Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Singapore Polyposis Registry was established in 1989 in Singapore General Hospital. The aim is to provide a central registry service to all doctors in Singapore to facilitate in identification, surveillance and management of families and individuals at high risk of getting colorectal cancer from FAP (Familial Adenomatous Polyposis) and HNPCC (Hereditary Non-polyposis Colorectal Cancer). Both have an autosomal dominant inheritance that gives rise to colorectal cancer at any early age if untreated. They account for 5-6% of all colorectal cancers. Sixteen FAP families with 139 members have been evaluated. Fifty-eight members are affected and 81 are at risk or unaffected. Those who have been screened positive have a much lower risk of cancer (13%) compared with those who presented with the disease (89%) and death from colorectal cancer in the corresponding groups were nil and 58%. Eight HNPCC families with 36 affected and 170 at-risk members have been registered. Colonoscopic surveillance have just started: one case of Dukes' A cancer in a 26 year-old patient, and two cases with polyps have been diagnosed. Advances in molecular genetics and the identification of APC (Adenomatous Polyposis Coli) gene in the FAP locus of Chromosome 5 have made it possible to diagnose FAP genetically. This has important impact on management in terms of prenatal diagnosis and dietary and chemoprevention programmes in addition to surgical intervention.
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PMID:The Singapore Polyposis Registry. 132 51

Oncogene is not categorized as a tumor marker in a strict sense, however, cancer related oncogens play an important role as a biomarker in hereditary malignant tumors in a wide sense. Various suppressor oncogenes have been identified in the autosomal dominant hereditary diseases such as APC, in familial adenomatous polyposis, p53 in Li-Fraumeni syndrome and BRACA 1 and 2 in breast cancer. By identifying the mutation site or deletions of germ line, it is possible to make a presymptomatic diagnosis of those hereditary malignant tumors. There is splendid progress in understanding of DNA repair mechanism. Recently, the mismatch repair genes were cloned as a causing gene of HNPCC. There are another group of genes called nucleotide excision repair genes which are causative genes of various autosomal recessive hereditary diseases such as xeroderama pigmentation. Pro and cons of presymptomatic diagnosis of familial adenomatous polyposis were discussed in a series of 72 patients among 42 family trees.
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PMID:[Role of tumor marker in the presymptomatic diagnosis of hereditary malignant tumors]. 869 15

The genetic understanding of colon cancer susceptibility is advancing very rapidly; it has already had a major impact on clinical management, and we have only seen the beginning. Genes responsible for the two well-defined familial colon cancer syndromes (APC and HNPCC) have been identified. These syndromes can now often be diagnosed by genetic rather than by endoscopic screening of the at-risk individuals in a family. Linkage analysis, although clinically cumbersome, can be performed for families with both APC and HNPCC. In some families, the mutation itself can be determined and a specific mutation assay can be used in the other at-risk members of the family. Both linkage analysis and mutational assays are still largely performed in specialized high-risk cancer clinics. For APC, a truncated protein assay performed on cells isolated from peripheral blood is now commercially available, so the genetic diagnosis of APC can be made by any clinician. It is important, however, to be able to provide appropriate genetic counseling to families before and after genetic testing for these familial colon cancer syndromes. The familial clustering of "sporadic" colon cancer has been suggested to be due to the inheritance of a susceptibility gene or genes. A family history of colon cancer has become an important stratification criteria for colon cancer screening programs. Colonoscopic screening is indicated for individuals with two or more FDRs with colon cancer or with one FDR in whom colon cancer developed under the age of 50 or so. If specific susceptibility genes for sporadic colon cancer are identified, it will be possible to target powerful primary preventive and screening programs to this high-risk population (susceptibility gene carriers).
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PMID:The genetic basis of colorectal cancer risk. 890 98

