McKinzie, Sanna

This study compares gene expression in mucosa of the terminal ileum, right colon, and left colon in patients with diarrhea- or constipation-predominant irritable bowel syndrome (IBS) and contrasts expression between these two disease entities and also between each entity and mucosa from healthy controls. The study shows there is differential expression of genes related to immune, transmitter, nociceptive, ion channel, and transporter functions, as well as reduced serine protease inhibition, in patients with IBS.

INTRODUCTION: Previous studies in patients with irritable bowel syndrome (IBS) showed immune activation, secretion, and barrier dysfunction in duodenal, jejunal, or colorectal mucosa. This study aimed to measure ileal mucosal expression of genes and proteins associated with mucosal functions. METHODS: We measured by reverse transcription polymerase chain reaction messenger RNA (mRNA) expression of 78 genes (reflecting tight junction proteins, chemokines, innate immunity, ion channels, and transmitters) and 5 proteins (barrier, bile acid receptor, and ion exchanger) in terminal ileal mucosa from 11 patients with IBS-diarrhea (IBS-D), 17 patients with IBS-constipation (IBS-C), and 14 healthy controls. Fold changes in mRNA were calculated using 2 (−Δ, ΔCT) formula. Group differences were measured using analysis of variance. Protein ratios relative to healthy controls were based on Western blot analysis. Nominal P values ( P < 0.05) are reported. RESULTS: In ileal mucosal biopsies, significant differences of mRNA expression in IBS-D relative to IBS-C were upregulation of barrier proteins (TJP1, FN1, CLDN1, and CLDN12), repair function (TFF1), and cellular functions. In ileal mucosal biopsies, mRNA expression in IBS-C relative to healthy controls was reduced GPBAR1 receptor, myosin light chain kinase (MYLK in barrier function), and innate immunity (TLR3), but increased mRNA expression of cadherin cell adhesion mechanisms (CTNNB1) and transport genes SLC9A1 (Na-H exchanger [NHE1]) and INADL (indirect effect on ion transport). DISCUSSION: These data support a role of ileal mucosal dysfunction in IBS, including barrier dysfunction in IBS-D and alterations in absorption/secretion mechanisms in IBS-C.

To characterize α2-adrenergic control of motor and sensory functions of gastrointestinal tract and colon, we studied dose-related effects of clonidine (placebo or up to 0.3 mg po) by random assignment in 55 healthy humans. Gastrointestinal transit was measured in all subjects; in 35, we assessed colonic compliance, tone, and sensations of gas and pain during phasic distensions. Clonidine did not significantly alter gastrointestinal or colonic transit, but it increased colonic compliance and reduced fasting tone without altering colonic response to a meal. Clonidine significantly reduced aggregate sensation to distensions overall and had significant linear dose-related sensory effects at 8- and 24-mmHg distensions. Effect on pain (including dose-response relationship) was due to 0.3-mg dose for distensions at 24 mmHg. We confirmed that clonidine relaxes fasting colonic tone and reduces sensation of pain. In this study, gut transit was not altered by clonidine, and novel dose-response characteristics and clonidine's effect on gas sensation are provided. Doses as low as 0.05 mg may be effective and potentially useful in reducing colonic tone and gas sensation.

Abstract Background: Endemic nasopharyngeal carcinoma (NPC) refers to non-keratinizing (NK) subtypes harboring Epstein Barr virus (EBV) that frequently express programmed death-ligand 1 (PD-L1). We recently reported ≥30% of NPC harbor MHC class 1 gene alterations in a whole genome study. Method: We investigated the activity of nivolumab (NIVO) & relationship with PD-L1 & HLA expression (exp) in tumor cells (TC) & tumor infiltrating cells (TIL). Eligible patient (pt)s had to fail ≥ 1 prior line of platinum-based chemo. NIVO (3mg/kg IV, q2 weeks) was given until disease progression (PD). Archived tumors were analyzed for PD-L1 (DAKO) & HLA mutations (indicated by loss of HLA-A &/or B exp). Result: A total of 45 pts were enrolled across 11 sites from Oct 2015 to June 2016. Overall, 43 and 44 pts were evaluable respectively for response rate (RR, RECIST) & adverse events (AE). The median age was 57 years, 77% pts were males & 84% were Asians. The median number of prior chemo was 3 (range 1-9 lines). Of the 43 evaluable pts, there were 8 confirmed (19%, 95% CI: 8-33%) & 1 unconfirmed partial response (PR), 17 PD (40%), 14 stable disease (SD, 33%) & 3 pts were not assessed. One pt (MD015-027) had an unconfirmed clinical CR in an occipital metastasis (met). Pts received a median of 3 cycles of NIVO (range 1 - 14). Median overall survival has not been reached yet. Of the 44 pts evaluable for AE, 8 (18.2%) had grade 3 or higher treatment-related AEs & 1 pt died of sepsis. The most common grade 3 or higher AEs were increase in alanine/aspartate aminotransferase (n=3), & 1 pt respectively for hyponatremia, neutropenia, fatigue & diarrhea. Of the 21 tumor samples analyzed, 11/21 (52%) had &gt;1% PD-L1 expressed mainly in TC. Table 1 outlines relationship between RR & PD-L1 exp. All pts with PR had &gt;5% PD-L1 exp & one pt (34003-022) with CR (nasopharynx) & PR (lung mets) had the highest exp (80%). Majority of pts with PD had &lt;1% PD-L1 exp tumors. One primary progressor (34003-032) had a PD-L1 +ve tumor harboring a complete loss of HLA-B signal (TC), but intact signal in TILs & stromal cells. Conclusion: NIVO is active in this heavily pre-treated group of pts with NK-NPC and longer follow-up is needed for survival endpoints. Preliminary result suggests PD-L1 exp may predict benefit from NIVO. The analytical result of all 45 tumors will be presented. Table 1.PD-L1 exp and RECIST response in 21 ptsPD-L1%espRR%PRSDPD0-11&lt;1%-265%24-10%--120%-1-30%11-80%1--Total498 Citation Format: Brigette B. Ma, Boon Cher Goh, Wan T. Lim, Kwok W. Lo, Edwin P. Hui, Jonathan W. Riess, Mark Agulnik, Alex Y. Chang, Julie A. Kish, Dean W. Lim, Douglas R. Adkins, Kevin J. Cullen, Barbara J. Gitlitz, Nathan R. Foster, Adam M. Pettinger, Sanna Mckinzie, Ka F. To, Brian Costello, Howard Streicher, Anthony T. Chan. Multicenter phase II study of nivolumab in previously treated patients with recurrent and metastatic non-keratinizing nasopharyngeal carcinoma - Mayo clinic Phase 2 Consortium P2C-MN026, NCI9742, NCT02339558 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT076. doi:10.1158/1538-7445.AM2017-CT076

