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Gut Apr 1997Familial adenomatous polyposis (FAP) is caused by germline mutation of the adenomatous polyposis coli (APC) gene on chromosome 5q.
BACKGROUND
Familial adenomatous polyposis (FAP) is caused by germline mutation of the adenomatous polyposis coli (APC) gene on chromosome 5q.
AIMS
This study assessed genotype-phenotype correlations for extraintestinal lesions in FAP.
METHODS
Mutations of the APC gene were compared with the occurrence of seven extraintestinal manifestations in 475 FAP patients from 51 families. The frequency of manifestations was adjusted for different ages of patients using person years of exposure. In pedigrees without identified APC gene mutation, analysis of linkage to chromosome 5q and/or assessment of neoplasms for replication errors characteristic of mutation in mismatch repair genes were performed.
RESULTS
FAP patients from the 42 families (82%) with identified mutations of the APC gene had more frequent expression of extraintestinal manifestations than affected individuals without identified mutations (risk ratio 1.2-4.0; significant difference for cutaneous cysts). The presence of a cutaneous cyst or extraintestinal cancer significantly increased the likelihood of detection of a mutation in the APC gene (94% and 92% respectively; p < 0.05). In patients without identified APC gene mutation, linkage to the APC gene was found in one large family (lod = 5.1, theta 0.01), and replication error phenotype was absent in all 24 neoplasms from 16 members of these nine pedigrees. Expression of pigmented ocular fundus lesions was strongly associated with mutations in codons 541-1309, but no other extraintestinal manifestations were related to mutation position. Multiplicity of extraintestinal manifestations was high with mutation in codons 1465, 1546, and 2621.
CONCLUSIONS
Patients with the colorectal phenotype of FAP but no extraintestinal manifestations may have non-truncating mutations of the APC gene or mutation in a gene other than APC or mismatch repair genes. The site of APC gene mutation is associated with pigmented ocular fundus lesions (codons 542-1309) and predisposition to multiplicity of extraintestinal manifestations (codons 1465, 1546, and 2621).
Topics: Adenomatous Polyposis Coli; Bone Neoplasms; Codon; Cysts; Fundus Oculi; Genes, APC; Genotype; Germ-Line Mutation; Humans; Osteoma; Phenotype; Pigmentation Disorders; Regression Analysis; Skin Diseases
PubMed: 9176082
DOI: 10.1136/gut.40.4.521 -
Cancer Science Apr 2008Accumulation of the beta-catenin protein and transactivation of a certain set of T-cell factor (TCF)-4 target genes by accumulated beta-catenin have been considered... (Review)
Review
Accumulation of the beta-catenin protein and transactivation of a certain set of T-cell factor (TCF)-4 target genes by accumulated beta-catenin have been considered crucial in colorectal carcinogenesis. In the present review, we summarize nuclear proteins that interact with, and regulate, the beta-catenin and TCF and lymphoid enhancer factor (LEF) transcriptional complexes. Our recent series of proteomic studies has also revealed that various classes of nuclear proteins participate in the beta-catenin-TCF-4 complex and modulate its transcriptional activity. Furthermore, the protein composition of the TCF-4-containing nuclear complex is not fixed, but is regulated dynamically by endogenous programs associated with intestinal epithelial cell differentiation and exogenous stimuli. Restoration of the loss-of-function mutation of the adenomatous polyposis coli (APC) gene in colorectal cancer cells does not seem to be a realistic approach with currently available medical technologies, and only signaling molecules downstream of the APC gene product can be considered as targets of pharmacological intervention. Nuclear proteins associated with the beta-catenin-TCF-4 complex may include feasible targets for molecular therapy against colorectal cancer. Recently, an inhibitor of the interaction between CREB-binding protein and beta-catenin was shown to efficiently shut down the transcriptional activity of TCF-4 and induce apoptosis of colorectal cancer cells. We also summarize current strategies in the development of drugs against Wnt signaling.
Topics: Animals; Antineoplastic Agents; Cell Nucleus; Colorectal Neoplasms; Drug Design; Female; Gene Expression Regulation, Neoplastic; Genes, APC; Humans; Male; Mice; Nuclear Proteins; TCF Transcription Factors; Transcription Factor 7-Like 2 Protein; Wnt Proteins; beta Catenin
PubMed: 18177486
DOI: 10.1111/j.1349-7006.2007.00716.x -
Proceedings of the National Academy of... Apr 1993The APC gene has been found to be mutated during the development of sporadic colorectal tumors as well as in the germ line of familial adenomatous polyposis patients. To...
