Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0178874 (tumor progression)
40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blood normal and tumor tissue samples of 23 patients with sporadic colorectal tumors were screened for DNA alterations in the tumor relevant genes APC, K-ras, DCC and p53. Six different microsatellite regions were analyzed for instability by a new developed non-radioactive method. Somatic DNA alterations were found in 17 tumor samples: 13 carried single or multiple changes in single genes; six carried alterations in microsatellites; two tumors showed tumor suppressor gene mutations in addition to microsatellite changes. We found no indications of correlations between current genetic models of colorectal tumor progression and the established TNM system for histopathological tumor classification.
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PMID:DNA alterations in sporadic colorectal tumors do not correlate with tumor staging diagnosed by the TNM system. 902 Sep 16

Tumor behavior is the result of specific genetic changes that alter gene expression. From our cytogenetic studies chromosome 18 loss emerged as a common genetic change in squamous carcinoma cell lines. In this report we summarize data that link loss of 18 to tumor progression and reduced survival, indicating that one or more tumor suppressor gene(s) are located on this chromosome. Tumors grown in vitro were karyotyped either as short-term or permanent cultures. Loss of chromosome 18 was measured by karyotype, decreased frequency of heterozygosity at the DCC locus, and loss of heterozygosity (LOH) for microsatellite repeat polymorphisms (MSRP). Loss of any part of chromosome 18 was observed in approximately 63% of cultured tumors. Primary and secondary tumors from the same individuals sometimes differed in loss of 18 indicating that this genetic change is associated with tumor progression. Heterozygosity for DCC was present in only 3/19 cultured SCC (16%), compared with 68% (11/16) of blood samples from unrelated donors, which is consistent with LOH in roughly one half of the cases. Of 4 informative cases with normal and tumor tissue, LOH was observed in 2. Microsatellite analysis also shows loss of 18q in 55% of fresh tumors. Analysis of tumor tissue and cell lines from the same patient gave identical results. There was an excess of deaths from cancer in the group with 18 loss (20/25) when compared with the group without (5/15). Loss of chromosome 18 appears to be a marker of tumor progression in SCC. It is likely that mutation affecting DCC or another gene on 18 affects tumor growth or spread, leading to more rapid progression and reduced survival.
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PMID:Identifying genetic changes associated with tumor progression in squamous cell carcinoma. 928 18

Microsatellite instability (MSI) is intrinsic to most colorectal carcinomas (CRC) from patients with hereditary nonpolyposis colorectal cancer (HNPCC), reflecting germline mutations in the mismatch-repair (MMR) genes. Its occurrence and chronological sequence of development in sporadic CRC appears less well defined. To explore the time sequence in acquisition of MSI, and the role it plays during tumor progression in sporadic CRC, we compared the incidence of MSI in tissue samples from 40 Dukes'-B and 30 Dukes'-D CRC patients with liver metastases, at 4 different microsatellite loci, representing sites on the APC, DCC and p53 genes respectively as well as the D2S123 site. Among the 30 patients with hepatic metastases, MSI was found in 9 (30%) of the primary, and 13 (43.3%) of the metastatic tumors. In comparison, among the 40 Dukes'-B CRC, MSI was found in only 8 cases (20%). CRC with MSI were more frequently located in the right colon, less frequently on the left side, and seldom in the rectum. Tumor ploidy analysis shows that 46.2% of Dukes'-D primary tumors with MSI are diploid (chi2 = 4.46, p = 0.035). With a mean follow-up time of 4.2 years for the Dukes'-B CRC, there were no recurrences in the 8 patients with MSI, whilst 6 (18.8%) relapses occurred amongst the 32 patients without MSI, average time to recurrence being 15 months. In Dukes'-D CRC, mean survival time for patients with MSI was 37 months (95% CI, 24 to 51 months), for those without MSI 26 months (95% CI, 18 to 35 months), although this was not statistically significant. Our data suggest that tumor progression may involve increased genetic instability.
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PMID:Microsatellite instability in sporadic-colon-cancer patients with and without liver metastases. 929 42

