• BMB Reports
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• 제55권12호
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• pp.609-614
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• 2022

Mutation of the gene for adenomatous polyposis coli (APC), as seen in Apc^Min/+ mice, leads to intestinal adenomas and carcinomas via stabilization of β-catenin. Transmembrane 4 L six family member 5 (TM4SF5) is involved in the development of non-alcoholic fatty liver disease, fibrosis, and cancer. However, the functional linkage between TM4SF5 and APC or β-catenin has not been investigated for pathological outcomes. After interbreeding Apc^Min/+ with TM4SF5-overexpressing transgenic (Tg^TM4SF5) mice, we explored pathological outcomes in the intestines and livers of the offspring. The intestines of 26-week-old dual-transgenic mice (Apc^Min/+:Tg^TM4SF5) had intramucosal adenocarcinomas beyond the single-crypt adenomas in Apc^Min/+ mice. Additional TM4SF5 overexpression increased the stabilization of β-catenin via reduced glycogen synthase kinase 3β (GSK3β) phosphorylation on Ser9. Additionally, the livers of the dualtransgenic mice showed distinct sinusoidal dilatation and features of hepatic portal hypertension associated with fibrosis, more than did the relatively normal livers in Apc^Min/+ mice. Interestingly, TM4SF5 overexpression in the liver was positively linked to increased GSK3β phosphorylation (opposite to that seen in the colon), β-catenin level, and extracellular matrix (ECM) protein expression, indicating fibrotic phenotypes. Consistent with these results, 78-week-old Tg^TM4SF5 mice similarly had sinusoidal dilatation, immune cell infiltration, and fibrosis. Altogether, systemic overexpression of TM4SF5 aggravates pathological abnormalities in both the colon and the liver.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1115-1118
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• 2012

Diallyl sulfide (DAS), a flavoring compound derived from garlic, is considered to have cancer chemopreventive potential in experimental animals and humans. This study was designated to examine possible chemopreventive effects of DAS on colon carcinogenesis using genetically engineered transgenic $Apc^{Min/+}$ mice, a well-established animal model for familial adenomatous polyposis (FAP) and sporadic colorectal cancer. Male C57BL/6J-$Apc^{Min/+}$ mice were divided into three groups. Animals of group 1 were placed on the basal diet (AIN-76A) as non-treated controls. Animals of groups 2 and 3 were given DAS-containing diets (in doses of 100 and 300 ppm, respectively). All mice were sacrificed at the end of week 10 of the experiment. Histopathological investigation revealed that the incidence of colonic polyps was decreased dose-dependently by 19% (13/16) in group 2 and by 32% (13/20) in group 3 compared to the 100% incidence (10/10) in group 1. The multiplicity of colonic polyps per mouse was also slightly decreased by DAS treatment ($1.88{\pm}0.35$ in group 2 and $1.63{\pm}0.36$ in group 3) compared to $2.00{\pm}0.39$ in group 1. On the other hand, there were no significant differences in the numbers of total polyps per mouse in the small intestine between the groups. Taken together, we suggest that DAS may exert promising inhibitory effects on colon carcinogenesis in the transgenic $Apc^{Min/+}$ mice.

• Nutrition Research and Practice
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• 제6권5호
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• pp.396-404
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• 2012

The aim of the study was to investigate the inhibitory effects of calcium against intestinal cancer in vitro and in vivo. We first investigated the effects of calcium treatment in HCT116 and HT29 human colon cancer cells. At the concentration range of 0.8-2.4 mM, calcium significantly inhibited cell growth (by 9-29%), attachment (by 12-26%), invasion (by 15-31%), and migration (by 19-61%). An immunofluorescence microscope analysis showed that the treatment with calcium (1.6 mM) for 24 h increased plasma membrane ${\beta}$-catenin but decreased nuclear ${\beta}$-catenin levels in HT29 cells. We then investigated the effect of dietary calcium on intestinal tumorigenesis in $Apc^{Min/+}$ mice. Mice received dietary treatment starting at 6 weeks of age for the consecutive 8 weeks. The basal control diet contained high-fat (20% mixed lipids by weight) and low-calcium (1.4 mg/g diet) to mimic the average Western diet, while the treatment diet contained an enriched level of calcium (5.2 mg calcium/g diet). The dietary calcium treatment decreased the total number of small intestinal tumors (by 31.4%; P < 0.05). The largest decrease was in tumors which were ${\geq}$ 2 mm in diameter, showing a 75.6% inhibition in the small intestinal tumor multiplicity (P < 0.001). Immunohistochemical analysis showed significantly reduced nuclear staining of ${\beta}$-catenin (expressed as nuclear positivity), but increased plasma membrane staining of ${\beta}$-catenin, in the adenomas from the calcium-treated groups in comparison to those from the control group (P < 0.001). These results demonstrate intestinal cancer inhibitory effects of calcium both in human colon cancer cells and $Apc^{Min/+}$ mice. The decreased ${\beta}$-catenin nuclear localization caused by the calcium treatment may contribute to the inhibitory action.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5587-5592
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• 2014