The APC gene has been found to be mutated during the development of sporadic colorectal tumors as well as in the germ line of familial adenomatous polyposis patients. To facilitate the characterization of both normal and mutant APC protein, a series of monoclonal and polyclonal antibodies specific for the APC protein was produced. When lymphoblastoid cell lines derived from seven familial adenomatous polyposis patients with known mutations were analyzed by Western blot, an approximately 300-kDa protein corresponding to the predicted size of full-length APC was detected in all 7 cell lines. In addition, truncated APC proteins corresponding to the product of the known mutated alleles could be detected in 4 of the 7 lines. Similar analysis of 23 colon carcinoma and 9 adenoma cell lines revealed truncated proteins in 24 (75%) of the cell lines. Moreover, 26 (81%) of the colon tumor lines were totally devoid of the normal, full-length protein. In contrast, Western blot analysis of 40 cell lines derived from sporadic tumors of other organs detected only full-length APC. Immunohistochemical analysis of APC in normal colonic mucosa revealed cytoplasmic staining with more intense staining in the basolateral margins of the epithelial cell. This staining was markedly increased in the upper portions of the crypts, suggesting an increased level of expression with maturation. These studies provide some initial clues to the function of the cytoplasmic protein APC and demonstrate the feasibility of identifying APC mutations by direct analysis of the APC protein.
Topics: Adenoma; Adenomatous Polyposis Coli; Adenomatous Polyposis Coli Protein; Animals; Antibodies; Antibodies, Monoclonal; Base Sequence; Blotting, Western; Colon; Colonic Neoplasms; Colorectal Neoplasms; Female; Genes, APC; Humans; Immunohistochemistry; Intestinal Mucosa; Mice; Mice, Inbred Strains; Molecular Sequence Data; Mutation; Neoplasm Proteins; Oligodeoxyribonucleotides; Polymerase Chain Reaction; Tumor Cells, Cultured
PubMed: 8385345
DOI: 10.1073/pnas.90.7.2846 -
Proceedings of the National Academy of... Jan 2017The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to...
The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an Apc (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion.
Topics: Adenomatous Polyposis Coli; Alleles; Animals; Cell Lineage; Cell Plasticity; Colonic Neoplasms; Epigenesis, Genetic; Gene Expression; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Genes, APC; Intestinal Mucosa; Mice; Mutation; Pluripotent Stem Cells
PubMed: 28057861
DOI: 10.1073/pnas.1614197114 -
Journal of Visceral Surgery Apr 2020Nearly 5% of colorectal cancers are hereditary colorectal cancers, including adenomatous polyposis. The aim of this review was to highlight the current management of... (Review)
Review
Nearly 5% of colorectal cancers are hereditary colorectal cancers, including adenomatous polyposis. The aim of this review was to highlight the current management of adenomatous polyposis. The two main genetic conditions responsible for adenomatous polyposis are familial adenomatous polyposis (FAP) (caused by an autosomal dominant mutation of the APC gene) and MUTYH-associated polyposis (MAP) (caused by bi-allelic recessive mutations of the MUTYH (MutY human homolog) gene). FAP is characterized by the presence of >1000 polyps and a young age at diagnosis (mean age of 10). In the absence of screening, the risk of colorectal cancer at age 40 is 100%. It is recommended to start screening at the age of 10-12 years. For patients with FAP and MAP, it is also recommended to screen the upper gastrointestinal tract (stomach and duodenum). In FAP, prophylactic surgery aims to reduce the risk of death without impairment of patient quality of life. The best age for prophylactic surgery is not well-defined; in Europe, prophylactic surgery is usually performed at age 20 as the risk of cancer increases sharply during the third decade. There are three main surgical procedures employed: total colectomy with an ileorectal anastomosis, restorative coloproctectomy with a J pouch anastomosis and coloproctectomy with a stoma. Restorative coloproctectomy with J pouch anastomosis is the reference procedure; however, disease can vary in severity from one patient to another and this must be taken into account to decide which procedure should be performed. In conclusion, the management of adenomatous polyposis is complex but is well-defined by guidelines, particularly in France.
Topics: Adenomatous Polyposis Coli; Age Factors; Anastomosis, Surgical; Colectomy; DNA Glycosylases; Endoscopy, Gastrointestinal; Genes, APC; Genetic Markers; Humans; Laparoscopy; Mutation; Quality of Life
PubMed: 32113818
DOI: 10.1016/j.jviscsurg.2019.12.003 -
European Journal of Cancer (Oxford,... Sep 2010While germline mutations in the adenomatous polyposis coli (APC) gene cause the hereditary colon cancer syndrome (familial adenomatous polyposis (FAP)), the role of...