Recent advances in molecular biology have revealed that the alteration of multiple genes, eg., APC, K-ras, p53, DCC, are involved in multistep colorectal carcinogenesis. Some of these alterations can be used as molecular markers in genetic diagnosis. Genetic diagnoses for colorectal cancer are classified into three categories, eg., 1. identification of the career in the family of patient with hereditary disease such as FPC (Familial Polyposis Coli) or HNPCC (Hereditary Non-Polyposis Colorectal Cancer), 2. early diagnosis of colorectal cancer by identifying gene mutations in the stool, 3. assist for histopathological diagnosis, or risk assessment of the metastasis, recurrence or secondary cancer by molecular means. However, there are several problems in these genetic diagnoses. These consist of two categories, eg., 1. problems in the method of gene analyses or assay system and 2. problems in performing genetic diagnoses itself. The former includes the problem of contamination of different tissue, false positive or negative result in PCR-based analyses, heterogeneity of gene mutation in tumor tissue, and the latter includes the social, ethical or economical problems mainly related to the genetic diagnosis for hereditary colorectal cancers. In this paper, we describe the possibility of genetic diagnosis for colorectal cancers and the current problems, especially from the molecular pathological aspect, in genetic diagnosis.
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PMID:[Molecular-pathological problems of genetic diagnosis for colorectal cancer]. 910 43

Turcot syndrome is characterized by an association of malignant brain tumors and colon cancer developing in the patient's teens. Since the mechanism of carcinogenesis in Turcot syndrome is still unclear, we analysed genetic changes in tumors from a Turcot patient with no family history of the condition. All tumors, including one astrocytoma, three colon carcinomas, and two colon adenomas, exhibited severe replication error (RER), and all colon tumors showed somatic mutations at repeated regions of TGFbetaRII, E2F-4, hMSH3, and/or hMSH6 genes. Somatic APC mutations were detected in three of three colon carcinomas, and somatic p53 mutations were detected in the astrocytoma and two of three colon carcinomas, both of which showed two mutations without allele loss. We also found that normal colon mucosa, normal skin fibroblasts and normal brain tissue from this patient showed respective high frequencies of RER, in contrast to usual HNPCC patients in which RER was very rare in normal tissues. These results suggest that extreme DNA instability in normal tissues causes the early development of multiple cancer in Turcot syndrome. A missense mutation (GAG to AAG) at codon 705 of hPMS2 gene was detected in one allele of this patient, which was inherited from his mother without tumors. Additional unknown germline mutation may contribute to the genetic instability in normal tissues.
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PMID:Drastic genetic instability of tumors and normal tissues in Turcot syndrome. 941 79

Germline mutations in the human MSH2, MLH1, PMS2 and PMS1 DNA mismatch repair (MMR) gene homologues appear to be responsible for most cases of hereditary non-polyposis colorectal cancer (HNPCC; refs 1-5). An important role for DNA replication errors in colorectal tumorigenesis has been suggested by the finding of frequent alterations in the length of specific mononucleotide tracts within genes controlling cell growth, including TGF-beta receptor type II (ref. 6), BAX (ref. 7) and APC (ref. 8). A broader role for MMR deficiency in human tumorigenesis is implicated by microsatellite instability in a fraction of sporadic tumours, including gastric, endometrial and colorectal malignancies. To better define the role of individual MMR genes in cancer susceptibility and MMR functions, we have generated mice deficient for the murine homologues of the human genes MLH1, PMS1 and PMS2. Surprisingly, we find that these mice show different tumour susceptibilities, most notably, to intestinal adenomas and adenocarcinomas, and different mutational spectra. Our results suggest that a general increase in replication errors may not be sufficient for intestinal tumour formation and that these genes share overlapping, but not identical functions.
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PMID:Tumour susceptibility and spontaneous mutation in mice deficient in Mlh1, Pms1 and Pms2 DNA mismatch repair. 950 May 52

Recent advancement of molecular biology disclose responsible genes of FAP(familial adenomatous polyposis) and HNPCC(hereditary non polyposis colorectal cancer). Gardner Syndrome is now categorized as subtype of FAP. Turcot Syndrome is now known as a heterogeneous disease. Turcot Syndrome caused by APC gene develops medulloblastoma and Turcot Syndrome caused by mismatch repair gene develops glioblastoma. Because of the discovery of APC gene, the presymptomatic diagnosis of asymptomatic gene carriers are now available and preventive surgery can be planned. FAP patients with mutated APC gene between codon 1250 and 1464 shows severe phenotype. It is known that FAP patient whose APC gene mutation locates at codon 1309 develops cancer 10 years earlier in comparison to the rest of the cases. Consequently risky rectal mucosa should be removed in this group of patients. As for HNPCC, presymptomatic diagnosis is still not possible because the penetrance rate has not been estimated yet and some additional responsible genes are expected to be discovered. Replication error, mutator phenotype of mismatch repair gene is useful indicator to predict second primary cancers. When the patient in a HNPCC family develops adenoma with microsatellite mistability, preventive colectomy might be one of the surgical option with the informed consent of the patient.
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PMID:[Molecular biological background of FAP and HNPCC, and treatment strategies of both diseases depend upon genetic information]. 969 69

