Chronic intestinal inflammation significantly contributes to the development of colorectal cancer and remains a pertinent clinical challenge, necessitating novel therapeutic approaches. Indole-based microbial metabolite mimics Felix Kopp Kortagere 6 (FKK6), which is a ligand and agonist of the pregnane X receptor (PXR), was recently demonstrated to have PXR-dependent anti-inflammatory and protective effects in a mouse model of dextran sodium sulfate (DSS)-induced acute colitis. Here, we examined the therapeutic potential of FKK6 in a mouse model (C57BL/6 FVB humanized PXR mice) of colitis-associated colon cancer (CAC) induced by azoxymethane and DSS. FKK6 (2 mg/kg) displayed substantial antitumor activity, as revealed by reduced size and number of colon tumors, improved colon histopathology, and decreased expression of tumor markers (c-MYC, β-catenin, Ki-67, and cyclin D) in the colon. In addition, we carried out a chronic toxicity (30 days) assessment of FKK6 (1 mg/kg and 2 mg/kg) in C57BL/6 mice. Histological examination of tissues, biochemical blood analyses, and immunohistochemical staining for Ki-67 and γ-H2AX showed no difference between FKK6-treated and control mice. Comparative metabolomic analyses in mice exposed for 5 days to DSS and administered with FKK6 (0.4 mg/kg) revealed no significant effects on several classes of metabolites in the mouse fecal metabolome. Ames and micronucleus tests showed no genotoxic and mutagenic potential of FKK6 in vitro. In conclusion, anticancer effects of FKK6 in azoxymethane/DSS-induced CAC, together with FKK6 safety data from in vitro tests and in vivo chronic toxicity study, and comparative metabolomic study, are supportive of the potential therapeutic use of FKK6 in the treatment of CAC. SIGNIFICANCE STATEMENT: Microbial metabolite mimicry proposes that chemical mimics of microbial metabolites that serve to protect hosts against aberrant inflammation in the gut could serve as a new paradigm for the development of drugs targeting inflammatory bowel disease if, like the parent metabolite, is devoid of toxicity but more potent against the microbial metabolite receptor. We identified a chemical mimic of Felix Kopp Kortagere 6, and we propose that Felix Kopp Kortagere 6 is devoid of toxicity yet significantly reduces tumor formation in an azoxymethane-dextran sodium sulfate model of murine colitis-induced colon cancer.

• MeSH
• azoxymethan toxicita   MeSH
• chronická nemoc MeSH
• indoly farmakologie   terapeutické užití   MeSH
• kolitida farmakoterapie   chemicky indukované   metabolismus   patologie   MeSH
• kolorektální nádory * farmakoterapie   metabolismus   patologie   MeSH
• modely nemocí na zvířatech * MeSH
• molekulární mimikry MeSH
• myši inbrední C57BL * MeSH
• myši MeSH
• nádory asociované s kolitidou patologie   farmakoterapie   metabolismus   MeSH
• síran dextranu toxicita   MeSH
• zánět farmakoterapie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND & AIMS: Chromosomal instability (CIN) is a carcinogenesis event that promotes metastasis and resistance to therapy by unclear mechanisms. Expression of the colon cancer-associated transcript 2 gene (CCAT2), which encodes a long noncoding RNA (lncRNA), associates with CIN, but little is known about how CCAT2 lncRNA regulates this cancer enabling characteristic. METHODS: We performed cytogenetic analysis of colorectal cancer (CRC) cell lines (HCT116, KM12C/SM, and HT29) overexpressing CCAT2 and colon organoids from C57BL/6N mice with the CCAT2 transgene and without (controls). CRC cells were also analyzed by immunofluorescence microscopy, γ-H2AX, and senescence assays. CCAT2 transgene and control mice were given azoxymethane and dextran sulfate sodium to induce colon tumors. We performed gene expression array and mass spectrometry to detect downstream targets of CCAT2 lncRNA. We characterized interactions between CCAT2 with downstream proteins using MS2 pull-down, RNA immunoprecipitation, and selective 2'-hydroxyl acylation analyzed by primer extension analyses. Downstream proteins were overexpressed in CRC cells and analyzed for CIN. Gene expression levels were measured in CRC and non-tumor tissues from 5 cohorts, comprising more than 900 patients. RESULTS: High expression of CCAT2 induced CIN in CRC cell lines and increased resistance to 5-fluorouracil and oxaliplatin. Mice that expressed the CCAT2 transgene developed chromosome abnormalities, and colon organoids derived from crypt cells of these mice had a higher percentage of chromosome abnormalities compared with organoids from control mice. The transgenic mice given azoxymethane and dextran sulfate sodium developed more and larger colon polyps than control mice given these agents. Microarray analysis and mass spectrometry indicated that expression of CCAT2 increased expression of genes involved in ribosome biogenesis and protein synthesis. CCAT2 lncRNA interacted directly with and stabilized BOP1 ribosomal biogenesis factor (BOP1). CCAT2 also increased expression of MYC, which activated expression of BOP1. Overexpression of BOP1 in CRC cell lines resulted in chromosomal missegregation errors, and increased colony formation, and invasiveness, whereas BOP1 knockdown reduced viability. BOP1 promoted CIN by increasing the active form of aurora kinase B, which regulates chromosomal segregation. BOP1 was overexpressed in polyp tissues from CCAT2 transgenic mice compared with healthy tissue. CCAT2 lncRNA and BOP1 mRNA or protein were all increased in microsatellite stable tumors (characterized by CIN), but not in tumors with microsatellite instability compared with nontumor tissues. Increased levels of CCAT2 lncRNA and BOP1 mRNA correlated with each other and with shorter survival times of patients. CONCLUSIONS: We found that overexpression of CCAT2 in colon cells promotes CIN and carcinogenesis by stabilizing and inducing expression of BOP1 an activator of aurora kinase B. Strategies to target this pathway might be developed for treatment of patients with microsatellite stable colorectal tumors.

