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Inactivation of mTORC2 in macrophages is a signature of colorectal cancer that promotes tumorigenesis.
Katholnig K, Schütz B, Fritsch SD, Schörghofer D, Linke M, Sukhbaatar N, Matschinger JM, Unterleuthner D, Hirtl M, Lang M, Herac M, Spittler A, Bergthaler A, Schabbauer G, Bergmann M, Dolznig H, Hengstschläger M, Magnuson MA, Mikula M, Weichhart T
(2019) JCI Insight 4:
MeSH Terms: Animals, Carcinogenesis, Cell Line, Tumor, Cell Proliferation, Cells, Cultured, Colitis, Ulcerative, Colon, Colorectal Neoplasms, Dextran Sulfate, Disease Models, Animal, Female, Humans, Intestinal Mucosa, Kaplan-Meier Estimate, Macrophages, Male, Mechanistic Target of Rapamycin Complex 2, Mice, Mice, Transgenic, Morpholines, Osteopontin, Primary Cell Culture, Prognosis, Survival Rate
Show Abstract · Added November 6, 2019
The mechanistic target of rapamycin complex 2 (mTORC2) is a potentially novel and promising anticancer target due to its critical roles in proliferation, apoptosis, and metabolic reprogramming of cancer cells. However, the activity and function of mTORC2 in distinct cells within malignant tissue in vivo is insufficiently explored. Surprisingly, in primary human and mouse colorectal cancer (CRC) samples, mTORC2 signaling could not be detected in tumor cells. In contrast, only macrophages in tumor-adjacent areas showed mTORC2 activity, which was downregulated in stromal macrophages residing within human and mouse tumor tissues. Functionally, inhibition of mTORC2 by specific deletion of Rictor in macrophages stimulated tumorigenesis in a colitis-associated CRC mouse model. This phenotype was driven by a proinflammatory reprogramming of mTORC2-deficient macrophages that promoted colitis via the cytokine SPP1/osteopontin to stimulate tumor growth. In human CRC patients, high SPP1 levels and low mTORC2 activity in tumor-associated macrophages correlated with a worsened clinical prognosis. Treatment of mice with a second-generation mTOR inhibitor that inhibits mTORC2 and mTORC1 exacerbated experimental colorectal tumorigenesis in vivo. In conclusion, mTORC2 activity is confined to macrophages in CRC and limits tumorigenesis. These results suggest activation but not inhibition of mTORC2 as a therapeutic strategy for colitis-associated CRC.
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24 MeSH Terms
Increased Epithelial Oxygenation Links Colitis to an Expansion of Tumorigenic Bacteria.
Cevallos SA, Lee JY, Tiffany CR, Byndloss AJ, Johnston L, Byndloss MX, Bäumler AJ
(2019) mBio 10:
MeSH Terms: Aerobiosis, Animals, Carcinogenesis, Colitis, Colorectal Neoplasms, Dextran Sulfate, Escherichia coli, Escherichia coli Infections, Female, Gastrointestinal Microbiome, Mice, Mice, Inbred C57BL, Oxygen, Peptides, Polyketides
Show Abstract · Added March 30, 2020
Intestinal inflammation is a risk factor for colorectal cancer formation, but the underlying mechanisms remain unknown. Here, we investigated whether colitis alters the colonic microbiota to enhance its cancer-inducing activity. Colitis increased epithelial oxygenation in the colon of mice and drove an expansion of within the gut-associated microbial community through aerobic respiration. An aerobic expansion of colibactin-producing was required for the cancer-inducing activity of this pathobiont in a mouse model of colitis-associated colorectal cancer formation. We conclude that increased epithelial oxygenation in the colon is associated with an expansion of a prooncogenic driver species, thereby increasing the cancer-inducing activity of the microbiota. One of the environmental factors important for colorectal cancer formation is the gut microbiota, but the habitat filters that control its cancer-inducing activity remain unknown. Here, we show that chemically induced colitis elevates epithelial oxygenation in the colon, thereby driving an expansion of colibactin-producing , a prooncogenic driver species. These data suggest that elevated epithelial oxygenation is a potential risk factor for colorectal cancer formation because the consequent changes in the gut habitat escalate the cancer-inducing activity of the microbiota.
