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PubMed1994

A targeted chain-termination mutation in the mouse Apc gene results in multiple intestinal tumors.

Germ-line mutations in the human adenomatous polyposis coli (APC) gene result in familial adenomatous polyposis, an autosomal dominant disorder characterized by the early onset of multiple adenomatous polyps in the large bowel with a high likelihood of developing colorectal carcinomas. To understand the role of APC in intestinal tumor formation, we have introduced a chain-termination mutation in the 15th exon of the mouse Apc gene and employed it to modify the endogenous gene by homologous recombination in embryonic stem cells. Mice which are heterozygous for the Apc gene modification progressively develop intestinal tumors in a manner that is similar to that observed in patients with familial adenomatous polyposis and in mice which carry a mutation called multiple intestinal neoplasia (Min). Our results indicate that the Apc gene modification is a critical event in the initiation of intestinal tumor formation and results in an autosomal dominant predisposition toward development of spontaneous colonic and intestinal tumors in mice.

Adenomatous Polyposis Coli↗
PubMed1981

Nondegradation of fecal cholesterol in subjects at high risk for cancer of the large intestine.

In previous studies subjects with familial polyposis, the autosomal dominant disease leading to colon cancer, excreted higher levels of fecal cholesterol than normal subjects, with decreased conversion to degradation products. Findings suggested fecal cholesterol degradation as a marker of hereditary predisposition to colon cancer. Current measurements now have shown that affected individuals and asymptomatic progeny in a second population group with inherited predisposition to colon cancer are low converters of fecal cholesterol. The latter group consisted of highly colon cancer prone families without polyposis, in which patterns of inheritance similar to the autosomal dominant pattern of familial polyposis were observed. 24-h stool collections were obtained from 72 subjects who consumed mixed western diets. Mean percent degradation of fecal cholesterol to coprostanol, coprostanone, cholestanol, and cholestanone revealed significant decreases in fecal cholesterol conversion in affected and asymptomatic subjects in colon cancer prone families without polyposis (P < 0.001) compared to controls. This is in addition to those with familial polyposis (P < 0.001), and extends this marker of colon cancer susceptibility to a second population group with hereditary predisposition to colonic neoplasia.

Cholesterol↗
PubMed2005

beta-Catenin-accumulated crypts in the colonic mucosa of juvenile ApcMin/+ mice.

Although Apc(Min/+) mice are widely used for an animal model of human familial adenomatous polyposis (FAP), a majority of intestinal polyps locate in the small intestine. We recently reported that numerous beta-catenin-accumulated crypts (BCAC), which are reliable precursor lesions for colonic adenocarcinoma, develop in the large bowel of aged Apc(Min/+) mice. In this study, we determined the presence and location of BCAC in the large intestine of juvenile Apc(Min/+) mice (3 and 5 weeks of age). Surprisingly, BCAC were noted in the colon of even Apc(Min/+) mice of both ages, and mainly located in the distal and middle segments of the colon. Also, a few microadenomas were detected in Apc(Min/+) mice of 5-week old. Our results may indicate need of further investigation of the colorectal mucosa of Apc(Min/+) mice for examining colorectal carcinogenesis using Apc(Min/+) mice.

Adenoma↗
PubMed2005

Spectral markers in preneoplastic intestinal mucosa: an accurate predictor of tumor risk in the MIN mouse.