• MeSH
• aurora kinasa B metabolismus   MeSH
• azoxymethan toxicita   MeSH
• chemorezistence genetika   MeSH
• chromozomální nestabilita * MeSH
• cytogenetické vyšetření MeSH
• dextrany toxicita   MeSH
• experimentální nádory chemicky indukované   genetika   patologie   MeSH
• genový knockdown MeSH
• karcinogeneze genetika   MeSH
• kolon cytologie   patologie   MeSH
• kolorektální nádory chemicky indukované   genetika   patologie   MeSH
• lidé MeSH
• myši transgenní MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• organoidy MeSH
• primární buněčná kultura MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   terapeutické užití   MeSH
• protoonkogenní proteiny c-myc metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• RNA dlouhá nekódující genetika   metabolismus   MeSH
• signální transdukce genetika   MeSH
• střevní sliznice cytologie   patologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

BACKGROUND: Microbial sensing by Toll-like receptors (TLR) and its negative regulation have an important role in the pathogenesis of inflammation-related cancer. In this study, we investigated the role of negative regulation of Toll-like receptors signaling and gut microbiota in the development of colitis-associated cancer in mouse model. METHODS: Colitis-associated cancer was induced by azoxymethane and dextran sodium sulfate in wild-type and in interleukin-1 receptor-associated kinase M (IRAK-M)-deficient mice with or without antibiotic (ATB) treatment. Local cytokine production was analyzed by multiplex cytokine assay or enzyme-linked immunosorbent assay, and regulatory T cells were analyzed by flow cytometry. Changes in microbiota composition during tumorigenesis were analyzed by pyrosequencing, and β-glucuronidase activity was measured in intestinal content by fluorescence assay. RESULTS: ATB treatment of wild-type mice reduced the incidence and severity of tumors. Compared with nontreated mice, ATB-treated mice had significantly lower numbers of regulatory T cells in colon, altered gut microbiota composition, and decreased β-glucuronidase activity. However, the β-glucuronidase activity was not as low as in germ-free mice. IRAK-M-deficient mice not only developed invasive tumors, but ATB-induced decrease in β-glucuronidase activity did not rescue them from severe carcinogenesis phenotype. Furthermore, IRAK-M-deficient mice had significantly increased levels of proinflammatory cytokines in the tumor tissue. CONCLUSIONS: We conclude that gut microbiota promotes tumorigenesis by increasing the exposure of gut epithelium to carcinogens and that IRAK-M-negative regulation is essential for colon cancer resistance even in conditions of altered microbiota. Therefore, gut microbiota and its metabolic activity could be potential targets for colitis-associated cancer therapy.

• MeSH
• azoxymethan toxicita   MeSH
• cytokiny genetika   metabolismus   MeSH
• gastrointestinální trakt mikrobiologie   MeSH
• karcinogeny toxicita   MeSH
• kinázy asociované s receptory interleukinu-1 fyziologie   MeSH
• kolitida chemicky indukované   komplikace   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• messenger RNA genetika   MeSH
• metagenom * MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• nádory tračníku etiologie   metabolismus   patologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• průtoková cytometrie MeSH
• receptory interleukinu-1 metabolismus   MeSH
• regulační T-lymfocyty imunologie   metabolismus   patologie   MeSH
• signální transdukce MeSH
• síran dextranu toxicita   MeSH
• toll-like receptory genetika   metabolismus   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH