Methylenetetrahydrofolate reductase polymorphisms and colorectal cancer prognosis: A meta-analysis.

BACKGROUND: The present study focused on understanding the prognostic value of the methylenetetrahydrofolate reductase (MTHFR) single nucleotide polymorphisms rs1801133 (C667T) and rs1801131 (A1298C) in patients with colorectal cancer (CRC). METHODS: A systematic literature search was conducted in March 2016. Databases, including Medline, EMBASE, Cochrane and Chinese databases (including CNKI, Wanfang and VIP), were searched to identify the relevant articles describing MTHFR polymorphisms in patients with CRC. Data regarding overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS) were collected and analysed. RESULTS: Twenty-four studies with 5423 patients with CRC were included. Significant differences in OS, PFS and DFS were not observed among the different comparisons of patients carrying different alleles of the MTHFR rs1801133 polymorphism (including TT versus CC, TT versus CT + CC, CT + TT versus CC and CT versus CC). Compared with patients with the rs1801131 CA + AA genotypes, patients with the CC genotype had a shorter OS (hazard ratio = 1.85; 95% confidence interval = 1.30-2.65) and DFS (hazard ratio = 2.16; 95% confidence interval= 1.19-3.93). Significant differences in OS, PFS and DFS were not observed among the other patient groups (including CC versus AA, CC + CA versus AA and CA versus AA). Subgroup analysis of rs1801133 and rs1801131 showed that patients with CRC from Asian regions and Western regions demonstrated similar results. CONCLUSIONS: The MTHFR rs1801133 polymorphism was not associated with the prognosis of patients with CRC; however, rs1801131 may be associated with the prognosis of patients with CRC. Well-designed prospective studies are necessary to obtain a better understanding of the prognostic value of rs1801133 and rs1801131.

MiR-144 Increases Intestinal Permeability in IBS-D Rats by Targeting OCLN and ZO1.

BACKGROUND/AIMS: Irritable bowel syndrome with diarrhoea (IBS-D) is a chronic, functional bowel disorder characterized by abdominal pain or diarrhoea and altered bowel habits, which correlate with intestinal hyperpermeability. MicroRNAs (miRNAs) are involved in regulating intestinal permeability in IBS-D. However, the role of miRNAs in regulating intestinal permeability and protecting the epithelial barrier remains unclear. Our goals were to (i) identify differential expression of miRNAs and their targets in the distal colon of IBS-D rats; (ii) verify in vitro whether occludin (OCLN) and zonula occludens 1 (ZO1/TJP1) were direct targets of miR-144 and were down-regulated in IBS-D rats; and (iii) determine whether down-regulation of miR-144 in vitro could reverse the pathological hallmarks of intestinal hyperpermeability via targeting OCLN and ZO1. METHODS: The IBS-D rat model was established using 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. The distal colon was obtained in order to perform miRNA microarray analysis and to isolate and culture colonic epithelial cells. When differential expression of miRNA was found, the results were verified by qRT-PCR, and the target genes were further explored by bioinformatics analysis. Correlation analyses were carried out to compare the expression of miRNA and target genes. Then, mutants, miRNA mimics and inhibitors of the target genes were constructed and transfected to colonic epithelial cells. qRT-PCR, western blotting, enzyme-linked immunosorbent assays (ELISAs) and dual-luciferase assays were used to investigate the expression of miR-144 and OCLN, ZO1 in IBS-D rats. RESULTS: There were 8 up-regulated and 18 down-regulated miRNAs identified in the IBS-D rat model. Of these, miR-144 was markedly up-regulated and resulted in the down-regulation of OCLN and ZO1 expression. Overexpression of miR-144 by transfection of miR-144 precursor markedly inhibited the expression of OCLN and ZO1. Further studies confirmed that OCLN and ZO1 were direct targets of miR-144. Additionally, intestinal hyperpermeability was enhanced by miR-144 up-regulation and attenuated by miR-144 down-regulation in IBS-D rat colonic epithelial cells. Moreover, rescue experiments showed that overexpression of OCLN and ZO1 significantly eliminated the inhibitory effect of miR-144, which showed a stronger effect on the attenuation of intestinal hyperpermeability. CONCLUSION: Up-regulation of miR-144 could promote intestinal hyperpermeability and impair the protective effect of the epithelial barrier by directly targeting OCLN and ZO1. miR-144 is likely a key regulator of intestinal hyperpermeability and could be a potential therapeutic target for IBS-D.