BACKGROUND: We have reported recently that microarchitectural analysis of the histologically normal mucosa using a novel optics technology, four-dimensional elastic light scattering fingerprinting (ELF), provided unprecedented sensitivity for early detection of colon carcinogenesis. In the present study, we explored the ability of four-dimensional ELF to identify an inherited predisposition to colorectal cancer, an issue of considerable importance for optimizing population screening strategies. METHODS: We used the MIN mouse, a model whose germ line adenomatous polyposis coli truncation leads to spontaneous intestinal tumorigenesis, thus replicating the human syndrome, familial adenomatous polyposis. Spectral markers were assessed by four-dimensional ELF analysis in MIN mice at preneoplastic time points and compared with age-matched controls (C57BL6 mice with wild-type adenomatous polyposis coli). To assess the responsiveness of spectral markers to chemopreventive agents, a subset of MIN mice was supplemented with celecoxib 1,500 ppm. RESULTS: Spectral slope, fractal dimension, and principal component 3 were dramatically altered in the uninvolved MIN mouse mucosa at the earliest time points. Furthermore, alteration in spectral variables increased over time, consonant with the microarchitectural underpinnings of subsequent tumorigenesis. Additionally, these markers spatially correlated with future adenoma development (small intestine > colon). Short-term treatment with the potent chemopreventive agent, celecoxib, resulted in near normalization of fractal dimension and principal component 3. CONCLUSIONS: We report, for the first time, that spectral markers, assayed by four-dimensional ELF, were able to sensitively identify a genetic predisposition for intestinal tumorigenesis before the occurrence of phenotypic manifestations. Moreover, the reversal of spectral markers by celecoxib treatment supports the neoplastic relevance.

Animals↗
PubMed1995

Peutz-Jeghers syndrome with osseous metaplasia of the intestinal polyps.

A case of Peutz-Jeghers syndrome (PJS) with osseous metaplasia in three of 15 hamartomatous polyps of the small intestine is reported. At 35 years of age, the patient was diagnosed as having PJS by cutaneous pigmentation around the mouth and polyposis of the stomach, duodenum and intestine. Fifty-two polys of the large intestine were resected, which were characteristic of those of PJS. Three of them showed adenomatous and carcinomatous changes, but there was no osseous metaplasia in any of the resected polyps. At age 40, he had surgery under the diagnosis of intestinal obstruction. There were 15 polyps in the resected jejunum. These polyps were also characteristic of those of PJS. Additionally, three of these polyps were accompanied by osseous metaplasia. Histologically, mature bone formation and calcification were found close to the hyperplastic glands in the submucosa or in the propriate muscle. Malignant transformation was not observed. Osseous metaplasia is extremely rare in benign polyps, and it has not been reported in hamartomatous polyps of PJS to date. The knowledge of this association may be helpful in the clinical diagnosis of this benign lesion in PJS.

Adult↗
PubMed2002

Identification of the modifier of Min 2 (Mom2) locus, a new mutation that influences Apc-induced intestinal neoplasia.

Min (Multiple intestinal neoplasia) mice carry a dominant mutation in the adenomatous polyposis coli (Apc) gene and develop multiple adenomas throughout their intestinal tract (Moser et al. 1990; Su et al 1992). Polyp multiplicity in Min mice is greatly influenced by genetic background. A modifier locus, Mom1 (Modifier of Min 1), was identified and localized to distal mouse chromosome 4 (Moser et al. 1992; Dietrich et al. 1993), and accounts for some of the genetic variance in polyp multiplicity. Mom1 is a semidominant modifier of polyp size and multiplicity in Min mice (Gould and Dove 1997), and encodes the secretory type II nonpancreatic phospholipase A2 (Pla2g2a) gene (MacPhee et al. 1995; Cornier et al. 1997, 2000). We now report the identification of a second Modifier of Min 2 (Mom2) locus that is the result of a spontaneous mutation. One resistant Mom2 allele can suppress 88%-95% of polyps detected in Apc(Min)/+ mice, indicating that Mom2 acts in a dominant fashion. Linkage analysis has localized Mom2 to distal mouse chromosome 18. The effects of the Mom2 locus on reducing polyp multiplicity are stronger than the effects of the Mom1 locus, in both the small and large intestines. Some Apc(Min)/+ mice that carried one resistant Mom2 allele were tumor-free at 21 weeks of age, even in the absence of a resistant Mom1 allele. Thus, the resistant Mom2 allele can, in some cases, completely suppress the penetrance of the Apc(Min) mutation.

Adenomatous Polyposis Coli↗
PubMed1999

Lymphoma of the gastrointestinal tract.

