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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Familial clustering of a disease is defined as the occurrence of the disease within some families in excess of what would be expected from the occurrence in the population. It has been demonstrated for several cancer types, ranging from rare cancers as the adenomatosis-coli-associated colon cancer or the Li-Fraumeni syndrome to more common cancers as breast cancer and colon cancer. Familial clustering, however, is merely an epidemiological pattern, and it does not tell whether genetic or environmental causes or both in combination are responsible for the familial clustering. Familial clustering may be due to genetic predisposition to the disease, but exposure to environmental factors--shared by members of some families, but not by members of other families--may also cause familial clustering and hence mimic genetic inheritance in the study of nuclear families. Based on assumptions regarding the individual steps in the biological process starting with exposure to carcinogens and ending with death from disseminated cancer we suggest that genetic and environmental factors may both be involved in most of these steps. The present paper focuses on research methodologies necessary to discriminate between the effect of genes and family environment in the development of cancer.
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PMID:Genes and family environment in familial clustering of cancer. 788 32

The time course of induction of SOS-like stress responses such as enhanced reactivation (ER) and enhanced mutagenesis (EM) has been investigated in UV-C-irradiated skin fibroblasts from a xeroderma pigmentosum (XP) family, using herpes simplex virus type 1 as a probe. Similar ER studies were performed in a Li-Fraumeni syndrome (LFS) family and in a family with a high incidence of breast, ovarian, and colon cancer. In two XP (complementation group B) patients, with a striking absence of skin tumors even at an age of >40 years, only induction of EM was observed, whereas ER was absent (XPER-). The ER- phenotype was inherited from the father, whereas cells from the mother exhibited normal expression of ER and EM. This suggests that the absence of ER is a hereditary trait that is not correlated with a repair-deficient phenotype. Abnormally high levels of ER were observed in UV-C-exposed skin fibroblasts from rive LFS patients. The inheritance of the ER response was studied in one LFS family. High levels of ER were observed only in cells derived from affected individuals carrying one mutated p53 allele, whereas cells from unaffected family members, carrying two wild-type p53 alleles, exhibited normal ER levels. This result shows that abnormally high levels of ER positively correlate with the occurrence of cancer in affected individuals from a LFS family. Interestingly, abnormally high levels of ER were observed in cells from afflicted as well as from unafflicted members of a family with a high incidence of breast, ovarian, colon, and stomach cancer. This suggests that these latter individuals have inherited a mutated, putative predisposing gene, resulting in abnormal expression of ER, but that cancer had not yet developed. The results indicate that the ER response can possibly be used as a prognostic marker to identify carriers in various hereditary cancer-prone syndromes at an early age.
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PMID:Inheritance of abnormal expression of SOS-like response in xeroderma pigmentosum and hereditary cancer-prone syndromes. 865 7

Colorectal carcinoma rarely affects children and has a dismal prognosis with 5-year survival rates as low as 2.5%-7% despite apparently radical surgery. Here we report the case of an adenocarcinoma of the sigmoid colon in a 15-year-old girl preceded by uncertain abdominal complaints of 5 years' duration. Pathological work-up revealed a tumour with lymph node metastases (pT3NI). Immunohistochemical evidence of p53 overexpression by the tumour cells raised the suspicion of an underlying Li-Fraumeni syndrome. In addition, there were aphthoid ulceration, fissuration of the non-tumorous mucosa, along with a mixed transmural infiltrate composed of macrophages, eosinophils, and non-typical giant cells, which were compatible with simultaneous Crohn's disease. Anamnestic data concerning the occurrence of idiopathic inflammatory bowel disease or colorectal carcinoma in the patient's relatives were non-contributory. The present results suggest a possible relationship between Crohn's disease and colon cancer due to the defective p53 gene product.
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PMID:Adenocarcinoma of the colon developing on the basis of Crohn's disease in childhood. 1127 78

A woman with a family history of brain tumors in her daughter and sister presented with a breast cancer. She subsequently developed two metachronous primary tumors: a small-cell lung cancer and a colon carcinoma. These tumors arose within the internal mammary radiotherapy field and within the field irradiated for ovariolysis. The p53 gene was analyzed in whole blood lymphocytes using a functional assay developed in yeast Saccharomyces cerevisiae, which tests the transcriptional competence of p53. DNA from the colon cancer cells was analyzed by polymerase chain reaction and sequencing. The patient had a germline-inactivating p53 mutation, confirming the diagnosis of Li-Fraumeni syndrome (LFS). The colon tumor and the lung tumor both conserved the mutant p53 allele but had lost the wild-type allele. This observation and the experimental data suggest an abnormal sensitivity of LFS patients to radiogenic carcinogenesis. The indications and extent of radiotherapy in patients with a clinical or molecular diagnosis of LFS should be discussed individually and should take into account the risk of secondary neoplasms arising in the radiation fields.
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PMID:Two metachronous tumors in the radiotherapy fields of a patient with Li-Fraumeni syndrome. 1147 98