While germline mutations in the adenomatous polyposis coli (APC) gene cause the hereditary colon cancer syndrome (familial adenomatous polyposis (FAP)), the role of common germline APC variants in sporadic adenomatous polyposis remains unclear. We studied the association of eight APC single nucleotide polymorphisms (SNPs), possibly associated with functional consequences, and previously identified gene-environment (dietary fat intake and hormone replacement therapy (HRT) use) interactions, in relation to advanced colorectal adenoma in 758 cases and 767 sex- and race-matched controls, randomly selected from the screening arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Cases had at least one verified advanced adenoma of the distal colon; controls, a negative sigmoidoscopy. We did not observe an association between genotypes for any of the eight APC SNPs and advanced distal adenoma risk (P(global gene-based)=0.92). Frequencies of identified common haplotypes did not differ between cases and controls (P(global haplotype test)=0.97). However, the risk for advanced distal adenoma was threefold higher for one rare haplotype (cases: 2.7%; controls: 1.6%) (odds ratio (OR)=3.27; 95% confidence interval (CI)=1.08-9.88). The genetic association between D1822V and advanced distal adenoma was confined to persons consuming a high-fat diet (P(interaction)=0.03). Similar interactions were not observed with HRT use. In our large, nested case-control study of advanced distal adenoma and clinically verified adenoma-free controls, we observed no association between specific APC SNPs and advanced adenoma. Fat intake modified the APC D1822V-adenoma association, but further studies are warranted.
Topics: Adenomatous Polyposis Coli; Aged; Case-Control Studies; Dietary Fats; Female; Genes, APC; Genotype; Germ-Line Mutation; Haplotypes; Hormone Replacement Therapy; Humans; Male; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors
PubMed: 20510605
DOI: 10.1016/j.ejca.2010.04.020 -
BMC Biology Jan 2023Methods for the long-term in situ transduction of the unperturbed murine intestinal epithelium have not been developed in past research. Such a method could speed up...
BACKGROUND
Methods for the long-term in situ transduction of the unperturbed murine intestinal epithelium have not been developed in past research. Such a method could speed up functional studies and screens to identify genetic factors influencing intestinal epithelium biology. Here, we developed an efficient method achieving this long-sought goal.
RESULTS
We used ultrasound-guided microinjections to transduce the embryonic endoderm at day 8 (E8.0) in utero. The injection procedure can be completed in 20 min and had a 100% survival rate. By injecting a small volume (0.1-0.2 μl) of concentrated virus, single shRNA constructs as well as lentiviral libraries can successfully be transduced. The new method stably and reproducibly targets adult intestinal epithelium, as well as other endoderm-derived organs such as the lungs, pancreas, liver, stomach, and bladder. Postnatal analysis of young adult mice indicates that single transduced cells at E8.0 gave rise to crypt fields that were comprised of 20-30 neighbouring crypts per crypt-field at 90 days after birth. Lentiviral targeting of Apc mutant and wildtype mice revealed that heterozygous loss of Apc function suppresses the developmental normal growth pattern of intestinal crypt fields. This suppression of crypt field sizes did not involve a reduction of the crypt number per field, indicating that heterozygous Apc loss impaired the growth of individual crypts within the fields. Lentiviral-mediated shRNA knockdown of p53 led to an approximately 20% increase of individual crypts per field in both Apc and Apc mice, associating with an increase in crypt size in Apc mice but a slight reduction in crypt size in Apc mice. Overall, p53 knockdown rescued the reduction in crypt field size in Apc-mutant mice but had no effect on crypt field size in wildtype mice.
CONCLUSIONS
This study develops a novel technique enabling robust and reproducible in vivo targeting of intestinal stem cells in situ in the unperturbed intestinal epithelium across different regions of the intestine. In vivo somatic gene editing and genetic screening of lentiviral libraries has the potential to speed up discoveries and mechanistic understanding of genetic pathways controlling the biology of the intestinal epithelium during development and postnatal life. The here developed method enables such approaches.
Topics: Mice; Animals; Mice, Transgenic; Tumor Suppressor Protein p53; Genes, APC; Intestinal Mucosa; Stem Cells
PubMed: 36627630
DOI: 10.1186/s12915-022-01466-1 -
Molecular and Cellular Biology May 1996The Wnt-1 proto-oncogene induces the accumulation of beta-catenin and plakoglobin, two related proteins that associate with and functionally modulate the cadherin cell...
The Wnt-1 proto-oncogene induces the accumulation of beta-catenin and plakoglobin, two related proteins that associate with and functionally modulate the cadherin cell adhesion proteins. Here we have investigated the effects of Wnt-1 expression on the tumor suppressor protein APC, which also associates with catenins. Expression of Wnt-1 in two different cell lines greatly increased the stability of APC-catenin complexes. The steady-state levels of both catenins and APC were elevated by Wnt-1, and the half-lives of both beta-catenin and plakoglobin associated with APC were also markedly increased. The stabilization of catenins by Wnt-1 was primarily the result of a selective increase in the amount of uncomplexed, monomeric beta-catenin and plakoglobin, detected both by affinity precipitation and size-exclusion chromatography of cell extracts. Exogenous expression of beta-catenin was possible in cells already responding to Wnt-1 but not in the parental cells, suggesting that Wnt-1 inhibits an essential regulatory mechanism for beta-catenin turnover. APC has the capacity to oppose this Wnt-1 effect in experiments in which overexpression of the central region of APC significantly reduced the size of the monomeric pool of beta-catenin induced by Wnt-1. Thus, the Wnt-1 signal transduction pathway leads to the accumulation of monomeric catenins and stabilization of catenin complex formation with both APC and cadherins.
Topics: Adenomatous Polyposis Coli Protein; Animals; Blotting, Western; Cadherins; Cell Line; Cell Membrane; Cytoskeletal Proteins; Desmoplakins; Electrophoresis, Polyacrylamide Gel; Gene Expression; Genes, APC; Models, Biological; Protein Binding; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Recombinant Proteins; Trans-Activators; Transfection; Wnt Proteins; Wnt1 Protein; Zebrafish Proteins; beta Catenin; gamma Catenin
PubMed: 8628279
DOI: 10.1128/MCB.16.5.2128 -
Cancer Science Jan 2007Colon cancer arises through different histological stages representing different genetic and epigenetic alterations. The Apc(Min/+) mouse has a point mutation at the Apc... (Review)
Review
Colon cancer arises through different histological stages representing different genetic and epigenetic alterations. The Apc(Min/+) mouse has a point mutation at the Apc gene, and it is considered to be a model for human familial adenomatous polyposis. Our previous studies have revealed the presence of a number of intramucosal microadenomas in the colons of Apc(Min/+) mice, in which only a few macroscopic tumors were recognized. These observations suggest that there are two distinct stages for colon carcinogenesis in Apc(Min/+) mouse, and the Apc(Min/+) mouse is regarded as a good model to study multistage colon carcinogenesis. A number of genes that modify intestinal tumorigenesis have been identified using Apc mutant mice combined with other mutant mice. It has become apparent that epigenetic modification strongly affects intestinal tumorigenesis in Apc(Min/+) mice. We herein describe the different stages of colon tumorigenesis and their modifiers, and discuss the possible application of Apc mutant mice in order to better understand the molecular mechanisms of multistage carcinogenesis in the large bowel of humans.
Topics: Animals; Colonic Neoplasms; Disease Models, Animal; Disease Progression; Epigenesis, Genetic; Genes, APC; Humans; Mice; Mice, Mutant Strains; Models, Biological; Mutation; Precancerous Conditions
PubMed: 17052257
DOI: 10.1111/j.1349-7006.2006.00348.x -
Familial Cancer Apr 2021Germline variants in the APC and MUTYH genes contribute to colorectal cancer (CRC) and adenoma risk, though may occur with varying frequencies in individuals of...
Germline variants in the APC and MUTYH genes contribute to colorectal cancer (CRC) and adenoma risk, though may occur with varying frequencies in individuals of different ancestries. The aim of this study was to evaluate the prevalence of APC, monoallelic MUTYH and biallelic MUTYH germline variants in Ashkenazi Jewish (AJ) and Other Ancestry (OA) individuals with colorectal adenomas. We studied 7225 individuals with colorectal adenomas who had germline APC and MUTYH testing at a commercial laboratory. Cross-sectional medical history data were extracted from provider-completed test requisition forms. We performed bivariate analysis to compare the frequency of APC and MUTYH variants between AJ and OA, and examined APC p.I1307K and monoallelic MUTYH carrier phenotypes using logistic regression. Pathogenic APC variants occurred in 38/285 AJ (13%) and 1342/6940 OA (19%; P = 0.09); biallelic MUTYH variants in 2/285 (1%) AJ and 399/6940 (6%) OA (P < 0.0001); APC p.I1307K in 35/285 (12%) AJ and 29/6940 (1%) OA (P < 0.0001); and monoallelic MUTYH in 2/285 (1%) AJ and 133/6940 (2%) OA (P = 0.06). Monoallelic MUTYH variants were significantly associated with having a personal history of CRC, regardless of ancestry (OR 1.78; 95% CI 1.21-2.49; P < 0.01), but no significant association was found between APC p.I1307K variants and personal history of CRC (OR 1.38; 95% CI 0.79-2.44; P = 0.26). Ashkenazim with colorectal adenomas rarely have monoallelic or biallelic MUTYH variants, suggesting different genetic etiologies for polyposis in AJ compared to OA individuals. AJ ancestry assessment may be important in clinical evaluation for polyposis.
Topics: Adenoma; Cohort Studies; Colorectal Neoplasms; DNA Glycosylases; Female; Gene Frequency; Genes, APC; Genetic Testing; Germ-Line Mutation; Humans; Jews; Male; Middle Aged; Odds Ratio; Phenotype
PubMed: 32743790
DOI: 10.1007/s10689-020-00198-x