Non-Hodgkin's lymphoma (NHL) of the gastrointestinal (GI) tract accounts for 4% to 20% of all NHLs and is the most common extranodal site of presentation. The stomach is the major organ involved by GI lymphoma. Helicobacter pylori infection, immunosuppression after solid-organ transplantation, celiac disease, inflammatory bowel disease, and human immunodeficiency virus (HIV) infection may be risk factors for GI lymphoma. A significant proportion of gastric lymphomas are of low-grade histology and arise from mucosal-associated lymphoid tissue (MALT). Such MALT lymphomas may be associated with H. pylori infection and may undergo complete regression following eradication of H. pylori. Lymphoma of the small bowel, colon, and rectum may also occur, but are less common than gastric lymphoma. Distinct clinicopathologic entities, such as primary intestinal T-cell lymphoma, immunoproliferative small intestinal disease, and multiple lymphomatous polyposis have been described. Surgery, radiation therapy, and chemotherapy have been used in the treatment of GI lymphomas. However, the optimal management of these lymphomas has never been determined by prospective randomized clinical trials. Such trials by cooperative groups are needed to answer many of the vital unanswered questions concerning extranodal lymphomas of the GI tract.

Gastrointestinal Neoplasms↗
PubMed2001

Resveratrol inhibits intestinal tumorigenesis and modulates host-defense-related gene expression in an animal model of human familial adenomatous polyposis.

We studied the effect of oral administration of resveratrol, a natural constituent of grapes, on tumorigenesis in Min mice. Min mice are congenic mice genetically predisposed to develop intestinal tumors as a result of a mutation of the Apc gene. Resveratrol (0.01% in the drinking water containing 0.4% ethanol) was administered for seven weeks to Min mice starting at five weeks of age. The control group was fed the same diet and received water containing 0.4% ethanol. Resveratrol prevented the formation of colon tumors and reduced the formation of small intestinal tumors by 70%. Comparison of the expression of 588 genes in the small intestinal mucosa showed that resveratrol downregulated genes that are directly involved in cell cycle progression or cell proliferation (cyclins D1 and D2, DP-1 transcription factor, and Y-box binding protein). In addition, resveratrol upregulated several genes that are involved in the recruitment and activation of immune cells (cytotoxic T lymphocyte Ag-4, leukemia inhibitory factor receptor, and monocyte chemotactic protein 3) and in the inhibition of the carcinogenic process and tumor expansion (tumor susceptibility protein TSG101, transforming growth factor-beta, inhibin-beta A subunit, and desmocollin 2). Our data highlight the complexity of the events associated with intestinal tumorigenesis and the multiplicity of the molecular targets of resveratrol. The high potency and efficacy of resveratrol support its use as a chemopreventive agent in the management of intestinal carcinogenesis.

Adenomatous Polyposis Coli↗
PubMed1999

Adenomatous polyposis coli protein (APC)-independent regulation of beta-catenin/Tcf-4 mediated transcription in intestinal cells.

Alterations in the transcriptional activity of the beta-catenin-Tcf complex have been associated with the earlier stages of colonic transformation. We show here that the activation of protein kinase C by the phorbol ester PMA in several intestinal cell lines increases the levels of beta-catenin detected in the nucleus and augments the transcriptional activity mediated by beta-catenin. The response to PMA was not related to modifications in the cytosolic levels of beta-catenin and was observed not only in cells with wild-type adenomatous polyposis coli protein (APC) but also in APC-deficient cells. Binding assays in vitro revealed that PMA facilitates the interaction of the beta-catenin with the nuclear structure. Our results therefore show that beta-catenin-mediated transcription can be regulated independently of the presence of APC.

Adenomatous Polyposis Coli Protein↗
PubMed2002

Push-enteroscopy series: diagnostic and therapeutic efficacy.