Recent evidence identified a genetic and functional link between Chk2 kinase and p53 as a candidate genome integrity checkpoint and a tumour suppressor pathway. Here we report that in human cells, Chk2 and p53 form protein-protein complexes whose abundance increased upon DNA damage, and whose formation was abrogated through cancer associated mutations in the FHA domain of Chk2, or mutations in the tetramerization domain of p53. Whereas among Li-Fraumeni syndrome families mutations of Chk2 or p53 occur in a mutually exclusive manner, we document that the colon cancer cell line HCT-15 concomitantly lacks functions of both Chk2 and p53, the latter demonstrated by a non-invasive reporter assay monitoring p53-dependent transactivation in live cells. Despite the preserved ability of common cancer-derived mutant p53 proteins to bind and potentially 'titrate' activated Chk2, the integrity of the S phase checkpoint response to ionizing radiation remained largely intact and dependent on Chk2 in cells with wild-type, mutant, or no p53. These results provide new mechanistic insights into the Chk2-p53 interplay, suggest how mutations in Chk2 may abrogate its tumour suppressor function, and indicate that compared with individual defects in either Chk2 or p53, concomitant mutations in both of these cell cycle checkpoint regulators may provide some additional selective advantage to tumour cells.
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PMID:Functional impact of concomitant versus alternative defects in the Chk2-p53 tumour suppressor pathway. 1157 48

Rare inherited syndromes that to some extent explain familial glioma include Turcot's syndrome, Li-Fraumeni syndrome and neurofibromatosis types I and II. The majority of families with glioma do not meet the clinical criteria for any of these syndromes. In order to study the genetic origin of familial glioma, tumour DNA (n = 35) or blood samples (n = 8) were collected from 25 families. The glioma tumours were tested for microsatellite instability (MSI) with two markers, BAT25 and BAT26, since glioma is associated with hereditary non-polyposis colon cancer (HNPCC) in Turcot's syndrome. Furthermore, p53 was screened from blood DNA (exons 2-11) with temporal temperature gradient electrophoresis (TTGE) since germline mutations in p53 are seen in Li-Fraumeni syndrome. In gliomas, there is a wide variety of somatic mutations, such as, for instance, in p53, the epidermal growth factor receptor (EGFR) and p16. The tumour suppressor gene PTEN is also often somatically mutated in glioma, therefore it is attractive as a candidate gene for germline mutations in familial glioma. Blood DNA was directly sequenced for mutations in PTEN exons 1-9. The analysis showed that no mutations were found in either of the studied tumour suppressor genes, and no MSI-positive tumours were found. A common polymorphism in p53 at codon 72 (arginine/proline) was found in 6/8 of the patients. Apparently, mutation in the tested tumour suppressor genes or DNA mismatch repair genes does not explain the familial glioma observed in these families.
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PMID:Microsatellite instability, PTEN and p53 germline mutations in glioma families. 1166 37

The CHK2 gene encodes a protein kinase that is important for the regulation of cell cycle arrest after DNA damage. CHK2 acts downstream of ataxia teleangiecstasia mutated (ATM), modulates the function of p53 and may help mediate cell cycle arrest at G2/M by phosphorylation of Cdc25C. Recently, the human homolog of the checkpoint kinase Cds1 (CHK2) has been suggested to be a tumor suppressor gene. Heterozygous germline mutations have been reported in Li-Fraumeni syndrome (LFS), a highly penetrant familial cancer phenotype, and in sporadic colon cancer. LFS is associated with the development of lymphoid malignancies, especially childhood ALL. Therefore, we analyzed the DNA from 143 lymphoid malignancies to determine whether they had mutations of the CHK2 gene. The 14 exons of CHK2 were studied by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and sequencing of aberrantly migrating bands. One missense mutation changing serine to phenylalanine (codon 428) in an evolutionarily highly conserved domain was found in a non-Hodgkin's aggressive lymphoma. Another point mutation in the non-coding region was identified in one of adult T-cell leukemias (ATL) samples. This result suggests that mutation of the CHK2 gene may rarely be involved in the development of selected lymphomas.
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PMID:Analysis of the CHK2 gene in lymphoid malignancies. 1169 18

