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)

In order to develop an effective therapeutic intervention for patients with pancreatic cancer, we analyzed the association of loss of heterozygosity (LOH) with the clinicopathological features of the disease. Based on these results, we are developing a new gene therapy that targets the genetic character of pancreatic cancer, using mutant adenoviruses that are selectively replication-competent in tumor cells. LOH of 30% or more was observed on chromosome arms 17p (47%), 9p (45%), 18q (43%), 12q (34%), and 6q (30%). LOH of 12q, 17p, and 18q showed significant association with poor prognosis. These data strongly suggest that mutations of the putative tumor suppressor genes, TP53 and SMAD4, play significant roles in the disease progression. Based on this rationale, we are developing a new gene therapy that targets tumors without normal TP53 function. The E1B-55kDa-deleted adenovirus can selectively replicate in TP53-deficient human tumor cells, but not in cells with functional TP53. We evaluated the therapeutic effect of this E1B-55kDa-deleted mutant adenovirus on pancreatic cancer without normal TP53 function. The growth of a human pancreatic tumor in a severe combined immunodeficiency (SCID) mouse model was markedly inhibited by consecutive injections of the E1B-55kDa-deleted adenovirus. Furthermore, the replication-competent adenovirus is not only a strong weapon itself but it is also a useful carrier of genes that possess antitumor activities, as a virus vector specific to tumors without normal TP53 function.
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PMID:Gene therapy for pancreatic cancer based on genetic characterization of the disease. 1202 95

Our understanding of the biology of pancreatic carcinoma has greatly benefited from studies of the genetic alterations in this tumor type. The p16-CDK4-cyclinD-Rb pathway, the p53 tumor suppressor pathway, and the DPC4/Smad4 pathway are genetically inactivated in the majority of sporadic pancreatic carcinomas, whereas oncogenic K-ras signaling is almost ubiquitously activated. These genetic data have provided the basis to shape a first genetic progression model of this tumor type. Furthermore, a number of well defined genetic syndromes which are associated with an inherited risk for pancreatic carcinoma have been identified recently.
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PMID:Molecular pathogenesis of pancreatic cancer. 1206 26

Because in the normal state, cells of the pancreas show a very low rate of proliferation, entering the cell cycle is assumed to be the initial event during tumorigenesis. So-called checkpoints monitor cell cycle progression and guarantee the proper duplication of the entire genome. Loss of one or more checkpoints causes subsequent accumulation of genetic alterations which finally results in cancer. Cancer cells are characterized by unrestricted growth, invasion of adjacent tissue and metastasis. All of these features can be explained in terms of genetic changes and the functional consequence of these changes. Activation of the proto-oncogene K-Ras and inactivation of the tumour suppressor gene loci INK4a, p53 and SMAD4 are characteristic for pancreatic cancer. The progression model of pancreatic cancer proposes that pancreatic intraepithelia neoplasia is the pre-cancerous lesion. A preferred genetic pathway has started to evolve. Germ-line mutations in specific genes are responsible for cases in which there is a familial predisposition to pancreatic cancer.
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PMID:Genetic basis of pancreatic cancer. 1207 67

Between January 1997 and February 2000, 101 fine-needle pancreatic aspirates were obtained. After a cytologic diagnosis was made, possible molecular alterations were determined on the 94 aspirates with adequate tissue using a molecular panel (K-ras, p53, and DPC4 [MAD4] genes). The 94 aspirates were categorized as follows: diagnostic of adenocarcinoma, 48 (51%); atypical (suggestive of but not diagnostic of adenocarcinoma), 19 (20%); negative for adenocarcinoma, 25 (2 7%); diagnostic of a neoplasm other than adenocarcinoma, 2 (2%). Clinical follow-up revealed that 3 patients (12%) with negative cytologic diagnoses and 12 patients (63%) with atypical cytologic diagnoses had adenocarcinoma. Of 63 with a final diagnosis of adenocarcinoma, 42 (67%) had an alteration in at least 1 of the genes analyzed. In contrast, only 2 (6%) of 31 patients without adenocarcinoma had an alteration in 1 gene on the panel. Overall, the molecular analyses supported the diagnosis of adenocarcinoma in 6 (32%) of 19 aspirates originally diagnosed as atypical by cytology alone. A molecular panel that includes the K-ras, p53, and DPC4 (MAD4) genes correlates with and can supplement traditional cytologic diagnosis of pancreatic fine-needle aspirates.
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PMID:K-ras, p53, and DPC4 (MAD4) alterations in fine-needle aspirates of the pancreas: a molecular panel correlates with and supplements cytologic diagnosis. 1209 Apr 25