OBJECTIVE: To analyse the diagnostic efficacy of oral push-type enteroscopy (PE) according to indications. To assess evolution in patients with occult gastrointestinal bleeding (OGIB) according to findings and endoscopic therapy. METHODS: 204 PE performed in 167 patients: OGIB: 117, Crohn's disease: 34, radiological abnormalities: 21; chronic diarrhoea: 12; intestinal sub-occlusion: 11; polyposis: 7; other: 2. We followed clinical outcome in 72 patients after PE for OGIB. They were separated according to findings and endoscopic therapy: no findings: 32; no treated angiodysplasia: 10; treated angiodysplasia: 20; other lesions: 10. We evaluated the number of admissions and transfusional requirements before and after PE, re-bleeding and surgical treatment. Statistics were performed using Student's t test and Chi-square test (statistical significance p < 0.05). RESULTS: We diagnosed lesions in 65.8% PE for OGIB, angiodysplasia being the more frequent finding (33.3%). We found lesions before Treitz in 15.4% A higher diagnostic efficacy was seen in active bleeding (83.4%) versus anaemia (52.2%), p < 0.05. After PE both admissions and transfusional requirements decreased in all subgroups specially in treated angiodysplasias and other lesions, nearly reaching statistical significance (p = 0.07). Re-bleeding occurred in 50% of non-treated lesions versus 20-25% in treated lesions. We found lesions in 47% of PE for Crohn's disease, in 52.4% for radiological abnormalities, in 41.6% for chronic diarrhoea and in 0% for intestinal sub-occlusion. CONCLUSIONS: PE is efficient in the diagnosis and therapy of patients with OGIB, Crohn's disease and radiological abnormalities. Its usefulness is controversial in the study of chronic diarrhoea and intestinal sub-occlusion.

Adolescent↗
PubMed2002

One dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) or 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) induces tumours in Min/+ mice by truncation mutations or LOH in the Apc gene.

The C57BL/6J-Min/+ (multiple intestinal neoplasia) mouse has a heterozygous nonsense Apc(Min) (adenomatous polyposis coli) mutation, and numerous adenomas spontaneously develop in the intestine. Neonatal exposure of Min/+ mice to the food carcinogens 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) or 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (one injection of 50mg/kg) increased the number of small intestinal tumours about three- and two-fold, respectively. The number of colonic tumours was only increased in males. We examined whether the wild-type Apc allele was affected in intestinal tumours induced by either PhIP or IQ. In spontaneously formed and in IQ-induced small intestinal and colonic tumours from these mice, the main mechanism for tumour induction was loss of wild-type Apc allele, i.e. loss of heterozygosity (LOH). In contrast to the IQ-induced (84% LOH) and spontaneously (88% LOH) formed tumours, only 55% of the PhIP-induced small intestinal tumours from males showed LOH. Tumours that apparently had retained the wild-type Apc allele were further analysed for the presence of truncated Apc proteins by the in vitro synthesised protein (IVSP) assay. Truncated Apc proteins, indicating truncation mutations in exon 15 of the Apc gene, were detected in two of the 12 PhIP-induced tumours in segment 2 (codons 686-1217), and two of five IQ-induced tumours, one in segment 2 and the other in segment 3 (codons 1099-1693). Three of these four mutations, all in segment 2 of the Apc gene, were confirmed by sequencing. The PhIP-induced mutations were detected at codon 1125 (C deletion) and 1130 (G-T transversion), and the IQ-induced mutation was at codon 956 (C-T transition). Importantly, no truncated proteins were detected in tumours from unexposed mice with apparently retained wild-type Apc allele. These results show that one injection of either PhIP or IQ induces intestinal tumours in the Min/+ mice by inactivation of the wild-type Apc allele either by causing LOH or truncation mutations.

Adenomatous Polyposis Coli Protein↗
PubMed2005

Surgical treatment and long-term outcome of patients with familial adenomatous polyposis: 16 years experience at the Tel Aviv Sourasky Medical Center.