Recent progress in molecular biology and genetics has improved understanding of the mechanisms of carcinogenesis. However, there are few effective methods for prevention or therapies against cancer based on such elucidated molecular mechanisms of carcinogenesis. We therefore tried to develop novel methods of cancer prevention and therapy based on them. For example, the tumor-suppressor gene p53 is mutated in about 50% of human malignancies or in a cancer-prone family with Li-Fraumeni syndrome. It is known that p53 stimulates the promoter activities of p21/WAF1, gadd45 and bax genes to enhance their expression as a transcriptional factor, resulting in cell cycle arrest, DNA repair and apoptosis, respectively. Therefore, chemical compounds or food factors that can stimulate these genes might compensate for part of the p53 function. As a model of our hypothesis, we found that histone deacetylase inhibitors such as butyrate and trichostatin A dramatically stimulate the p21/WAF1 gene promoter through the Sp1 sites, resulting in cell cycle arrest. We therefore hypothesized that a strategy for up-regulating p53-target genes such as p21/WAF1, gadd45 and bax might be useful for cancer prevention or therapy, and termed this method "Gene-regulating chemoprevention" or "Gene-regulating chemotherapy" against cancer. In fact, butyrate, a short chain fatty acid, exists in colon lumen as a metabolite of dietary fiber, and is believed to be preventive against colon cancer. In conclusion, we proposed that "Gene-regulating chemoprevention" and "Gene-regulating chemotherapy" may be new promising strategies for cancer prevention or therapy, and histone deacetylase inhibitors are good candidates for these strategies. "Gene-regulating chemoprevention" is a particularly suitable model for "Molecular-targeting prevention", which we have proposed recently. We believe that "Molecular-targeting prevention" will become one of the most important concepts in the 21st century for general prevention of a variety of common hereditary or non-hereditary common diseases.
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PMID:[Gene-regulating chemoprevention against cancer--as a model for "molecular-targeting prevention" of cancer]. 1280 65

Germline TP53 mutations predispose to a rare familial cancer syndrome, the Li-Fraumeni Syndrome (LFS), characterized by the early onset of multiple cancers including childhood adrenocortical carcinomas, sarcomas and brain tumors, and breast and colon cancer in young adults. An identical germline mutation at codon 337 in TP53 (R337H) has been shown to be causally related to an increased risk of multiple cancers in unrelated subjects with familial cancer risk in Southern Brazil. Here we have assessed the prevalence of R337H in 750 healthy women participating in a community-based breast cancer screening program in the area of Porto Alegre. The mutant was detected in two participants (0.3%) who were fourth-degree relatives and reported a familial history of cancer at multiple sites that did not match classical criteria for LFS and its variants. Testing in additional family members detected the mutation in three subjects, one of whom developed breast cancer at the age of 36. These findings indicate that R337H may be a low penetrance mutant which predisposes to multiple cancers and occurs in the population of Southern Brazil at a frequency 10-20 times higher than other TP53 mutants commonly associated with LFS.
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PMID:Detection of R337H, a germline TP53 mutation predisposing to multiple cancers, in asymptomatic women participating in a breast cancer screening program in Southern Brazil. 1824 85

We describe a patient who had nine primary malignant tumors and a germline mutation in the p53 tumor-suppressor gene, characteristically found in the Li-Fraumeni syndrome (LFS). A 15-year-old girl with no family history of cancer was referred to our hospital because of pain and swelling of the right knee. Osteosarcoma was diagnosed. The patient received chemotherapy followed by surgery and had a remission. After the age of 28 years, nine primary malignant tumors developed successively, including right breast cancer, colon cancer, malignant fibrous histiocytoma (MFH) of the abdominal wall, right lung double cancers, bilateral breast cancers, and MFH of the left thigh. This is the second highest number of types of primary malignant tumors to be reported in LFS. All tumors were treated by a multidisciplinary approach, including surgery. Genetic analysis revealed a germline missense mutation in the p53 gene (c.659 A > G), resulting in Y220C, which has been reported in three families with LFS. The patient died of lung metastasis from MFH at the age of 37 years. Despite the multiple tumors, repeated induction of remissions resulted in long survival. Our findings suggest that a multidisciplinary approach to treatment, including surgery, is beneficial in patients with LFS.
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PMID:A Japanese patient with Li-Fraumeni syndrome who had nine primary malignancies associated with a germline mutation of the p53 tumor-suppressor gene. 1830 25


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