Polyposis Coli Multiple Intestinal Neoplasia Research Articles

Preclinical and clinical evidence of the association of colibactin-producing Escherichia coli with anxiety and depression in colon cancer

BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent. The gut microbiota contributes to colorectal carcinogenesis (CRC), as demonstrated with colibactin-producing Escherichia coli (CoPEC). AIM To evaluate the association between CoPEC prevalence and anxiety- and depressive-like behaviors with both preclinical and clinical approaches. METHODS Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric interview. Results were compared according to the CoPEC colonization. In parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC strain. Their behavior was assessed using the Elevated Plus Maze test, the Forced Swimming Test and the Behavior recognition system PhenoTyper®. RESULTS In a limited cohort, all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis, whereas only one patient (17%) without CoPEC did. This result was confirmed in C57BL6/J wild-type mice and in a CRC susceptibility mouse model (adenomatous polyposis colimultiple intestinal neoplasia/+). Mice exhibited a significant increase in anxiety- and depressive-like behaviors after chronic infection with a CoPEC strain. CONCLUSION This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.

Chemopreventive effect of 4'-hydroxychalcone on intestinal tumorigenesis in ApcMin mice.

Chalcones and its derivatives are reported to exhibit anti-cancer effects in several cancer cell lines, including colon cancer cells. However, the in vivo anticancer effects and associated mechanisms of chalcones against intestinal tumorigenesis currently remain unclear. The aim of the present study was to investigate the chemopreventive effect of a chalcone derivative, 4′-hydroxychalcone (4-HC), in a transgenic adenomatous polyposis coli multiple intestinal neoplasia mouse model (ApcMin) of spontaneous intestinal adenomas. ApcMin mice were fed 4-HC (10 mg/kg/day) or the vehicle control by oral gavage starting at 8 weeks of age, and were sacrificed at 20 weeks. The administration of 4-HC significantly decreased the number of colon adenomas by 45% and the size of colon adenomas by 35% compared with the respective controls. Similarly, the number of adenomas in the distal small intestine (DSI) and proximal small intestine also decreased by 35 and 33%, respectively, in 4-HC-treated mice, and adenoma size in the DSI decreased by 39% compared with the respective controls. Treatment with 4-HC strongly decreased proliferation in colon and DSI adenomas, as detected by immunofluorescence staining with the proliferation marker protein Ki-67, and promoted apoptosis in colon adenomas, as detected by TUNEL immunofluorescence staining. In addition, decreased mRNA expression of β-catenin target genes, including c-Myc, Axin2 and CD44, in colon adenomas of 4-HC-treated animals demonstrated the involvement of the Wnt/β-catenin signaling pathway in the initiation and progression of colon neoplasms. Treatment with 4-HC also decreased the protein levels of β-catenin in colon adenomas, as demonstrated by immunofluorescence staining. The results suggested that 4-HC may be a promising candidate for the chemoprevention of intestinal tumorigenesis, and further investigations are required to evaluate its clinical utility.

Silymarin, boswellic acid and curcumin enriched dietetic formulation reduces the growth of inherited intestinal polyps in an animal model.