To compare the effects of the κ-opioid agonist asimadoline and placebo on visceral sensation and gastrointestinal (GI) motor functions in humans, 91 healthy participants were randomized in a double-blind fashion to 0.15, 0.5, or 1.5 mg of asimadoline or placebo orally twice a day for 9 days. We assessed satiation (nutrient drink test), colonic compliance, tone, perception of colonic distension (barostat), and whole gut transit (scintigraphy). Treatment effect was assessed by analysis of covariance. Asimadoline increased nutrient drink intake ( P = 0.03). Asimadoline decreased colonic tone during fasting ( P = 0.03) without affecting postprandial colonic contraction, compliance, or transit. Gas scores in response to colonic distension were decreased with 0.5 mg of asimadoline at low levels (8 mmHg above operating pressure) of distension ( P = 0.04) but not at higher levels of distension. Asimadoline at 1.5 mg increased gas scores at 16 mmHg of distension ( P = 0.03) and pain scores at distensions of 8 and 16 mmHg ( P = 0.003 and 0.03, respectively) but not at higher levels of distension. Further studies of this compound in diseases with altered satiation or visceral sensation are warranted.

The glucagon-like peptide 1 (GLP-1) analog ROSE-010 reduced pain during acute exacerbations of irritable bowel syndrome (IBS). Our objective was to assess effects of ROSE-010 on several gastrointestinal (GI) motor and bowel functions in constipation-predominant IBS (IBS-C). In a single-center, randomized, parallel-group, double-blind, placebo-controlled, dose-response study, we evaluated safety, pharmacodynamics, and pharmacokinetics in female patients with IBS-C. ROSE-010 (30, 100, or 300 μg sc) or matching placebo was administered once daily for 3 consecutive days and on 1 day 2–10 days later. We measured GI and colonic transit by validated scintigraphy and gastric volumes by single-photon emission computed tomography. The primary end points were half time of gastric emptying of solids, colonic transit geometric center at 24 h, and gastric accommodation volume. Analysis included intent-to-treat principle, analysis of covariance (with body mass index as covariate), and Dunnett-Hsu test for multiple comparisons. Exposure to ROSE-010 was approximately dose-proportional across the dose range tested. Demographic data in four treatment groups of female IBS-C patients (total 46) were not different. Gastric emptying was significantly retarded by 100 and 300 μg of ROSE-010. There were no significant effects of ROSE-010 on gastric volumes, small bowel or colonic transit at 24 h, or bowel functions. The 30- and 100-μg doses accelerated colonic transit at 48 h. Adverse effects were nausea ( P < 0.001 vs. placebo) and vomiting ( P = 0.008 vs. placebo). Laboratory safety results were not clinically significant. In IBS-C, ROSE-010 delayed gastric emptying of solids but did not retard colonic transit or alter gastric accommodation; the accelerated colonic transit at 48 h with 30 and 100 μg of ROSE-010 suggests potential for relief of constipation in IBS-C.

BACKGROUND Prucalopride (R093877) is a selective and specific 5HT 4 agonist, the first of a new chemical class of benzofurans, with gastrointestinal prokinetic activities in vitro. AIMS To evaluate the effects of prucalopride on gastrointestinal and colonic transit. METHODS A validated scintigraphic technique was used to measure gastrointestinal and colonic transit over 48 hours in 50 healthy volunteers. For seven days, each subject received a daily dose of 0.5, 1, 2, or 4 mg prucalopride, or placebo in a double blind, randomised fashion. The transit test was performed over the last 48 hours. RESULTS There were significant accelerations of overall colonic transit at 4, 8, 24, and 48 hours (p<0.05) and proximal colonic emptying t 1/2 (p<0.05). The 0.5, 2, and 4 mg doses of prucalopride were almost equally effective and accelerated colonic transit compared with placebo. Prucalopride did not significantly alter gastric emptying (p>0.5) or small bowel transit (overall p=0.12). The medication appeared to be well tolerated during the seven day treatment of healthy subjects. CONCLUSION Prucalopride accelerates colonic transit, partly by stimulating proximal colonic emptying, but does not alter gastric or small bowel transit in healthy human subjects. Prucalopride deserves further study in patients with constipation.