Copyright © 2019 Cevallos et al.
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15 MeSH Terms
Editing of the gut microbiota reduces carcinogenesis in mouse models of colitis-associated colorectal cancer.
Zhu W, Miyata N, Winter MG, Arenales A, Hughes ER, Spiga L, Kim J, Sifuentes-Dominguez L, Starokadomskyy P, Gopal P, Byndloss MX, Santos RL, Burstein E, Winter SE
(2019) J Exp Med 216: 2378-2393
MeSH Terms: Animals, Colitis, Colorectal Neoplasms, Dextran Sulfate, Dysbiosis, Escherichia coli, Gastrointestinal Microbiome, Interleukin-10, Mice, Neoplasms, Experimental
Show Abstract · Added March 30, 2020
Chronic inflammation and gut microbiota dysbiosis, in particular the bloom of genotoxin-producing strains, are risk factors for the development of colorectal cancer. Here, we sought to determine whether precision editing of gut microbiota metabolism and composition could decrease the risk for tumor development in mouse models of colitis-associated colorectal cancer (CAC). Expansion of experimentally introduced strains in the azoxymethane/dextran sulfate sodium colitis model was driven by molybdoenzyme-dependent metabolic pathways. Oral administration of sodium tungstate inhibited molybdoenzymes and selectively decreased gut colonization with genotoxin-producing and other Enterobacteriaceae. Restricting the bloom of Enterobacteriaceae decreased intestinal inflammation and reduced the incidence of colonic tumors in two models of CAC, the azoxymethane/dextran sulfate sodium colitis model and azoxymethane-treated, -deficient mice. We conclude that metabolic targeting of protumoral Enterobacteriaceae during chronic inflammation is a suitable strategy to prevent the development of malignancies arising from gut microbiota dysbiosis.
© 2019 Zhu et al.
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10 MeSH Terms
Systematic review with meta-analysis: association between Helicobacter pylori CagA seropositivity and odds of inflammatory bowel disease.
Tepler A, Narula N, Peek RM, Patel A, Edelson C, Colombel JF, Shah SC
(2019) Aliment Pharmacol Ther 50: 121-131
MeSH Terms: Adolescent, Adult, Antibodies, Bacterial, Antigens, Bacterial, Bacterial Proteins, Colitis, Ulcerative, Comorbidity, Crohn Disease, Female, Helicobacter Infections, Helicobacter pylori, Humans, Inflammatory Bowel Diseases, Male, Middle Aged, Seroepidemiologic Studies, Young Adult
Show Abstract · Added March 3, 2020
BACKGROUND - Accumulating data support a protective role of Helicobacter pylori against inflammatory bowel diseases (IBD), which might be mediated by strain-specific constituents, specifically cagA expression.
AIM - To perform a systematic review and meta-analysis to more clearly define the association between CagA seropositivity and IBD.
METHODS - We identified comparative studies that included sufficient detail to determine the odds or risk of IBD, Crohn's disease (CD) or ulcerative colitis (UC) amongst individuals with vs without evidence of cagA expression (eg CagA seropositivity). Estimates were pooled using a random effects model.
RESULTS - Three clinical studies met inclusion criteria. cagA expression was represented by CagA seropositivity in all studies. Compared to CagA seronegativity overall, CagA seropositivity was associated with lower odds of IBD (OR 0.31, 95% CI 0.21-0.44) and CD (OR 0.25, 95% CI 0.17-0.38), and statistically nonsignificant lower odds for UC (OR 0.68, 95% CI 0.35-1.32). Similarly, compared to H pylori non-exposed individuals, H pylori exposed, CagA seropositive individuals had lower odds of IBD (OR 0.26, 95% CI 0.16-0.41) and CD (OR 0.23, 95% CI 0.15-0.35), but not UC (OR 0.66, 0.34-1.27). However, there was no significant difference in the odds of IBD, CD or UC between H pylori exposed, CagA seronegative and H pylori non-exposed individuals.