Aloe-emodin (AE), a natural anthraquinone compound, has been reported to exhibit anticancer activity in various cancer cell lines and anti-inflammatory effects in murine macrophages. In the present study, we investigated the cancer chemopreventive effects of AE in an Apc-deficient Min mouse model. In the first experiment, male Min mice were fed a basal diet or diets containing 5 ppm AE and 10 ppm AE for 12 weeks. The dietary administration of 5 ppm AE significantly reduced the number of colorectal tumors. In a second experiment, we investigated the effects of AE on colitis-related colon carcinogenesis in Min mouse treated with dextran sodium sulfate (DSS). Female Min mice were administered 1% DSS in their drinking water for 7 days. AE was given to mice in their diet at a dose of 5 or 50 ppm for 5 weeks. Feeding with AE significantly reduced the number of colorectal tumors. When proliferation of cells in normal-appearing colonic mucosa was assessed by monoclonal anti-rat Ki-67 antibody (MIB-5) immunohistochemistry in experiments 1 and 2, the AE treatment significantly decreased the mean MIB-5-labeling index. These results suggest that the dietary administration of low-dose AE may have chemopreventive effects against development of colorectal tumors in Min mice, possibly in part by reducing cell proliferation in colorectal mucosa.

• BMB Reports
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• 제36권1호
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• pp.35-42
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• 2003

Heterocyclic amines (HCAs) are potent mutagens generated during the cooking of meat and fish, and several of these compounds produce tumors in conventional experimental animals. During the past 5 years or so, HCAs have been tested in a number of novel in vivo murine models, including the following: lacZ, lacI, cII, c-myc/lacZ, rpsL, and $gpt{\Delta}$ transgenics, $XPA^{-/-}$, $XPC^{-/-}$, $Msh2^{+/-}$, $Msh2^{-/-}$ and $p53^{+/-}$ knock-outs, Apc mutant mice ($Apc^{{\Delta}716}$, $Apc^{1638N}$, $Apc^{min}$), and $A33^{{\Delta}N{\beta}-cat}$ knock-in mice. Several of these models have provided insights into the mutation spectra induced in vivo by HCAs in target and non-target organs for tumorigenesis, as well as demonstrating enhanced susceptibility to HCA-induced tumors and preneoplastic lesions. This review describes several of the more recent reports in which novel animal models were used to examine HCA-induced mutagenesis and carcinogenesis in vivo, including a number of studies which assessed the inhibitory activities of chemopreventive agents such as 1,2-dithiole-3-thione, conjugated linoleic acids, tea, curcumin, chlorophyllin-chitosan, and sulindac.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4435-4440
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• 2013

Aloe vera gel supercritical $CO_2$ extract (AVGE) has been shown to contain five phytosterols, reduce visceral fat accumulation, and influence the metabolism of glucose and lipids in animal model experiments. Recent epidemiologic studies have shown that obesity is an established risk factor for several cancers including colorectal cancer. Therefore, we examined the effects of AVGE on intestinal polyp formation in Apc-deficient Min mice fed a high-fat diet. Male Min mice were divided into normal diet (ND), high fat diet (HFD), low dose AVGE (HFD+LAVGE) and high dose AVGE (HFD+HAVGE) groups. The ND group received AIN-93G diet and the latter 3 groups were given modified high-fat AIN-93G diet (HFD) for 7 weeks. AVGE was suspended in 0.5% carboxymethyl cellulose (CMC) and administered orally to mice in HFD+LAVGE and HFD+HAVGE groups every day (except on Sunday) for 7 weeks at a dose of 3.75 and 12.5 mg/kg body weight, respectively. ND and HFD groups received 0.5% CMC alone. Between weeks 4 and 7, body weights in the HFD and HFD+LAVGE groups were reduced more than those in the ND group. However, body weights were not reduced in the HFD+HAVGE group. Mice were sacrificed at the end of the experiment and their intestines were scored for polyps. No significant differences were observed in either the incidence and multiplicity of intestinal polyps (${\geq}0.5$ mm in a diameter) among the three groups fed HFD. However, when intestinal polyps were categorized by their size into 0.5-1.4, 1.5-2.4, or ${\geq}2.5$ mm, the incidence and multiplicity of large polyps (${\geq}2.5$ mm) in the intestine in the HFD+HAVGE group were significantly lower than those in the HFD group. We measured plasma lipid (triglycerides and total cholesterol) and adipocytokine [interleukin-6 and high molecular weight (HMW) adiponectin] levels as possible indicators of mechanisms of inhibition. The results showed that HMW adiponectin levels in the HFD group were significantly lower than those in the ND group. However, the levels in the HFD+HAVGE group were significantly higher than those in the HFD group. These results indicate that HAVGE reduced large-sized intestinal polyps and ameliorated reduction in plasma HMW adiponectin levels in Min mice fed HFD.