Recent studies have identified the distinct existence of flat-type colorectal tumors. The low incidence of ras gene mutations in these tumors suggests that their genetic pathways of tumor progression may be different from those of the polypoid type. To elucidate further genetic alterations in flat-type colorectal tumors, codon 201Arg/Gly polymorphism in the DCC (deleted in colorectal carcinoma) gene was analyzed in normal tissue (normal colonic mucosa or peripheral lymphocytes) and in tumor tissue from 191 patients with colorectal tumors (36 patients with flat-type colorectal tumors, 81 patients with polypoid-type colorectal tumors, and 74 patients with advanced carcinomas). For normal controls, 30 samples obtained from patients who had neither colorectal tumors (confirmed by total colonoscopy) nor a family history of colorectal carcinoma were analyzed. DCC gene codon 201Arg/Gly polymorphism was investigated by polymerase chain reaction-based restriction fragment length polymorphism analysis, fluorescence-based dideoxy sequencing, or both. For the flat type, the frequency of codon 201Gly of the DCC gene was 64% and 54% in the normal tissue of patients with adenoma with high-grade dysplasia and submucosal carcinoma, respectively. It was 49%, 52%, and 49% in the normal tissue of patients with polypoid-type adenoma with high-grade dysplasia, submucosal carcinoma, and advanced carcinoma, respectively. In the normal tissue, codon 201Gly of the DCC gene was more frequently observed in patients with flat-type adenoma with low-grade dysplasia (67%) than in those with polypoid-type adenoma with low-grade dysplasia (18%) or in normal controls (17%, P < 0.05, chi2 test). Codon 201Arg/Gly polymorphism in tumor tissues did not differ from that in the corresponding normal tissues, except for 10 cases of carcinoma with loss of heterozygosity (LOH). In carcinomas with LOH, preferential loss of the codon 201Arg allele was noted (9/10 cases). These results suggest that codon 201Gly of the DCC gene is not only associated with flat-type colorectal tumors, but that it may serve as a useful genetic marker for identifying groups at higher risk for colorectal cancer.
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PMID:Codon 201Arg/Gly polymorphism of DCC (deleted in colorectal carcinoma) gene in flat- and polypoid-type colorectal tumors. 944 Jun 18

There is vast evidence in support of the idea that accumulated genetic changes (mutations) are the underlying cause of neoplasia development. This multi-step process is aptly illustrated by colorectal carcinoma (CRC), usually developing in the course of decades, and presumably requiring at least seven genetic events to complete its development. In CRC the oncogenes most frequently undergoing mutation are c-k-ras and c-myc, and among tumor suppressant genes--APC, MCC, DCC, p53. An updated model of the molecular bases for adenoma occurrence and its evolution into carcinoma is presented. Inheritance of a single gene only which has undergone mutation augments substantially the predisposition to CRC. This is noted in a clearcut manner in the hereditary syndromes familial adenomatous polyposis (FAP) and hereditary non-polypous colorectal carcinoma (HNPCC). Recent studies along these lines suggest that the genetic defect in FAP increases the incidence of tumor initiation through functional impairment of the APC gene which is a gene regulator of the enhanced colorectal mucosa proliferation. Contrarily, the defect in HNPCC involves mainly the tumor progression through mutation of the DNA repair genes (MMRs), which are regulators of the genome stability. The study of hereditary syndromes give rise to a new concept for the occurrence and development of sporadic and inherited cancer in humans.
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PMID:[The molecular biology and genetics of colorectal carcinoma]. 973 86

We examined 36 cases of human sporadic colon carcinoma and corresponding normal tissue samples to evaluate loss of heterozygosity at the APC and DCC tumor suppressor genes loci using restriction fragment length polymorphism polymerase chain reaction and variable nucleotide tandem repeat analysis. Observed informativity was 83% for APC and 75% for DCC. DNA from 6 (20%) of 30 informative tumors exhibited loss of heterozygosity at the APC locus. Loss of heterozygosity at the DCC locus was observed in 7 (26%) of 27 informative tumor DNAs. Our results support the view that malignant progression is a consequence of more than one genetic change and suggest that inactivation of APC and DCC genes plays a role in a multistep process of colon tumor progression.
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PMID:Loss of heterozygosity of APC and DCC tumor suppressor genes in human sporadic colon cancer. 1009 May 94