CONCLUSION - We found evidence for a significant association between CagA seropositive H pylori exposure and reduced odds of IBD, particularly CD, but not for CagA seronegative H pylori exposure. Additional studies are needed to confirm these findings and define underlying mechanisms.
© 2019 John Wiley & Sons Ltd.
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17 MeSH Terms
Dietary Arginine Regulates Severity of Experimental Colitis and Affects the Colonic Microbiome.
Singh K, Gobert AP, Coburn LA, Barry DP, Allaman M, Asim M, Luis PB, Schneider C, Milne GL, Boone HH, Shilts MH, Washington MK, Das SR, Piazuelo MB, Wilson KT
(2019) Front Cell Infect Microbiol 9: 66
MeSH Terms: Animals, Arginine, Citrobacter rodentium, Colitis, Colon, Dextran Sulfate, Diet, Disease Models, Animal, Enterobacteriaceae Infections, Gastrointestinal Microbiome, Histocytochemistry, Mice, Inbred C57BL, Treatment Outcome
Show Abstract · Added April 12, 2019
There is great interest in safe and effective alternative therapies that could benefit patients with inflammatory bowel diseases (IBD). L-arginine (Arg) is a semi-essential amino acid with a variety of physiological effects. In this context, our aim was to investigate the role of dietary Arg in experimental colitis. We used two models of colitis in C57BL/6 mice, the dextran sulfate sodium (DSS) model of injury and repair, and infection. Animals were given diets containing (1) no Arg (Arg), 6.4 g/kg (Arg), or 24.6 g/kg Arg (Arg); or (2) the amino acids downstream of Arg: 28 g/kg L-ornithine (Orn) or 72 g/kg L-proline (Pro). Mice with DSS colitis receiving the Arg diet had increased levels of Arg, Orn, and Pro in the colon and improved body weight loss, colon length shortening, and histological injury compared to Arg and Arg diets. Histology was improved in the Arg vs. Arg group. Orn or Pro diets did not provide protection. Reduction in colitis with Arg diet also occurred in -infected mice. Diversity of the intestinal microbiota was significantly enhanced in mice on the Arg diet compared to the Arg or Arg diets, with increased abundance of Bacteroidetes and decreased Verrucomicrobia. In conclusion, dietary supplementation of Arg is protective in colitis models. This may occur by restoring overall microbial diversity and Bacteroidetes prevalence. Our data provide a rationale for Arg as an adjunctive therapy in IBD.
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13 MeSH Terms
Upregulated claudin-1 expression promotes colitis-associated cancer by promoting β-catenin phosphorylation and activation in Notch/p-AKT-dependent manner.
Gowrikumar S, Ahmad R, Uppada SB, Washington MK, Shi C, Singh AB, Dhawan P
(2019) Oncogene 38: 5321-5337
MeSH Terms: Animals, Biomarkers, Tumor, Cells, Cultured, Claudin-1, Colitis, Colonic Neoplasms, Gene Expression Regulation, Neoplastic, HT29 Cells, Humans, Inflammatory Bowel Diseases, Intestinal Mucosa, Mice, Mice, Inbred C57BL, Mice, Transgenic, Phosphorylation, Prognosis, Protein Processing, Post-Translational, Proto-Oncogene Proteins c-akt, Receptors, Notch, Signal Transduction, Up-Regulation, beta Catenin
Show Abstract · Added April 24, 2019
In IBD patients, integration between a hyper-activated immune system and epithelial cell plasticity underlies colon cancer development. However, molecular regulation of such a circuity remains undefined. Claudin-1 (Cld-1), a tight-junction integral protein deregulation alters colonic epithelial cell (CEC) differentiation, and promotes colitis severity while impairing colitis-associated injury/repair. Tumorigenesis is a product of an unregulated wound-healing process and therefore we postulated that upregulated Cld-1 levels render IBD patients susceptible to the colitis-associated cancer (CAC). Villin Cld-1 mice are used to carryout overexpressed studies in mice. The role of deregulated Cld-1 expression in CAC and the underlying mechanism was determined using a well-constructed study scheme and mouse models of DSS colitis/recovery and CAC. Using an inclusive investigative scheme, we here report that upregulated Cld-1 expression promotes susceptibility to the CAC and its malignancy. Increased mucosal inflammation and defective epithelial homeostasis accompanied the increased CAC in Villin-Cld-1-Tg mice. We further found significantly increased levels of protumorigenic M2 macrophages and β-cateninSer552 (β-CatSer552) expression in the CAC in Cld-1Tg vs. WT mice. Mechanistic studies identified the role of PI3K/Akt signaling in Cld-1-dependent activation of the β-CatSer552, which, in turn, was dependent on proinflammatory signals. Our studies identify a critical role of Cld-1 in promoting susceptibility to CAC. Importantly, these effects of deregulated Cld-1 were not associated with altered tight junction integrity, but on its noncanonical role in regulating Notch/PI3K/Wnt/ β-CatSer552 signaling. Overall, outcome from our current studies identifies Cld-1 as potential prognostic biomarker for IBD severity and CAC, and a novel therapeutic target.