Prognostic value of transforming growth factor-beta in patients with colorectal cancer who undergo surgery: a meta-analysis.

BACKGROUND: Transforming growth factor-beta (TGF-ß) is associated with a higher incidence of distant metastasis and decreased survival. Whether TGF-ß can be used as a prognostic indicator of colorectal cancer (CRC) remains controversial. METHODS: The Medline, EMBASE and Cochrane databases were searched from their inception to March 2016. The studies that focused on TGF-ß as a prognostic factor in patients with CRC were included in this analysis. Overall survival (OS) and disease-free survival (DFS) were analysed separately. A meta-analysis was performed, and hazard ratios (HR) with 95% confidence intervals (CI) were calculated. RESULTS: Twelve studies were included in the analysis, of which 8 were used for OS and 7 for DFS. In all, 1622 patients with CRC undergoing surgery were included. Combined HRs suggested that high expression of TGF-ß had a favourable impact on OS (HR = 1.68, 95% CI: 1.10-2.59) and DFS (HR = 1.11, 95% CI: 1.03-1.19) in CRC patients. For OS, the combined HRs of Asian studies and Western studies were 1.50 (95% CI: 0.61-3.68) and 1.80 (95% CI: 1.33-2.45), respectively. For DFS, the combined HRs of Asian studies and Western studies were 1.42 (95% CI: 0.61-3.31) and 1.11 (95% CI: 1.03-1.20), respectively. CONCLUSIONS: This meta-analysis demonstrates that TGF-ß can be used as a prognostic biomarker for CRC patients undergoing surgery, especially for CRC patients from Western countries.

Efficacy of Tong-Xie-Yao-Fang granule and its impact on whole transcriptome profiling in diarrhea-predominant irritable bowel syndrome patients: study protocol for a randomized controlled trial.

BACKGROUND: Irritable bowel syndrome (IBS) is one kind of common functional bowel disease with obscure pathogenesis, and exploration about whole transcriptome profiling in IBS-D is still negligible. Conventional medications have limited effects, which makes focus shifted to traditional Chinese medicine (TCM). Tong-Xie-Yao-Fang, as a classic herbal formula in TCM, is pretty effective and safe for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D), but the underlying therapeutic mechanism remains unknown. We aim to verify the efficacy and safety of TXYF granule (the formula particles mixed together) in IBS-D and elucidate the gene-level mechanism of IBS-D and therapeutic targets of TXYF granule based on whole transcriptome analysis. METHODS/DESIGN: This is a randomized, double-blind, and placebo-controlled clinical trial consisting of 2 weeks of run-in period, 12 weeks of treatment period, and 8 weeks of follow-up period. We will enroll 120 participants with IBS-D, who will be randomly assigned to the TXYF granule group and the placebo group, and recruit additional 10 healthy individuals as controls for mechanistic outcome. The two groups respectively take TXYF granule or placebo orally for treatment. The primary outcome is the response rate of IBS-Symptom Severity Score (IBS-SSS). The secondary outcomes include adequate relief (AR), IBS-Quality of Life Questionnaire (IBS-QOL), and long-term efficacy. Mechanistic outcome is the whole transcriptome profiling of the intestinal mucosae from IBS participants before and after the treatment and healthy individuals. DISCUSSION: This trial will prove the effectiveness and safety of TXYF granule with high-quality evidence and provide a penetrating and comprehensive perspective on the molecular mechanism of IBS-D by whole transcriptome analysis, which makes us pinpoint specific biomarkers of IBS-D and therapeutic targets of TXYF. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-IOR-1900021785 . Registered on 9 March 2019.