Barrett's esophagus carries a 30- to 100-fold increased risk of adenocarcinoma, which is thought to develop via a metaplasia-dysplasia-carcinoma progression. A common genetic abnormality detected in Barrett's adenocarcinoma is loss of heterozygosity (LOH) at the sites of known or putative tumor suppressor genes, of which there are at least 9 associated with esophageal adenocarcinoma. The aim of this study was to identify at which histological stage of carcinogenesis LOH at these sites occur. Microdissection of multiple paraffin-embedded tissue blocks from 17 esophagogastrectomy specimens of adenocarcinoma arising in Barrett's esophagus yielded areas of metaplasia, low-, intermediate- and high-grade dysplasia, and carcinoma. LOH analysis of microdissected tissues was performed using a double polymerase chain reaction technique with 11 microsatellite primers shown previously to have LOH in at least 30% of esophageal adenocarcinomas. Identical LOH was detected in premalignant and malignant tissues in 4 of 17 patients, and was located at 5q21-q22 (D5S346 primer), 17p11.1-p12 (TCF2 primer), 17p13.1 (TP53 primer), 18q21.1 (detected in colon cancer tumor suppressor gene [DCC] primer), and 18q23-qter (D18S70 primer). These results suggest that LOH at the sites of the DCC, adenomatous polyposis coli (APC), and TP53 tumor suppressor genes occur before the development of adenocarcinoma in Barrett's esophagus, and so merit further study as potential biomarkers of neoplastic progression in patients with Barrett's esophagus undergoing endoscopic and histological surveillance.
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PMID:LOH at the sites of the DCC, APC, and TP53 tumor suppressor genes occurs in Barrett's metaplasia and dysplasia adjacent to adenocarcinoma of the esophagus. 1066 31

Colorectal carcinoma is a major cause of death throughout the Western world. It is increasingly recognized that any reduction in mortality must be achieved through the detection and removal of early and precancerous lesions. The primary attention for such a preventive strategy has been the polypoid adenoma and surveillance studies have shown a significant reduction in the incidence of carcinoma through systematic polypectomy of suspicious lesions. A potential problem with such a program, however, is raised by reports from Japan that some carcinomas seem to arise without a precursor polypoid adenoma, that is de novo. Although the histopathologic findings in such reports seem to clearly support this idea, this concept is not widely accepted in the Western world. We undertook a series of immunohistochemical (p53, bcl-2, Mib-1, E-cadherin, CD44, Stromelysin-3), and microsatellite analysis studies (on 17p (p53), 18q (DCC), 5q (APC), 8p, 2p and 1p), on groups of de novo and ex adenoma carcinomas in order to see if differences between the two groups of lesions exist. The results of these studies demonstrate that de novo carcinomas share several phenotypic and genotypic features with ex adenoma carcinoma (similar CD44 in the carcinomas, similar rates of LOH at APC and DCC loci), but have significantly higher rates of LOH at 17p, p53 over-expression and ST-3 expression indicating that tumor progression in de novo carcinoma is accelerated. These findings should help clarify the concept of de novo carcinoma and contribute to wider recognition of this important clinicopathologic entity.
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PMID:[Are there differences between ex adenoma and de novo colorectal carcinomas?]. 1071 4

Seventy malignant, premalignant and histologically normal biopsies from 7 oesophagogastrectomy specimens of adenocarcinomas of the lower oesophagus and gastroesophageal junction were analysed for loss of heterozygosity (LOH) at 9 known or putative gene loci. LOH was detected in 20 of 27 (74%) malignant biopsies, 4 of 7 (57%) biopsies of dysplasia, 2 of 12 (25%) biopsies of histologically normal oesophagus adjacent to adenocarcinoma, and in 2 of 14 (14%) biopsies of histologically normal stomach adjacent to adenocarcinoma. LOH at the VHL, APC, CDKN2 and DCC tumour suppressor and MSH3 mismatch repair gene loci can be detected in histologically normal tissue and in adjacent adenocarcinoma, and are potential markers of early neoplastic progression.
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PMID:Histological and molecular mapping of adenocarcinoma of the oesophagus and gastroesophageal junction: loss of heterozygosity occurs in histologically normal epithelium in the oesophagus and stomach. 1076 62