• Journal of Ginseng Research
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• 제39권3호
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• pp.230-237
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• 2015

Background: Colorectal cancer (CRC) is a leading cause of death worldwide. Chronic gut inflammation is recognized as a risk factor for tumor development, including CRC. American ginseng is a very commonly used ginseng species in the West. Methods: A genetically engineered $Apc^{Min/+}$ mouse model was used in this study. We analyzed the saponin composition of American ginseng used in this project, and evaluated its effects on the progression of high-fat-diet-enhanced CRC carcinogenesis. Results: After oral ginseng administration (10-20 mg/kg/d for up to 32 wk), experimental data showed that, compared with the untreated mice, ginseng very significantly reduced tumor initiation and progression in both the small intestine (including the proximal end, middle end, and distal end) and the colon (all p < 0.01). This tumor number reduction was more obvious in those mice treated with a low dose of ginseng. The tumor multiplicity data were supported by body weight changes and gut tissue histology examinations. In addition, quantitative real-time polymerase chain reaction analysis showed that compared with the untreated group, ginseng very significantly reduced the gene expression of inflammatory cytokines, including interleukin-$1{\alpha}$ (IL-$1{\alpha}$), IL-$1{\beta}$, IL-6, tumor necrosis factor-${\alpha}$, granulocyte-colony stimulating factor, and granulocyte-macrophage colony-stimulating factor in both the small intestine and the colon (all p < 0.01). Conclusion: Further studies are needed to link our observed effects to the actions of the gut microbiome in converting the parent ginsenosides to bioactive ginseng metabolites. Our data suggest that American ginseng may have potential value in CRC chemoprevention.

• Journal of Cancer Prevention
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• 제21권2호
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• pp.95-103
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• 2016

Background: Excess energy supply induces chronic low-grade inflammation in association with oxidative stress in various tissues including intestinal epithelium. The objective of this study was to investigate the effect of high-fat diet (HFD) on intestinal cell membrane integrity and intestinal tumorigenesis in $Apc^{Min/+}$ mice. Methods: Mice were fed with either normal diet (ND) or HFD for 12 weeks. The number of intestinal tumors were counted and biomarkers of endotoxemia, oxidative stress, and inflammation were determined. Changes in intestinal integrity was measured by fluorescein isothiocyanate (FITC)-dextran penetration and membrane gap junction protein expression. Results: HFD group had significantly higher number of tumors compared to ND group (P < 0.05). Blood total antioxidant capacity was lower in HFD group, while colonic 8-hydroxy-2'-deoxyguanosine level, a marker of oxidative damage, was higher in HFD group compared to that of ND group (P < 0.05). The penetration of FITC-dextran was substantially increased in HFD group (P < 0.05) while the expressions of membrane gap junction proteins including zonula occludens-1, claudin-1, and occludin were lower in HFD group (P < 0.05) compared to those in ND group. Serum concentration of lipopolysaccharide (LPS) receptor (CD14) and colonic toll-like receptor 4 (a LPS receptor) mRNA expression were significantly higher in HFD group than in ND group (P < 0.05), suggesting that significant endotoxemia may occur in HFD group due to the increased membrane permeability. Serum interleukin-6 concentration and myeloperoxidase activity were also higher in HFD group compared to those of ND group (P < 0.05). Conclusions: HFD increases oxidative stress disrupting intestinal gap junction proteins, thereby accelerating membrane permeability endotoxemia, inflammation, and intestinal tumorigenesis.

• BMB Reports
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• 제39권6호
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• pp.649-655
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• 2006

The NSAID activated gene (NAG-1), a member of the TGF-$\beta$ superfamily, is involved in tumor progression and development. The over-expression of NAG-1 in cancer cells results in growth arrest and increase in apoptosis, suggesting that NAG-1 has anti-tumorigenic activity. This conclusion is further supported by results of experiments with transgenic mice that ubiquitously express human NAG-1. These transgenic mice are resistant to the development of intestinal tumors following treatment with azoxymethane or by introduction of a mutant APC gene. In contrast, other data suggest a pro-tumorigenic role for NAG-1, for example, high expression of NAG-1 is frequently observed in tumors. NAG-1 may be like other members of the TGF-$\beta$ superfamily, acting as a tumor suppressor in the early stages, but acting pro-tumorigenic at the later stages of tumor progression. The expression of NAG-1 can be increased by treatment with drugs and chemicals documented to prevent tumor formation and development. Most notable is the increase in NAG-1 expression by the inhibitors of cyclooxygenases that prevent human colorectal cancer development. The regulation of NAG-1 is complex, but these agents act through either p53 or EGR-1 related pathways. In addition, an increase in NAG-1 is observed in inhibition of the AKT/GSK-$3{\beta}$ pathway, suggesting NAG-1 alters cell survival. Thus, NAG-1 expression is regulated by tumor suppressor pathways and appears to modulate tumor progression.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.683-687
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• 2015

Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.