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22 MeSH Terms
Kaiso is required for MTG16-dependent effects on colitis-associated carcinoma.
Short SP, Barrett CW, Stengel KR, Revetta FL, Choksi YA, Coburn LA, Lintel MK, McDonough EM, Washington MK, Wilson KT, Prokhortchouk E, Chen X, Hiebert SW, Reynolds AB, Williams CS
(2019) Oncogene 38: 5091-5106
MeSH Terms: Adenocarcinoma, Animals, Carcinogenesis, Colitis, Colonic Neoplasms, Female, HCT116 Cells, HEK293 Cells, Humans, Inflammation, Intestinal Mucosa, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Repressor Proteins, Transcription Factors
Show Abstract · Added March 16, 2019
The myeloid translocation gene family member MTG16 is a transcriptional corepressor that relies on the DNA-binding ability of other proteins to determine specificity. One such protein is the ZBTB family member Kaiso, and the MTG16:Kaiso interaction is necessary for repression of Kaiso target genes, such as matrix metalloproteinase-7. Using the azoxymethane and dextran sodium sulfate (AOM/DSS) murine model of colitis-associated carcinoma, we previously determined that MTG16 loss accelerates tumorigenesis and inflammation. However, it was unknown whether this effect was modified by Kaiso-dependent transcriptional repression. To test for a genetic interaction between MTG16 and Kaiso in inflammatory carcinogenesis, we subjected single and double knockout (DKO) mice to the AOM/DSS protocol. Mtg16 mice demonstrated increased colitis and tumor burden; in contrast, disease severity in Kaiso mice was equivalent to wild-type controls. Surprisingly, Kaiso deficiency in the context of MTG16 loss reversed injury and pro-tumorigenic responses in the intestinal epithelium following AOM/DSS treatment, and tumor numbers were returned to near to wild-type levels. Transcriptomic analysis of non-tumor colon tissue demonstrated that changes induced by MTG16 loss were widely mitigated by concurrent Kaiso loss, and DKO mice demonstrated downregulation of metabolism and cytokine-associated gene sets with concurrent activation of DNA damage checkpoint pathways as compared with Mtg16. Further, Kaiso knockdown in intestinal enteroids reduced stem- and WNT-associated phenotypes, thus abrogating the induction of these pathways observed in Mtg16 samples. Together, these data suggest that Kaiso modifies MTG16-driven inflammation and tumorigenesis and suggests that Kaiso deregulation contributes to MTG16-dependent colitis and CAC phenotypes.
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17 MeSH Terms
Microbiota-nourishing Immunity and Its Relevance for Ulcerative Colitis.
Byndloss MX, Litvak Y, Bäumler AJ
(2019) Inflamm Bowel Dis 25: 811-815
MeSH Terms: Colitis, Ulcerative, Dysbiosis, Humans, Microbiota, Probiotics
Added March 30, 2020
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MeSH Terms
mPGES-1-Mediated Production of PGE and EP4 Receptor Sensing Regulate T Cell Colonic Inflammation.