The worldwide incidence of hepatocellular carcinoma (HCC) is approximately one million cases a year. This makes HCC one of the most frequent human malignancies, especially in Asia and Africa, although the incidence is increasing also in the western world. HCC is a complication of chronic liver disease, with cirrhosis as the most important risk factor. Viral co-pathogenesis makes cirrhosis due to hepatitis B (HBV) and hepatitis C virus (HCV) infection a very important factor in the development of HCC. As curative therapy is often ruled out due to the late detection of HCC, it would be attractive to find parameters which predict malignant transformation in HBV- and HCV-infected livers. This study has used comparative genomic hybridization (CGH) to analyse 26 HCCs (11 non-viral, nine HBV, six HCV) and 12 concurrent dysplasias (five non-viral, five HBV, two HCV). Frequent gain (> or =25% of all tumours) was detected, in decreasing order of frequency, on 8q (69%), 1q (46%), 17q (46%), 12q (42%), 20q (31%), 5p (27%), 6q (27%), and Xq (27%). Frequent loss (> or =25% of all tumours) was found, in decreasing order of frequency, on 8p (58%), 16q (54%), 4q (42%), 13q (39%), 1p (35%), 4p (35%), 16p (35%), 18q (35%), 14q (31%), 17p (31%), 9p (27%), and 9q (27%). Minimal overlapping regions could be determined at multiple locations (candidate genes in parentheses). Minimal regions of overlap for deletions were assigned to 4p14-15 (PCDH7), 8p21-22 (FEZ1), 9p12-13, 13q14-31 (RB1), 14q31 (TSHR), 16p12-13.1 (GSPT1), 16q21-23 (CDH1), 17p12-13 (TP53), and 18q21-22 (DPC4, DCC). Minimal overlapping amplified sites could be seen at 8q24 (MYC), 12q15-21 (MDM2), 17q22-25 (SSTR2, GH1), and 20q12-13.2 (MYBL2, PTPN1). A single high level amplification was seen on 5q21 in an HBV-related tumour. Aberrations appeared more frequent in HBV-related HCCs than in HCV-associated tumours (p=0.008). This was most prominent with respect to losses (p=0.004), specifically loss on 4p (p=0.007), 16q (p=0.04), 17p (p=0.04), and 18q (p=0.03). In addition, loss on 17p was significantly lower in non-viral cancers than in HBV-related HCC (p<0.001). Furthermore, loss on 13q was more prevalent in HCCs in non-cirrhotic livers (p=0.02), thus suggesting a different, potentially more aggressive, pathway in neoplastic progression. A tendency (p=0.07) was observed for loss on 9q in high-stage tumours; no specific changes were found in relation to tumour grade. A subset of the HCC-associated genetic changes was disclosed in the preneoplastic stage, i.e. liver cell dysplasia. This group of dysplasias showed frequent gain on 17q (25%) and frequent loss on 16q (33%), 4q (25%), and 17p (25%). The majority of the dysplasias with alterations revealed genetic changes that were also present in the primary tumour. In conclusion, firstly, this study has provided a detailed map of genomic changes occurring in HCC of viral and non-viral origin, and has suggested candidate genes. Loss on 17p, including the TP53 region, appeared significantly more prevalent in HBV-associated liver cancers, whereas loss on 13q, with possible involvement of RB1, was distinguished as a possible genetic biomarker. Secondly, CGH analysis of liver cell dysplasia, both viral and non-viral, has revealed HCC-specific early genetic changes, thereby confirming its preneoplastic nature. Finally, genes residing in these early altered regions, such as CDH1 or TP53, might be associated with hepatocellular carcinogenesis.
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PMID:Molecular cytogenetic evaluation of virus-associated and non-viral hepatocellular carcinoma: analysis of 26 carcinomas and 12 concurrent dysplasias. 1100 97


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