BACKGROUNDSome substances of plant origin have been reported to exert an effect in reducing intestinal neoplasm development, especially in animal models. Adenomatous polyposis coli multiple intestinal neoplasia - ApcMin/+ is the most studied murine model of genetic intestinal carcinogenesis.AIMTo assess whether an enriched nutritional formulation (silymarin, boswellic acid and curcumin) with proven “in vitro” and “in vivo” anti-carcinogenetic properties may prevent inherited intestinal cancer in animal model.METHODSForty adenomatous polyposis coli multiple intestinal neoplasia - ApcMin/+ mice were used for the study of cancer prevention. They were divided into two groups: 20 assumed standard and 20 enriched diet. At the 110th d animals were sacrificed. In each group, four subgroups received intraperitoneal bromodeoxyuridine injection at different times (24, 48, 72 and 96 h before the sacrifice) in order to assess epithelial turnover. Moreover, we evaluated the following parameters: Intestinal polypoid lesion number and size on autoptic tissue, dysplasia and neoplasia areas by histological examination of the whole small intestine, inflammation by histology and cytokine mRNA expression by real-time polymerase chain reaction, bromodeoxyuridine and TUNEL immuno-fluorescence for epithelial turnover and apoptosis, respectively. Additionally, we performed western blotting analysis for the expression of estrogen alpha and beta receptors, cyclin D1 and cleaved caspase 3 in normal and polypoid tissues.RESULTSCompared to standard, enriched diet reduced the total number (203 vs 416) and the mean ± SD/animal (12.6 ± 5.0 vs 26.0 ± 8.8; P < 0.001) of polypoid lesions. In enriched diet group a reduction in polyp size was observed (P < 0.001). Histological inflammation and pro-inflammatory cytokine expression were similar in both groups. Areas of low-grade dysplasia (P < 0.001) and intestinal carcinoma (IC; P < 0.001) were significantly decreased in enriched diet group. IC was observed in 100% in standard and 85% in enriched formulation assuming animals. Enriched diet showed a faster epithelial migration and an increased apoptosis in normal mucosa and low-grade dysplasia areas (P < 0.001). At western blotting, estrogen receptor beta protein was well expressed in normal mucosa of enriched and standard groups, with a more marked trend associated to the first one. Estrogen receptor alpha was similarly expressed in normal and polypoid mucosa of standard and enriched diet group. Cleaved caspase 3 showed in normal mucosa a stronger signal in enriched than in standard diet. Cyclin D1 was more expressed in standard than enriched diet group of both normal and polypoid tissue.CONCLUSIONOur results are suggestive of a chemo-preventive synergic effect of the components (silymarin, boswellic acid and curcumin) of an enriched formulation in inherited IC. This effect may be mediated by the reduction of epithelial proliferation, the increase of apoptosis and the acceleration of villous cell renewal due to dietary formulation intake.

Modified Shenlingbaizhu decoction reduces intestinal adenoma formation in adenomatous polyposis coli multiple intestinal neoplasia mice by suppression of hypoxia-inducible factor 1α-induced CD4 + CD25+ forkhead box P3 regulatory T cells

OBJECTIVETo test the hypothesis that modified Shenlingbaizhu decoction (MSD) attenuates the formation of intestinal adenomas by regulating activation of CD4+CD25+ forkhead box P3 (FoxP3) regulatory T cells (Tregs) by downregulation of hypoxia-inducible factor 1α (HIF-1α). METHODSChemical fingerprints of ginsenoside Rb1, ginsenoside Rc, paeoniflorin, and dioscin in standard extractions were used as material bases of MSD. Adenomatous polyposis coli multiple intestinal neoplasia (ApcMin/+) mice, which harbor a mutation in adenomatous polyposis coli, were used to host intestinal adenomas. Peripheral blood and spleen Tregs were analyzed by flow cytometry. Protein expression was analyzed by immunohistochemistry and Western blotting. RESULTSThe number and size of intestinal adenomas were significantly reduced by MSD treatment. Mucosal thickening and the spleen size were also substantially decreased by MSD. The carcinogenesis process in ApcMin/+ mice resembled that of human colorectal cancer. Molecular markers of neoplasms, such as β-catenin, cyclooxygenase-2, proliferating cell nuclear antigen, and p53, were substantially ameliorated by MSD treatment. Moreover, MSD downregulated peripheral and spleen CD4 + CD25+FoxP3+Tregs and reduced in situ expression of CD4, CD25, and FoxP3 in intestinal adenomas. MSD also suppressed HIF-1α expression in the intestinal adenomas, and HIF-1α inhibition decreased expression of FoxP3 in Jurkat T cells under hypoxic conditions. CONCLUSIONMSD is a valid prescription to control the formation of intestinal adenomas in ApcMin/+ mice. It exerts anti-cancer effects partially through suppression of HIF-1α that induced activation of CD4+CD25+FoxP3+ Tregs in vivo and in vitro.