Maseda D, Banerjee A, Johnson EM, Washington MK, Kim H, Lau KS, Crofford LJ
(2018) Front Immunol 9: 2954
MeSH Terms: Animals, CD4-Positive T-Lymphocytes, Colitis, Dinoprostone, Intestinal Mucosa, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Nuclear Receptor Subfamily 1, Group F, Member 3, Prostaglandin-E Synthases, Receptors, Prostaglandin E, EP2 Subtype, Receptors, Prostaglandin E, EP4 Subtype, T-Lymphocytes, T-Lymphocytes, Regulatory
Show Abstract · Added March 25, 2020
PGE is a lipid mediator of the initiation and resolution phases of inflammation, as well as a regulator of immune system responses to inflammatory events. PGE is produced and sensed by T cells, and autocrine or paracrine PGE can affect T cell phenotype and function. In this study, we use a T cell-dependent model of colitis to evaluate the role of PGE on pathological outcome and T-cell phenotypes. CD4 T effector cells either deficient in mPGES-1 or the PGE receptor EP4 are less colitogenic. Absence of T cell autocrine mPGES1-dependent PGE reduces colitogenicity in association with an increase in CD4RORγt cells in the lamina propria. In contrast, recipient mice deficient in mPGES-1 exhibit more severe colitis that corresponds with a reduced capacity to generate FoxP3 T cells, especially in mesenteric lymph nodes. Thus, our research defines how mPGES-1-driven production of PGE by different cell types in distinct intestinal locations impacts T cell function during colitis. We conclude that PGE has profound effects on T cell phenotype that are dependent on the microenvironment.
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Systematic Review and Meta-analysis: Optimal Salvage Therapy in Acute Severe Ulcerative Colitis.
Choy MC, Seah D, Faleck DM, Shah SC, Chao CY, An YK, Radford-Smith G, Bessissow T, Dubinsky MC, Ford AC, Churilov L, Yeomans ND, De Cruz PP
(2019) Inflamm Bowel Dis 25: 1169-1186
MeSH Terms: Acute Disease, Colitis, Ulcerative, Gastrointestinal Agents, Humans, Infliximab, Salvage Therapy, Severity of Illness Index, Treatment Outcome
Show Abstract · Added March 3, 2020
BACKGROUND - Infliximab is an effective salvage therapy in acute severe ulcerative colitis; however, the optimal dosing strategy is unknown. We performed a systematic review and meta-analysis to examine the impact of infliximab dosage and intensification on colectomy-free survival in acute severe ulcerative colitis.
METHODS - Studies reporting outcomes of hospitalized steroid-refractory acute severe ulcerative colitis treated with infliximab salvage were identified. Infliximab use was categorized by dose, dose number, and schedule. The primary outcome was colectomy-free survival at 3 months. Pooled proportions and odds ratios with 95% confidence intervals were reported.
RESULTS - Forty-one cohorts (n = 2158 cases) were included. Overall colectomy-free survival with infliximab salvage was 79.7% (95% confidence interval [CI], 75.48% to 83.6%) at 3 months and 69.8% (95% CI, 65.7% to 73.7%) at 12 months. Colectomy-free survival at 3 months was superior with 5-mg/kg multiple (≥2) doses compared with single-dose induction (odds ratio [OR], 4.24; 95% CI, 2.44 to 7.36; P < 0.001). However, dose intensification with either high-dose or accelerated strategies was not significantly different to 5-mg/kg standard induction at 3 months (OR, 0.70; 95% CI, 0.39 to 1.27; P = 0.24) despite being utilized in patients with a significantly higher mean C-reactive protein and lower albumin levels.
CONCLUSIONS - In acute severe ulcerative colitis, multiple 5-mg/kg infliximab doses are superior to single-dose salvage. Dose-intensified induction outcomes were not significantly different compared to standard induction and were more often used in patients with increased disease severity, which may have confounded the results. This meta-analysis highlights the marked variability in the management of infliximab salvage therapy and the need for further studies to determine the optimal dose strategy.
© 2019 Crohn’s & Colitis Foundation. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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8 MeSH Terms