkers are currently under evaluation. For the most part, the evidence regarding their application as prognostic indicators is conflicting. The advent of gene microarray and mass spectrometric protein profiling offers the potential to examine many different biomarkers simultaneously. This 'protein/gene signature' could revolutionise work in this field and allow researchers to develop accurate and reproducible predictions of survival based on protein or gene profiles.
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PMID:Molecular prognostic markers in pancreatic cancer: a systematic review. 1614 90

This review describes: 1. The main genetic alterations found in pancreatic cancer (EGF-R overexpression, SST-2 somatostatin receptor loss of expression, k-ras, p53 mutations and DPC4 mutations) and the effect of their replacements by gene therapy on tumor growth; 2. The use of suicide genes (HSV-TK and CD) for pancreatic cancer gene therapy in vitro and in vivo; 3. The implications for pancreatic cancer treatment when using cytotoxic bacterial toxins; 4. Viral and non-viral delivery systems for the transfer of therapeutical genes into pancreatic cancer cells. Overall both the correction of pancreatic cancer cells main genetic alterations and the use of suicide genes allow only partial tumor regression in vitro and in vivo. The lack of a 100% effect for any studied strategy considered alone, indicates the need for combined therapies to achieve a satisfactory treatment of this tumor.
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PMID:Killer genes in pancreatic cancer therapy. 1617 65

Most pancreatic neoplasia are of ductal lineage, characterized by tubule (gland), cyst, papilla, or mucin formation and expression of mucin-related glycoproteins and oncoproteins (eg, MUC1, CA19-9, CEA, DUPAN), as well as some subsets of cytokeratin (eg, CK19). Mutations of k-ras oncogene and DPC4 are also common in ductal neoplasia and generally not seen in nonductal tumors. A variety of pancreatic neoplasia fall under the heading of ductal neoplasia. Invasive ductal adenocarcinoma (DA) is the most important and constitutes the vast majority (>85%) of pancreatic tumors. DA is characterized by insidious infiltration and rapid dissemination, despite its relatively well-differentiated histologic appearance. In some variants of DA such as undifferentiated or sarcomatoid, evidence of ductal differentiation may be lacking or only focal. The presumed precursors of DA are microscopic intraductal proliferative changes that are now termed pancreatic intraepithelial neoplasia (PanIN). PanINs comprise a neoplastic transformation ranging from early mucinous change (PanIN-1A) to frank CIS (PanIN-3). A similar (in situ) neoplastic spectrum also characterizes intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, which are cystic ductal-mucinous tumors with varying degrees of papilla formation, and may be associated with invasive carcinoma. As such, these can be regarded as mass-forming preinvasive neoplasia. Some intraductal papillary mucinous neoplasms are associated with invasive carcinoma of the colloid type. Colloid carcinoma of the pancreas appears to be a clinicopathologically distinct tumor with indolent behavior. Whereas most ductal pancreatic neoplasia are characterized by some degree of mucin formation, serous tumors, of which serous (microcystic) adenoma is the sole example, lack mucin formation, presumably because they recapitulate centroacinar ducts. They are typically benign tumors. It is recognized now that pancreatic carcinoma, like other malignant processes, is a genetic disease produced by progressive mutations in cancer-related genes. These alterations can be categorized as "early" such as k-ras mutation, HER-2/neu, PSCA, MUC5, and fascin overexpression; "intermediate" such as p16 inactivation, MUC1, and cyclin D1 overexpression; and finally as "late" such as p53 and DPC4 inactivation, BRCA2 mutation, and overexpression of ki-67, 14-3-3sigma, and mesothelin. Ductal neoplasia is the most important category among pancreatic tumors. It is important to appreciate the different types of ductal tumors because they vary greatly in their clinicopathologic characteristics and prognosis. Understanding the molecular mechanisms of ductal carcinogenesis will help develop more efficient prevention and therapy of these tumors.
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PMID:Ductal neoplasia of the pancreas: nosologic, clinicopathologic, and biologic aspects. 1618 79

Pancreatic ductal adenocarcinoma is one of the most fatal malignancies. Intensive investigation of molecular pathogenesis might lead to identifying useful molecules for diagnosis and treatment of the disease. Pancreatic ductal adenocarcinoma harbors complicated aberrations of alleles including losses of 1p, 6q, 9p, 12q, 17p, 18q, and 21q, and gains of 8q and 20q. Pancreatic cancer is usually initiated by mutation of KRAS and aberrant expression of SHH. Overexpression of AURKA mapping on 20q13.2 may significantly enhance overt tumorigenesity. Aberrations of tumor suppressor genes synergistically accelerate progression of the carcinogenic pathway through pancreatic intraepithelial neoplasia (PanIN) to invasive ductal adenocarcinoma. Abrogation of CDKN2A occurs in low-grade/early PanIN, whereas aberrations of TP53 and SMAD4 occur in high-grade/late PanIN. SMAD4 may play suppressive roles in tumorigenesis by inhibition of angiogenesis. Loss of 18q precedes SMAD4 inactivation, and restoration of chromosome 18 in pancreatic cancer cells results in tumor suppressive phenotypes regardless of SMAD4 status, indicating the possible existence of a tumor suppressor gene(s) other than SMAD4 on 18q. DUSP6 at 12q21-q22 is frequently abrogated by loss of expression in invasive ductal adenocarcinomas despite fairly preserved expression in PanIN, which suggests that DUSP6 works as a tumor suppressor in pancreatic carcinogenesis. Restoration of chromosome 12 also suppresses growths of pancreatic cancer cells despite the recovery of expression of DUSP6; the existence of yet another tumor suppressor gene on 12q is strongly suggested. Understanding the molecular mechanisms of pancreatic carcinogenesis will likely provide novel clues for preventing, detecting, and ultimately curing this life-threatening disease.
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PMID:Molecular mechanisms of pancreatic carcinogenesis. 1636 14

Pancreatic cancer is fundamentally a disease of inherited and acquired mutations in cancer-related genes. The genes targeted in pancreatic cancer include tumor-suppressor genes (p16/CDKN2A, TP53 and SMAD4), oncogenes (KRAS, BRAF, AKT2, MYB, and AIB1), and genome-maintenance genes (MLH1, MSH2, BRAC2 and other Fanconi anemia genes). An understanding of the cancer-related genes that are altered in pancreatic cancer has a number of clinical applications including genetic counseling for individuals with a family history of cancer, early detection of pancreatic neoplasia, and mechanism-based therapies for patients with advanced disease. This chapter will provide an overview of the molecular pathogenesis of pancreatic cancer with emphasis on clinical applications.
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PMID:Molecular pathogenesis of pancreatic cancer. 1654 25


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