Berberine improves intestinal epithelial tight junctions by upregulating A20 expression in IBS-D mice.

To investigate effects of berberine exerts on A20 expression and regulation of intestinal epithelial tight junctions via the TNF-α-NF-κB-MLCK pathway in Diarrhea-Predominant Irritable Bowel Syndrome (IBS-D). C57BL/6 wild type (WT) and A20 IEC-KO mice (48 each) were randomly divided into normal control (NC), model control (MC), rifaximin and berberine groups (12 mice per group). An experimental model of IBS-D was established using 4% acetic acid and evaluated by haematoxylin-eosin (HE) staining. rifaximin and berberine mice were treated with rifaximin and berberine, respectively. Intestinal epithelial space of WT berberine mice improved more than A20 IEC-KO berberine mice compared to MC mice. WT berberine mice exhibited greater expression of A20 compared with MC mice(P < 0.01). TNF-α, NF-kB p65, MLCK, MLC, TRAF6 and RIP1 levels in A20 IEC-KO and WT berberine mice were all decreased compared to MC mice(P all<0.05). NF-κB p65, MLCK and TRAF6 levels were increased in A20 IEC-KO berberine mice as compared to WT berberine mice (P all<0.05). Intestinal epithelial levels of occludin, claudin-1, ZO-1 and F-actin increased in all berberine mice (P all<0.01-0.05), while occludin, claudin-1, and ZO-1 levels were lower in A20 IEC-KO berberine mice(P < 0.05). Berberine downregulates abnormal activation of the TNF-α-NF-κB-MLCK pathway by upregulating expression of A20 in a mouse model of IBS-D, thereby protecting intestinal epithelial tight junctions and repairing the damage IBS-D causes to the intestinal epithelial barrier.

MicroRNA-200a Targets Cannabinoid Receptor 1 and Serotonin Transporter to Increase Visceral Hyperalgesia in Diarrhea-predominant Irritable Bowel Syndrome Rats.

BACKGROUND/AIMS: MicroRNAs (miRNAs) were reported to be responsible for intestinal permeability in diarrhea-predominant irritable bowel syndrome (IBS-D) rats in our previous study. However, whether and how miRNAs regulate visceral hypersensitivity in IBS-D remains largely unknown. METHODS: We established the IBS-D rat model and evaluated it using the nociceptive visceral hypersensitivity test, myeloperoxidase activity assay, restraint stress-induced defecation, and electromyographic (EMG) activity. The distal colon was subjected to miRNA microarray analysis followed by isolation and culture of colonic epithelial cells (CECs). Bioinformatic analysis and further experiments, including dual luciferase assays, quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay, were used to detect the expression of miRNAs and how it regulates visceral hypersensitivity in IBS-D rats. RESULTS: The IBS-D rat model was successfully established. A total of 24 miRNAs were differentially expressed in the distal colon of IBS-D rats; 9 were upregulated and 15 were downregulated. Among them, the most significant upregulation was miR-200a, accompanied by downregulation of cannabinoid receptor 1 (CNR1) and serotonin transporter (SERT). MiR-200a mimic markedly inhibited the expression of CNR1/SERT. Bioinformatic analysis and luciferase assay confirmed that CNR1/SERT are direct targets of miR-200a. Rescue experiments that overexpressed CNR1/SERT significantly abolished the inhibitory effect of miR-200a on the IBS-D rats CECs. CONCLUSIONS: This study suggests that miR-200a could induce visceral hyperalgesia by targeting the downregulation of CNR1 and SERT, aggravating or leading to the development and progression of IBS-D. MiR-200a may be a regulator of visceral hypersensitivity, which provides potential targets for the treatment of IBS-D.