Pancreatic cancer is an important cause of death from cancer throughout the world. Until recently, pancreatic cancer was a poorly understood disease. Research in the past decade has shown conclusively, however, that pancreatic cancer is primarily genetic in nature. Inactivation with a variety of tumor-suppressor genes such as p53, p16, and DPC4, and genome-maintenance genes such as BRCA2, coupled with the activation of oncogenes such as K-ras, are a few of the mutations that trigger the growth of cancerous cells. The genetic profile of pancreatic cancer has reshaped the nomenclature describing histological progression in pancreatic ductal tumorigenesis. K-ras mutations frequently occur early, whereas changes in the expression and genetic integrity of the p16 gene appear in intermediate lesions, and the inactivation of the p53 and DPC4 genes and activation of telomerase occur late in the neoplastic progression. Although the majority of pancreatic cancers occur sporadically, a minority has been shown to aggregate in families and has aided our understanding of pancreatic tumorigenesis. An improved understanding of the genetics of pancreatic cancer should lead to the development of gene-based screening tests and novel rational therapies.
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PMID:[Genetics of pancreatic cancer: recent advances in molecular diagnosis]. 1209 99

Human cell lines established from biliary tract cancers are rare, and only five have been reported previously. We report the characterisation of six new six biliary tract cancer cell lines (designated SNU-245, SNU-308, SNU-478, SNU-869, SNU-1079 and SNU-1196) established from primary tumour samples of Korean patients. The cell lines were isolated from two extrahepatic bile duct cancers (one adenocarcinoma of common bile duct, one hilar bile duct cancer), two adenocarcinomas of ampulla of Vater, one intrahepatic bile duct cancer (cholangiocarcinoma), and one adenocarcinoma of the gall bladder. The cell phenotypes, including the histopathology of the primary tumours and in vitro growth characteristics, were determined. We also performed molecular characterisation, including DNA fingerprinting analysis and abnormalities of K-ras, p15, p16, p53, hMLH1, hMSH2, DPC4, beta-catenin, E-cadherin, hOGG1, STK11, and TGF-betaRII genes by PCR-SSCP and sequencing analysis. In addition, we compared the genetic alterations in tumour cell lines and their corresponding tumour tissues. All lines grew as adherent cells. Population doubling times varied from 48-72 h. The culture success rate was 20% (six out of 30 attempts). All cell lines showed (i) relatively high viability; (ii) absence of mycoplasma or bacteria contamination; and (iii) genetic heterogeneity by DNA fingerprinting analysis. Among the lines, three lines had p53 mutations; and homozygous deletions in both p16 and p15 genes were found three and three lines, respectively; one line had a heterozygous missense mutation in hMLH1; E-cadherin gene was hypermethylated in two lines. Since the establishment of biliary tract cancer cell lines has been rarely reported in the literature, these newly established and well characterised biliary tract cancer cell lines would be very useful for studying the biology of biliary tract cancers, particularly those related to hypermethylation of E-cadherin gene in biliary tract cancer.
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PMID:Establishment and characterisation of six human biliary tract cancer cell lines. 1210 41

Pancreatic cancer is a devastating disease with a fatal prognosis due to late diagnosis and resistance to radiation and chemotherapy. The average survival after diagnosis is still 3 to 8 months. In the last few years genetic alterations in cancer-causing genes have been identified in tumors and putative premalignant lesions using microdissection techniques. However, the functional consequence of these genetic alterations for pancreatic growth and differentiation is unknown. TGF alpha overexpressed in the pancreas causes the development of tubular structures and fibrosis. Mice older than one year develop ductal pancreatic cancer. Crossbreeding these mice with p53 knockout mice dramatically accelerated tumor development. Moreover, tumors developing in these mice show frequently biallelic deletion of the Ink4a locus or LOH of SMAD4. These mice represent the first model of pancreatic adenocarcinomas with genetic alterations as well as growth characteristics similar to the human disease.
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PMID:TGF alpha transgenic mice. A model of pancreatic cancer development. 1212 Feb 15

