DNA modifications such as 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are epigenetic marks known to affect global gene expression in mammals. Given their prevalence in the human genome, close correlation with gene expression and high chemical stability, these DNA epigenetic marks could serve as ideal biomarkers for cancer diagnosis. Taking advantage of a highly sensitive and selective chemical labeling technology, we report here the genome-wide profiling of 5hmC in circulating cell-free DNA (cfDNA) and in genomic DNA (gDNA) of paired tumor and adjacent tissues collected from a cohort of 260 patients recently diagnosed with colorectal, gastric, pancreatic, liver or thyroid cancer and normal tissues from 90 healthy individuals. 5hmC was mainly distributed in transcriptionally active regions coincident with open chromatin and permissive histone modifications. Robust cancer-associated 5hmC signatures were identified in cfDNA that were characteristic for specific cancer types. 5hmC-based biomarkers of circulating cfDNA were highly predictive of colorectal and gastric cancers and were superior to conventional biomarkers and comparable to 5hmC biomarkers from tissue biopsies. Thus, this new strategy could lead to the development of effective, minimally invasive methods for diagnosis and prognosis of cancer from the analyses of blood samples.

Background Little is known about the role of the microbiome in primary sclerosing cholangitis. Aim Our goal was to explore the mucosa-associated microbiota in PSC patients across different locations in the gut, and to compare it with IBD-only patients and healthy controls. Methods Biopsies from the terminal ileum, right colon, and left colon were collected from patients and healthy controls undergoing colonoscopy. Microbiota profiling using bacterial 16S rRNA sequencing was performed on all biopsies. Results Forty-four patients were recruited: 20 with PSC (19 with PSC-IBD and one with PSC-only), 15 with IBD-only, and 9 healthy controls. The overall microbiome profile was similar throughout different locations in the gut. No differences in the global microbiome profile were found. However, we observed significant PSC-associated enrichment in Barnesiellaceae at the family level, and in Blautia and an unidentified Barnesiellaceae at the genus level. At the operational taxa unit (OTU) level, most shifts in PSC were observed in Clostridiales and Bacteroidales orders, with approximately 86% of shifts occurring within the former order. Conclusion The overall microbiota profile was similar across multiple locations in the gut from the same individual regardless of disease status. In this study, the mucosa associated-microbiota of PSC patients was characterized by enrichment of Blautia and Barnesiellaceae and by major shifts in OTUs within Clostridiales order.

Pathological substance use disorders represent a major public health crisis with limited effective treatment options. While much work has been done to understand the neuronal signaling networks and intracellular signaling cascades associated with prolonged drug use, these studies have yielded few successful treatment options for substance use disorders. In recent years, there has been a growing interest to explore interactions between the peripheral immune system, the gut microbiome and the CNS. In this review we will present a summary of existing evidence, suggesting a potential role for gut dysbiosis in the pathogenesis of substance use disorders. Clinical evidence of gut dysbiosis in human subjects with substance use disorder as well as preclinical evidence of gut dysbiosis in animal models of drug addiction are discussed in detail. Additionally, we examine how changes in the gut microbiome and its metabolites may not only be a consequence of substance use disorders but may in fact play a role in mediating behavioral response to drugs of abuse. While much work still needs to be done, understanding the interplay of gut microbiome in substance use disorders may offers a promising avenue for future therapeutic development.

Increasing KYNA/T is closely associated with endoscopic inflammation and predictive of disease outcomes in patients with UC. These findings identify this novel metabolic association and further support the role of the KP in regulating mucosal inflammation in UC. 10.1093/ibd/izy103_video1izy103.video15788135676001.

Purpose Patients with ulcerative colitis (UC) are at increased risk for colorectal cancer, although mechanisms underlying neoplastic transformation are poorly understood. We sought to evaluate the role of microRNAs in neoplasia development in this high-risk population. Experimental Design Tissue from 12 controls, 9 UC patients without neoplasia, and 11 UC patients with neoplasia was analyzed. miRNA array analysis was performed and select miRNAs assayed by real-time PCR on the discovery cohort and a validation cohort. DNA methylation of miR-193a was assessed. Following transfection of miR-193a-3p, proliferation, IL17RD expression, and luciferase activity of the 3’UTR of IL17RD were measured. Tumor growth in xenografts as well as EGFR signaling were assessed in HCT116 cells expressing IL17RD with either a mutant 3’ untranslated region (UTR) or wild-type (WT) 3’UTR. Results miR-31, miR-34a, miR-106b, and miR-193a-3p were significantly dysregulated in UC-neoplasia and adjacent tissue. Significant down-regulation of miR-193a-3p was also seen in an independent cohort of UC-cancers. Changes in methylation of miR-193a or expression of pri-miR-193a were not observed in UC-cancer. Transfection of miR-193a-3p resulted in decreased proliferation, and identified IL17RD as a direct target of miR-193a-3p. IL17RD expression was increased in UC-cancers, and miR-193a-3p treatment decreased growth and EGFR signaling of HCT116 cells in xenografts expressing both IL17RD with WT 3’UTR compared to cells expressing IL17RD with mutant 3’UTR. Conclusions miR-193a-3p is down-regulated in UC-neoplasia, and its loss promotes carcinogenesis through up-regulation of IL17RD. These findings provide novel insight into inflammation-driven CRC and could suggest new therapeutic targets in this high-risk population.