Chemoprevention of intestinal tumorigenesis by the natural dietary flavonoid myricetin in APCMin/+ mice.

Myricetin is a natural dietary flavonoid compound. We evaluated the efficacy of myricetin against intestinal tumorigenesis in adenomatous polyposis coli multiple intestinal neoplasia (APCMin/+) mice. Myricetin was given orally once a day for 12 consecutive weeks. APCMin/+ mice fed with myricetin developed fewer and smaller polyps without any adverse effects. Histopathological analysis showed a decreased number of dysplastic cells and degree of dysplasia in each polyp. Immunohistochemical and western blot analysis revealed that myricetin selectively inhibits cell proliferation and induces apoptosis in adenomatous polyps. The effects of myricetin were associated with a modulation the GSK-3β and Wnt/β-catenin pathways. ELISA analysis showed a reduced concentration of pro-inflammatory cytokines IL-6 and PGE2 in blood, which were elevated in APCMin/+ mice. The effect of myricetin treatment was more prominent in the adenomatous polyps originating in the colon. Further studies showed that myricetin downregulates the phosphorylated p38 MAPK/Akt/mTOR signaling pathways, which may be the mechanisms for the inhibition of adenomatous polyps by myricetin. Taken together, our data show that myricetin inhibits intestinal tumorigenesis through a collection of biological activities. Given these results, we suggest that myricetin could be used preventatively to reduce the risk of developing colon cancers.

Naringin, a natural dietary compound, prevents intestinal tumorigenesis in Apc (Min/+) mouse model.

Naringin is a natural dietary flavonoid compound. We aimed to evaluate the effects of naringin on intestinal tumorigenesis in the adenomatous polyposis coli multiple intestinal neoplasia (Apc (Min/+)) mouse model. Apc (Min/+) mice were given either naringin (150 mg/kg) or vehicle by p.o. gavage daily for 12 consecutive weeks. Mice were killed with ether, and blood samples were collected to assess the concentrations of IL-6 and PGE2. Total intestines were removed, and the number of polyps was examined. Tissue samples of intestinal polyps were subjected to the assays of histopathology, immunohistochemical analysis and Western blotting analysis. Apc (Min/+) mice fed with naringin developed less and smaller polyps in total intestines. Naringin prevented intestinal tumorigenesis without adverse effects. Histopathologic analysis revealed the reduction of dysplastic cells and dysplasia in the adenomatous polyps. The treatments' effects might arise from its anti-proliferation, induction of apoptosis and modulation of GSK-3β and APC/β-catenin signaling pathways. Naringin also exerted its effects on tumorigenesis through anti-chronic inflammation. Naringin prevented intestinal tumorigenesis likely through a collection of activities including anti-proliferation, induction of apoptosis, modulation of GSK-3β and APC/β-catenin pathways and anti-inflammation. Naringin is a potential chemopreventive agent for reducing the risk of colonic cancers.

Chemoprevention of intestinal adenomatous polyposis by acetyl‐11‐keto‐beta‐boswellic acid in APCMin/+ mice