BACKGROUND: Restorative proctocolectomy eliminates the risk of colorectal cancer in patients with familial adenomatous polyposis. Complications and extra-intestinal manifestations are inherent to the procedure. OBJECTIVES: To evaluate operative procedures, complications, early and late results and long-term functional outcome in FAP patients operated in our department. METHODS: The study group included all patients with FAP who were operated between 1988 and 2003. Demographic data, length of follow-up, complications, colorectal cancer, pouch function and extracolonic manifestations were recorded. RESULTS: Median age at surgery was 33 years (range 13-61 years). The final operative breakdown was: 48 proctocolectomies, 41 ileal pouch-anal anastomoses, 2 Kock's pouch, 5 permanent ileostomies, and 2 colectomies with ileorectal anastomosis. There was no perioperative mortality. Early and late complications occurred in 20 and 9 patients, respectively. Twelve patients required reoperation. Colorectal carcinoma was diagnosed in eight patients, three of whom were in an advanced stage. The mean follow-up was 74 months (range 3-288 months). Four patients were lost to follow-up. Extracolonic manifestations developed in 38 patients, including desmoid tumors (in 12), duodenal adenomas (in 9), pouch adenomas (in 5), and rectal stump adenomas (in 3). Two patients died (4%) because of desmoid tumor and malignant fibrous histiocytoma. At last follow-up, 37 IPAA patients have (median) six bowel movements/24 hours and good fecal control. CONCLUSIONS: Restorative proctocolectomy can be performed with low mortality, acceptable morbidity, and good functional results. Patients should be closely followed after surgery for development of other manifestations of the syndrome. Relatives of the affected patients should be referred to a specialist multidisciplinary clinic.

Adenomatous Polyposis Coli↗
PubMed2005

Colonic surgery in patients with juvenile polyposis syndrome: a case series.

PURPOSE: Juvenile polyposis syndrome is characterized by multiple hamartomatous polyps in the large intestine. When indicated, the surgical choices in symptomatic juvenile polyposis syndrome patients are colectomy with ileorectal anastomosis or proctocolectomy with pouch. The aim of this study was to evaluate the long-term outcomes of the surgical options in juvenile polyposis syndrome patients who present with symptomatic colonic polyps. METHODS: The charts of all juvenile polyposis syndrome patients who had had at least one colonic operation since 1953 in our institution were reviewed. The following data were abstracted: demographics, the number and site of the polyps, symptoms, the intervals and types of the colonic operation, follow-up, and the patients' current status. RESULTS: There were 13 patients (6 males) with a median age of 10 years (range, 1-50 years) at the time of diagnosis. Patients had colonic (n = 13), rectal (n = 12), and gastric (n = 6) polyps. Rectal bleeding (n = 11) was the most common presenting symptom. Three patients underwent proctectomy as the initial operation. Although a rectum-preserving operation was initially performed in ten patients, a subsequent proctectomy was required in five of them within a median of 9 years (range, 6-34 years). Therefore, eight patients had their rectum removed during the study period; five had an ileal pouch-anal anastomosis, one had a Koch pouch as a restorative surgery, and two had an end ileostomy. No relation was observed between the number of colonic and rectal polyps and the type of surgery or the need for proctectomy. Patients were followed up a median of 3 years (range, 2-24 years) after their ultimate operations. During this period, one patient (20 percent) who underwent restorative proctectomy and 4 patients (80 percent) whose rectums were preserved required multiple endoscopic polypectomies for recurrent polyps in the pouch (first patient) or their rectums (the other four patients). The patient who underwent the Koch procedure required surgery for recurrent polyps in her pouch. CONCLUSIONS: One-half of the patients who initially underwent rectal preservation required subsequent proctectomy. The number of colonic or rectal polyps does not influence the choice of the surgical procedure. Both restorative proctocolectomy and subtotal colectomy with ileorectal anastomosis need endoscopic follow-up because of the high recurrence rates of juvenile polyps in the remnant rectum or pouch.

Adenomatous Polyposis Coli↗
PubMed1990

The association between thyroid neoplasia and intestinal polyps.

Recent reports have suggested an association between familial adenomatous polyposis and papillary carcinoma of the thyroid. This report describes four patients, each with intestinal polyps and thyroid or thyroglossal cyst carcinoma. One patient had a medullary rather than papillary carcinoma of the thyroid and in another the intestinal polyps were due to Peutz-Jeghers syndrome. This may indicate a wider association between thyroid carcinoma and intestinal polyps than has previously been recognised.