In the present study, we used 22 microsatellite markers flanking to or within 13 known or candidate tumor suppressor genes (TSGs) to detect loss of heterozygosity (LOH) in these chromosomal regions among 41 cases of non-small cell lung cancer, including 28 squamous cell carcinoma (SCC) and 13 adenocarcinoma (ADC). The studied TSGs comprised FHIT, VHL, APC, PRLTS, p16, IFNA, PTEN, p57, ATM, p53, BRCA1, DPC4 and DCC. Our data demonstrated frequent allelic losses of FHIT, p53, IFNA, VHL and p16 in both SCC and ADC. PTEN and ATM showed the least frequency of LOH, while no deletion of BRCA1 was detected in all tumor samples. LOH analysis of PRLTS was extended to 26 cases of ADC, which demonstrated significantly higher frequency of LOH than SCC. Our data indicated a possible correlation between specific TSG(s) and either histological type of lung cancer, and more attention should be paid to the PRLTS gene, which might play an important role in the development of ADC.
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PMID:Deletion of tumor suppressor genes in Chinese non-small cell lung cancer. 1212 91

A case of intraductal oncocytic papillary neoplasm of the pancreas, with the rare progression to invasive carcinoma, is described. The intraductal oncocytic papillary neoplasm component had the features typical of this entity, with stratified layers of oncocytic cuboidal tumor cells growing in papillary and pseudopapillary arrangements within dilated pancreatic ducts. The invasive carcinoma formed a discrete fleshy tumor with well-circumscribed borders. The invasive carcinoma grew in solid lobules, subdivided by fine fibrovascular septae into predominantly organoid and trabecular growth patterns. Molecular analysis showed no loss of heterozygosity for microsatellite markers at the tumor suppressor loci of TP53, CDKN2A (p16/INK4A), and MADH4 (Smad4/DPC4) in the invasive carcinoma, although loss of heterozygosity was detected at one CDKN2A marker in the intraductal component. DNA sequencing of polymerase chain reaction amplification products of exons 1 and 2 of the CDKN2A gene showed no mutation in either tumor component. TP53 immunohistochemistry showed no increased levels of staining, consistent with the presence of wild-type gene product. Polymerase chain reaction and DNA sequencing showed no mutation of codons 12 and 13 of the KRAS proto-oncogene. These results suggest that intraductal oncocytic papillary neoplasm is a neoplasm with genetic changes that are distinct from typical pancreatic adenocarcinoma. The lack of mutation in these genes may be an explanation for the typically indolent clinical behavior of intraductal oncocytic papillary neoplasms.
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PMID:Genetic analysis of invasive carcinoma arising in intraductal oncocytic papillary neoplasm of the pancreas. 1217 96

Gastric cancer of youth is predominantly a disease of women, usually of the signet-ring cell subtype, with a predilection for metastasizing to the ovaries. The metastatic ovarian tumor is named a Krukenberg tumor. However, the characteristic genetic alterations between the primary gastric cancer and its metastatic ovarian tumor have not been studied. We used laser capture microdissection to procure tissues from 7 patients with gastric cancer who had ovarian metastases (Krukenberg tumor) and tissues from 14 patients with gastric cancer without ovarian metastases. Loss of heterozygosity (LOH) analysis was performed by use of 16 polymorphic markers, which are mapped to the FHIT, APC, p16, BRCA2, E-cadherin, p53, BRCA1, and DPC4 loci. Immunohistochemical staining with anti-Fhit antibody was performed in 7 Krukenberg tumors and 92 gastric cancers without ovarian metastases. LOH at the FHIT locus was observed in six (85.7%) of the seven Krukenberg tumors. In contrast, the gastric cancers without ovarian metastases showed a lower frequency (28.6%, 4/14) of LOH at the FHIT locus (p < 0.05, odds ratio = 1/15). Anti-Fhit antibody showed that expression of Fhit was lost in each of the 7 (100%) Krukenberg tumors but in only 41 (44.6%) of the 92 patients who had gastric cancer without ovarian metastases (p < 0.05; odds ratio = 1/18.614). Further analysis showed that loss of Fhit expression is highly associated with signet-ring cell type gastric cancer (p < 0.0001, odds ratio = 62.5) but is not correlated with prognosis. Alteration of the FHIT gene is a characteristic of signet-ring cell type gastric cancer and Krukenberg tumor.
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PMID:Preferential loss of Fhit expression in signet-ring cell and Krukenberg subtypes of gastric cancer. 1221 81


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