Acetyl-11-keto-beta-boswellic acid (AKBA) is a derivative of boswellic acid, which is an active component of the gum resin of Boswellia serrata. AKBA has been used as an adjuvant medication for treatment of inflammatory diseases. In this study, we aimed to evaluate the efficacy of AKBA as a chemopreventive agent against intestinal adenomatous polyposis in the adenomatous polyposis coli multiple intestinal neoplasia (APC(Min/+) ) mouse model. APC(Min/+) mice were administered AKBA by p.o. gavage for 8 consecutive weeks. The mice were sacrificed and the number, size and histopathology of intestinal polyps were examined by light microscopy. AKBA decreased polyp numbers by 48.9% in the small intestine and 60.4% in the colon. An even greater AKBA effect was observed in preventing the malignant progression of these polyps. The number of large (>3 cm) colonic polyposis was reduced by 77.8%. Histopathologic analysis demonstrated a significant reduction in the number of dysplastic cells and in the degree of dysplasia in each polyp after AKBA treatment. There was no evidence of high grade dysplasia or intramucosal carcinoma in any of the polyps examined within the treated group. More interestingly, interdigitated normal appearing intestinal villi were observed in the polyps of the treated group. During the course of the study, AKBA was well tolerated by the mice with no obvious signs of toxicity. Results from immunohistochemical staining, Western blotting and enzyme-linked immunosorbent assay indicated that the chemopreventive effect of AKBA was attributed to a collection of activities including antiproliferation, apoptosis induction, antiangiogenesis and anti-inflammation. AKBA was found to exert its chemopreventive action through the inhibition of the Wnt/β-catenin and NF-κB/cyclooxygenase-2 signaling pathways. Our findings suggest that AKBA could be a promising regimen in chemoprevention against intestinal tumorigenesis.

Mitochondrial Genome Instability and ROS Enhance Intestinal Tumorigenesis in APC Min/+ Mice

Alterations in mitochondrial oxidative phosphorylation have long been documented in tumors. Other types of mitochondrial dysfunction, including altered reactive oxygen species (ROS) production and apoptosis, also can contribute to tumorigenesis and cancer phenotypes. Furthermore, mutation and altered amounts of mitochondrial DNA (mtDNA) have been observed in cancer cells. However, how mtDNA instability per se contributes to cancer remains largely undetermined. Mitochondrial transcription factor A (TFAM) is required for expression and maintenance of mtDNA. Tfam heterozygous knock-out (Tfam(+/-)) mice show mild mtDNA depletion, but have no overt phenotypes. We show that Tfam(+/-) mouse cells and tissues not only possess less mtDNA but also increased oxidative mtDNA damage. Crossing Tfam(+/-) mice to the adenomatous polyposis coli multiple intestinal neoplasia (APC(Min/+)) mouse cancer model revealed that mtDNA instability increases tumor number and growth in the small intestine. This was not a result of enhancement of Wnt/β-catenin signaling, but rather appears to involve a propensity for increased mitochondrial ROS production. Direct involvement of mitochondrial ROS in intestinal tumorigenesis was shown by crossing APC(Min/+) mice to those that have catalase targeted to mitochondria, which resulted in a significant reduction in tumorigenesis in the colon. Thus, mitochondrial genome instability and ROS enhance intestinal tumorigenesis and Tfam(+/-) mice are a relevant model to address the role of mtDNA instability in disease states in which mitochondrial dysfunction is implicated, such as cancer, neurodegeneration, and aging.

Resistant carbohydrates stimulate cell proliferation and crypt fission in wild-type mice and in theApcMin/+mouse model of intestinal cancer, association with enhanced polyp development

Fermentation of carbohydrates in the colon can stimulate cell proliferation and could thus be a cancer risk. The effects of resistant carbohydrates, i.e. those not digested and absorbed in the small intestine, on cell proliferation, crypt fission and polyp development were investigated in wild-type and adenomatous polyposis coli multiple intestinal neoplasia (Apc(Min/+)) mice. Fifteen 4-week-old female wild-type and fifteen Apc(Min/+) mice were used for each group and fed a chow diet, a semi-synthetic diet or the semi-synthetic supplemented with wheat bran or an apple pomace preparation, both high in resistant carbohydrates, for 8 weeks. Tissue from all mice was used to measure cell proliferation and crypt fission and tissue from the Apc(Min/+) mice was scored for polyp number and tumour burden. There were slight reductions in intestinal mass in the mice fed the semi-synthetic diets and this was increased by the inclusion of resistant carbohydrates. The Apc(Min/+) mice had elevated cell proliferation and crypt fission in the distal small intestine and colon and these were increased by the resistant carbohydrates. Bran or apple pomace significantly increased polyp number in the proximal third of the small intestine. Apple pulp more than doubled polyp number throughout the small bowel (99.2 (SEM 11.1) v. 40.0 (SEM 8.2), P<0.004). Bran and apple pomace increased polyp diameter and hence burden in the colon by 243 and 150 %, respectively (P<0.05). In conclusion, both types of resistant carbohydrates increased polyp number and tumour burden and this was associated with elevated epithelial cell proliferation and crypt fission.