New technologies in molecular biology will allow the improvement of screening, diagnosis and prognosis of colorectal cancer patients. For example the determination of germline mutation in APC or in mismatch repair genes in patient with familial adenomatous polyposis or with HNPCC is now possible. The clinical surveillance can be restricted to the patients with these germline defects. More over the knowledge of somatic genetic alterations in colorectal cancer cells seems to be useful in the determination of prognosis of these patients or in order to predict the chemotherapy response.
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PMID:[The application of molecular technics in the management of colorectal cancer]. 977 89

The epidemiology and molecular biology of colorectal cancer are reviewed with a view to understanding their interrelationship. Risk factors for colorectal neoplasia include a positive family history, meat consumption, smoking, and alcohol consumption. Important inverse associations exist with vegetables, nonsteroidal anti-inflammatory drugs (NSAIDs), hormone replacement therapy, and physical activity. There are several molecular pathways to colorectal cancer, especially the APC (adenomatous polyposis coli)-beta-catenin-Tcf (T-cell factor; a transcriptional activator) pathway and the pathway involving abnormalities of DNA mismatch repair. These are important, both in inherited syndromes (familial adenomatous polyposis [FAP] and hereditary nonpolyposis colorectal cancer [HNPCC], respectively) and in sporadic cancers. Other less well defined pathways exist. Expression of key genes in any of these pathways may be lost by inherited or acquired mutation or by hypermethylation. The roles of several of the environmental exposures in the molecular pathways either are established (e.g., inhibition of cyclooxygenase-2 by NSAIDs) or are suggested (e.g., meat and tobacco smoke as sources of specific blood-borne carcinogens; vegetables as a source of folate, antioxidants, and inducers of detoxifying enzymes). The roles of other factors (e.g., physical activity) remain obscure even when the epidemiology is quite consistent. There is also evidence that some metabolic pathways, e.g., those involving folate and heterocyclic amines, may be modified by polymorphisms in relevant genes, e.g., MTHFR (methylenetetrahydrofolate reductase) and NAT1 (N-acetyltransferase 1) and NAT2. There is at least some evidence that the general host metabolic state can provide a milieu that enhances or reduces the likelihood of cancer progression. Understanding the roles of environmental exposures and host susceptibilities in molecular pathways has implications for screening, treatment, surveillance, and prevention.
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PMID:Colorectal cancer: molecules and populations. 1130 47

The APC I1307K gene mutation is associated with increased colorectal cancer (CRC) risk in Ashkenazi Jews. Factors predicting acceptance of this and other hereditary colon cancer mutation tests in a clinical setting are unknown. We analyzed sex, age, family history, personal history, and gene test results of patients at increased risk for cancer who sought cancer risk counseling at the Johns Hopkins (JH) CRC Risk Assessment Clinic (n = 91), and those submitting samples to the JH Pathology Molecular Diagnostic Laboratory (n = 256) for APC I1307K testing. Of patients seen at the JH Clinic, 77/91 (84.6%) elected APC I1307K testing after pretest counseling (acceptors). There were no statistically significant differences in demographic characteristics between acceptors and decliners. In comparison, only 8 of 57 (14.0%) patients offered HNPCC testing proceeded with testing (P < 0.001). Of 256 individuals tested at the JH laboratory, most were male (61.3%) and most had a personal or family history of colorectal cancer or polyps. Test positivity correlated with increasing risk of colorectal cancer. Acceptance of testing for the APC I1307K mutation is high, with more men than women pursuing counseling and testing. The reported association between the APC I1307K mutation and colon cancer risk was supported by a correlation in these data between personal or family history of CRC or polyps and a gene mutation.
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PMID:Response to genetic counseling and testing for the APC I1307K mutation. 1075 45


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