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    We have recently shown that American ginseng (AG) prevents and treats mouse colitis. Because both mice and humans with chronic colitis have a high colon cancer risk, we tested the hypothesis that AG can be used to prevent colitis-driven colon cancer. Using the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model of ulcerative colitis, we show that AG can suppress colon cancer associated with colitis. To explore the molecular mechanisms of the anticancer effects of AG, we also carried out antibody array experiments on colon cells isolated at a precancerous stage. We found there were 82 protein end points that were either significantly higher (41 proteins) or significantly lower (41 proteins) in the AOM + DSS group compared with the AOM-alone (control) group. In contrast, there were only 19 protein end points that were either significantly higher (10 proteins) or significantly lower (9 proteins) in the AOM + DSS + AG group compared with the AOM-alone (control) group. Overall, these results suggest that AG keeps the colon environment in metabolic equilibrium when mice are treated with AOM + DSS and gives insight into the mechanisms by which AG protects from colon cancer associated with colitis.
    Citations (35)
    The authors recently reported that transgenic mice (hGAS) expressing pharmacologic levels of progastrin (PG) (> 10 nM to 100 nM) exhibited increased susceptibility to colon carcinogenesis in response to azoxymethane (AOM). It is not known whether PG functions as a cocarcinogen at the concentrations observed in patients with hypergastrinemia (approximately 1.0 nM).The authors generated transgenic mice that overexpressed either wild-type (wtPG) or mutant (mtPG) human PG in the intestinal mucosa using the murine fatty acid binding protein (Fabp) promoter. Fabp-PG mice and their wild-type littermates were treated with AOM, and their colons were examined for preneoplastic (aberrant crypt foci [ACF]) and neoplastic (adenomas [Ads] and adenocarcinomas [AdCas]) lesions after 2 weeks and 6 months of treatment.ACF and tumors were significantly more common (by a factor of approximately 2) in colon specimens from both Fabp-wtPG mice and Fabp-mtPG mice relative to wild-type mice. It is noteworthy that the multiplicity of ACF and the total number of small and large Ads and AdCas were significantly greater in colon specimens from Fabp-PG mice compared with colon specimens from wild-type mice, irrespective of gender.The results of the current study suggest that at concentrations (approximately 1.0 nM) far lower than the ones observed in hGAS mice, PG functions as an equally potent cocarcinogen and significantly increases the risk of colon carcinogenesis in response to AOM. Thus, PG may represent a clinically relevant target molecule in patients with hypergastrinemia or colon carcinoma.
    Aberrant crypt foci
    Wild type
    Knockout mouse
    Ratón
    Citations (49)
    Colorectal cancer is one of the most common and lethal cancers in the world. An important causative factor of colorectal cancer is ulcerative colitis. In this study, we investigated the therapeutic effects of piperlongumine (PL) on the dextran sulfate sodium (DSS)-induced acute colitis and azoxymethane (AOM)/DSS-induced colorectal cancer mouse models. Our results showed that PL could inhibit the inflammation of DSS-induced mouse colitis and reduce the number of large neoplasms (diameter >2 mm) of AOM/DSS-induced mouse colorectal cancer by downregulation of proinflammatory cytokines cyclooxygenase-2 and interleukin-6 and epithelial-mesenchymal transition-related factors, β-catenin, and snail expressions, but fail to improve the colitis symptoms and to decrease the incidence of colonic neoplasms and the number of small neoplasms (diameter <2 mm). These data suggested that PL might be an effective agent in treating colitis and colorectal cancer.
    Proinflammatory cytokine
    Citations (13)
    To investigate the changes of miR-155 and its target genes in colitis-associated carcinogenesis.Colitis-associated colon cancer was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in C57BL/6 mice. Mice of three different stages during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment and a DSS only group representing chronic inflammation without cancer were set up as well. Colon tissue was collected and expression of miR-155 in the colon tissues was measured by real-time fluorescent quantitative PCR. TargetScan and PicTar were used to predict potential target genes of miR-155, which were then preliminarily screened with our gene expression microarray database of AOM-DSS mouse model. Regular PCR was used to confirm the changes of the expression of these potential target genes in AOM-DSS mouse model.Colitis-associated colon cancer was effectively induced by azoxymethane and dextran sulfate sodium in C57BL/6 mice. Histological examination revealed that the evolution process was sequentially from normal, mild dysplasia, moderate dysplasia, and severe dysplasia to adenocarcinoma in the AOM-DSS mouse model. The level of miR-155 was gradually elevated with the formation of colitis-associated colon cancer. There was no significant difference between the levels of miR-155 expression in the DSS group (0.005 6 ± 0.003 7) and control group (0.012 0 ± 0.005 1) (P > 0.05), but the level of miR-155 in the AD3 group (0.054 4 ± 0.027 0) was significantly higher than that of the DSS group (0.005 6 ± 0.003 7)(P < 0.01). No significant change of miR-155 expression was found in the DSS only group. The relative expression levels of miR-155 in the control group, DSS only group and AD3 group were 0.012 0 ± 0.005 1, 0.005 6 ± 0.003 7, 0.054 4 ± 0.027 0, respectively. Data analysis with the gene expression microarray showed that Tle4, Kcna1, Itk, Bcorl1, Cacna1c, Rspo2 and Foxo3 were potential target genes of miR-155 in the AOM-DSS mouse model. Changes of Kcna1 and Cacna1c in the AOM-DSS mouse model were validated to be consistent with the changes obtained with the gene expression microarray.The up-regulation of miR-155 is related to colitis-associated carcinogenesis, but is irrelevant to chronic inflammation in the mouse model.