Adult↗
PubMed1999

Intestinal dysplasia and adenoma in transgenic mice after overexpression of an activated beta-catenin.

Mutations in the adenomatous polyposis coli gene or activating mutations in the beta-catenin gene itself are thought to be responsible for the excessive beta-catenin signaling involved in intestinal carcinogenesis. We generated transgenic mice that expressed large amounts of a NH2-terminally truncated mutant beta-catenin (deltaN131beta-catenin) in the intestine. These mice had multifocal dysplastic lesions in the small intestine, reminiscent of the early lesions observed in the mouse models of familial adenomatous polyposis. The number of apoptotic cells in the villi of these transgenic mice was 3-4-fold higher than in nontransgenic mice. Expression of the truncated beta-catenin mutant in the kidney led to the development of severe polycystic kidney disease. Our findings support the concept that deregulation of the beta-catenin signaling pathway is the major oncogenic consequence of adenomatous polyposis coli mutations in intestinal neoplasia.

Adenoma↗
PubMed2006

Role of c-Myc in intestinal tumorigenesis of the ApcMin/+ mouse.

The c-MYC oncogene plays an important role in tumorigenesis and is commonly highly expressed in gastrointestinal cancers. In colon cells, c-MYC is regulated by the adenomatous polyposis coli (Apc) tumor suppressor gene. Multiple intestinal neoplasia (ApcMin/+ or Min) mice are heterozygous for a truncating Apc mutation and serve as a model of familial adenomatous polyposis (FAP) disease. To study the role of c-Myc in the mutant Apc-mediated colon tumorigenesis, we have developed a transgenic mouse with the conditional deletion of the floxed c-Myc alleles in the intestinal crypts of ApcMin/+ mice (ApcMin/+; c-Mycfl/fl). The floxed c-Myc deletion was initiated via a Cre recombinase controlled by the intestine-specific transcriptional regulatory elements of the liver fatty acid-binding protein gene (Fabpl4xat-132). Fabpl4xat-132-mediated Cre expression and recombination resulted in a two-fold decrease in c-MYC protein expression with no effect on intestinal tract morphology. Small intestinal tumorigenesis was significantly suppressed throughout the small intestinal tract of ApcMin/+; c-Mycfl/fl mice compared to c-Myc wild type littermates. In ApcMin/+; c-Mycfl/fl mice, the intestinal apoptosis was higher in the areas of the small intestine with the decreased c-Myc protein expression (P=0.0016, compared to their littermates with the wild type c-Myc). Thus, conditional inactivation of c-Myc, mediated by Fabpl4xat-132-driven Cre-recombinase, suppresses Apc-dependent intestinal tumorigenesis in adult ApcMin/+ mice, without apparent effect on normal intestinal mucosa.

Animals↗
PubMed1996

Three secretory phospholipase A(2) genes that map to human chromosome 1P35-36 are not mutated in individuals with attenuated adenomatous polyposis coli.

Mutation of Pla2g2a, a secretory phospholipase A(2) gene, dramatically increases the number of intestinal polyps that develop in the multiple intestinal neoplasia (Min) mouse, a murine model for adenomatous polyposis coli in humans. We tested the hypothesis that mutation of the human homologue(s) of this gene might be responsible for the more severe phenotype (hundreds of polyps) seen in a subset of individuals with attenuated adenomatous polyposis coli (AAPC). DNA sequence analysis demonstrated that alterations of PLA2G2A, as well as related genes PLA2G2C and PLA2G5, were evenly distributed between three classes of AAPC subjects: those with small, intermediate, and large numbers of adenomatous colonic polyps. Among 67 additional unrelated AAPC subjects, a stop mutation in PLA2G2C did not correlate with an increased burden of adenomatous polyps. Therefore, mutation of the human homologue(s) of murine Pla2g2a does not appear to be responsible for phenotypic variation among subjects with AAPC.

Adenomatous Polyposis Coli↗