The Wnt/β-catenin signaling pathway targets PPARγ activity in colon cancer cells

Control of colon cell fate in adenocarcinomas is disrupted, in part, due to aberrant Wnt/β-catenin signaling. The nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) has been implicated in the development of colon cancers. In the adenomatous polyposis coli multiple intestinal neoplasia (APCMin) mouse cancer model, PPARγ expression in the colonic mucosa is markedly altered. In addition, PPARγ protein levels are elevated, possibly through sequestration by activated β-catenin in colon cancer cell lines. Induction of the Wnt/β-catenin pathway by LiCl also elevated PPARγ levels and induced PPARγ-dependent reporter and endogenous target genes. Mechanistically, PPARγ, through interactions with β-catenin and T cell transcription factor (Tcf)-4, may be a determinant of cell fate and is likely a target of the Wnt pathway in cancer cells.

Chemopreventive activity of crude hydroxsymatairesinol (HMR) extract in Apc Min mice

We studied the effects of a lignan, hydroxymatairesinol (HMR), and rye bran on intestinal tumor development in adenomatous polyposis colimultiple intestinal neoplasia (Apc) Min mice. HMR showed a strong chemopreventive effect in this animal model. The mean number of adenomas in the small intestine was significantly lower (26.6±11.0, P<0.05) in mice fed the inulin and HMR when compared with the inulin and inulin/rye bran fed mice (39.6±8.9 and 36.0±7.4, respectively). HMR resulted in normalization of β-catenin levels in adenoma tissue, indicating that HMR mediates its chemopreventive effect through the Apc-β-catenin pathway. In the cytosolic fraction, β-catenin level in adenoma tissue was significantly elevated ( P=0.008–0.013) in all the diet groups as compared with that of the surrounding mucosa. In the nuclear fraction, β-catenin in the inulin (3.15±2.9 relative units) and inulin/rye (5.17±6.94 relative units) groups was also significantly higher ( P=0.003–0.009) in the adenoma tissue when compared with the surrounding mucosa (0.5±0.5 and 0.35±0.39 relative units). However, HMR was able to restore nuclear β-catenin level of the adenoma tissue (0.41±0.25 relative units) to the level found in the surrounding mucosa (0.36±0.28 relative units).

Chemopreventive activity of hydroksymatairesinol in adenomatous polyposis colimultiple intestinal neoplasia (Apc) Min mice

We studied the effects of a lignan, hydroxymatairesinol (HMR), and rye bran on intestinal tumor development in adenomatous polyposis colimultiple intestinal neoplasia (Apc) Min mice. HMR showed a strong chemopreventive effect in this animal model. The mean number of adenomas in the small intestine was significantly lower (26.6±11.0, P<0.05) in mice fed the TNS tumor promoter insulin and HMR when compared with the insulin and insulin/rye bran fed mice (39.6±8.9 and 36.0±7.4, respectively). HMR resulted in normalization of β-catenin levels in adenoma tissue, indicating that HMR mediates its chemopreventive effect through the Apc-β-catenin pathway. In the cytosolic fraction, β-catenin level in adenoma tissue was significantly elevated ( P=0.008–0.013) in all the diet groups as compared with that of the surrounding mucosa. In the nuclear fraction, β-catenin in the insulin (3.15±2.9 relative units) and insulin/rye (5.17±6.94 relative units) groups was also significantly higher ( P=0.003–0.009) in the adenoma tissue when compared with the surrounding mucosa (0.5±0.5 and 0.35±0.39 relative units). However, HMR was able to restore nuclear β-catenin level of the adenoma tissue (0.41±0.25 relative units) to the level found in the surrounding mucosa (0.36±0.28 relative units).