    miR-155
    Citations (5)
    Vitamin A is essential to mucosal immunity and cell differentiation. The fact that lack of it might involve chronic inflammation and increased risk of cancer has been reported. Little is known about the mechanism of vitamin A deficiency in the development of colitis and its influence on development of colorectal cancer. To determine the influence of vitamin A deficiency on colitis and colorectal cancer development, an experimental study using a colitis mouse model was performed. Dextran sulfate sodium (DSS) colitis was induced in vitamin A-deficient and vitamin A-supplemented mice. Further, colorectal carcinoma was induced by a combination of azoxymethane preinjection and DSS colitis. Results were compared between the two groups mainly by immunohistochemical analysis. Colitis was more severe and recovery from colitis was slower in vitamin A-deficient mice than in vitamin A-supplemented mice. Compared with vitamin A-supplemented mice, vitamin A-deficient mice had decreases in colonic subepithelial myofibroblasts and the ratio of mucosal IgA + /IgG + cells, increases in CD11c + dendritic cells, and a higher rate of development of colorectal carcinoma with colitis following azoxymethane. Vitamin A lipid droplets in subepithelial myofibroblasts were decreased in vitamin A-deficient mice, suggesting alterations in colonic crypt niche function. Thus, vitamin A inhibited colitis and the development of colorectal cancer.
    Citations (45)
    Animal models of experimentally induced inflammatory bowel disease (IBD) are useful for understanding more about the mechanistic basis of disease, identifying new targets for therapeutic intervention, and testing novel therapeutic agents. This unit provides detailed protocols for four of the most commonly used mouse models of experimentally induced intestinal inflammation: chemical induction of colitis by dextran sodium sulfate (DSS), hapten-induced colitis via 2,4,6-trinitrobenzene sulfonic acid (TNBS), Helicobacter-induced colitis in mdr1a(-/-) mice, and the CD4(+) CD45RB(hi) SCID transfer colitis model.
    Shikonin (Shk) inhibits the development of colorectal dysplasia and the colitis induced in a mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS), as demonstrated both by macroscopic and biochemical determinations. The oral administration of shikonin prevents weight loss and colorectum shortening. Histological analysis revealed a decrease both in the severity and extent of inflammation, together with an amelioration of the colonic architecture and the protection from the appearance of dysplasia. This was associated reduction in MPO activity together with the inhibition of COX-2 and iNOS expression. A possible mechanism of action which would be responsible for this protection is the inhibition of NF-κB activation, since we demonstrated the inhibition of the translocation of NF-κB-p65 subunit to the nucleus in the colon homogenate. As a positive control we examined the effect of oral administration of sulfasalazine (Ssz).
    Sulfasalazine
    Citations (0)
    Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the intestinal tract and is primarily comprised of Crohn's disease (CD) and ulcerative colitis (UC). Several murine models that include both chemical induced and genetic models have been developed that mimic some aspects of either CD or UC. These models have been instrumental in our understanding of IBD. Of the chemical induced colitis models, dextran sodium sulfate (DSS) induced colitis model is a relatively simple and very widely used model of experimental colitis.
    Inflammatory Bowel Diseases
    genetic model
    Citations (14)
    Animal models of experimentally induced inflammatory bowel disease (IBD) are useful for understanding more about the mechanistic basis of the disease, identifying new targets for therapeutic intervention, and testing novel therapeutics. This unit provides detailed protocols for five widely used mouse models of experimentally induced intestinal inflammation: chemical induction of colitis by dextran sodium sulfate (DSS), hapten-induced colitis via 2,4,6-trinitrobenzene sulfonic acid (TNBS), Helicobacter-induced colitis in mdr1a(-/-) mice, the CD4(+) CD45RB(hi) SCID transfer colitis model, and the IL-10(-/-) colitis model. © 2016 by John Wiley & Sons, Inc.
    Inflammatory Bowel Diseases