Christina Vorvis

MicroRNA214 Is Associated With Progression of Ulcerative Colitis, and Inhibition Reduces Development of Colitis and Colitis-Associated Cancer in Mice

BACKGROUND & AIMS Persistent activation of the inflammatory response contributes to the development of inflammatory bowel diseases, which increase the risk of colorectal cancer. We aimed to identify microRNAs that regulate inflammation during the development of ulcerative colitis (UC) and progression to colitis-associated colon cancer (CAC). METHODS We performed a quantitative polymerase chain reaction analysis to measure microRNAs in 401 colon specimens from patients with UC, Crohns disease, irritable bowel syndrome, sporadic colorectal cancer, or CAC, as well as subjects without these disorders (controls); levels were correlated with clinical features and disease activity of patients. Colitis was induced in mice by administration of dextran sodium sulfate (DSS), and carcinogenesis was induced by addition of azoxymethane; some mice also were given an inhibitor of microRNA214 (miR214). RESULTS A high-throughput functional screen of the human microRNAome found that miR214 regulated the activity of nuclear factor-κB. Higher levels of miR214 were detected in colon tissues from patients with active UC or CAC than from patients with other disorders or controls and correlated with disease progression. Bioinformatic and genome-wide profile analyses showed that miR214 activates an inflammatory response and is amplified through a feedback loop circuit mediated by phosphatase and tensin homolog (PTEN) and PDZ and LIM domain 2 (PDLIM2). Interleukin-6 induced signal transducer and activator of transcription 3 (STAT3)-mediated transcription of miR214. A miR214 chemical inhibitor blocked this circuit and reduced the severity of DSS-induced colitis in mice, as well as the number and size of tumors that formed in mice given azoxymethane and DSS. In fresh colonic biopsy specimens from patients with active UC, the miR214 inhibitor reduced inflammation by increasing levels of PDLIM2 and PTEN. CONCLUSIONS Interleukin-6 up-regulates STAT3-mediated transcription of miR214 in colon tissues, which reduces levels of PDLIM2 and PTEN, increases phosphorylation of AKT, and activates nuclear factor-κB. The activity of this circuit correlates with disease activity in patients with UC and progression to colorectal cancer.

Functional microRNA high throughput screening reveals miR-9 as a central regulator of liver oncogenesis by affecting the PPARA-CDH1 pathway.

BackgroundHepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths, reflecting the aggressiveness of this type of cancer and the absence of effective therapeutic regimens. MicroRNAs have been involved in the pathogenesis of different types of cancers, including liver cancer. Our aim was to identify microRNAs that have both functional and clinical relevance in HCC and examine their downstream signaling effectors.MethodsMicroRNA and gene expression levels were measured by quantitative real-time PCR in HCC tumors and controls. A TargetScan algorithm was used to identify miR-9 downstream direct targets.ResultsA high-throughput screen of the human microRNAome revealed 28 microRNAs as regulators of liver cancer cell invasiveness. MiR-9, miR-21 and miR-224 were the top inducers of HCC invasiveness and also their expression was increased in HCC relative to control liver tissues. Integration of the microRNA screen and expression data revealed miR-9 as the top microRNA, having both functional and clinical significance. MiR-9 levels correlated with HCC tumor stage and miR-9 overexpression induced SNU-449 and HepG2 cell growth, invasiveness and their ability to form colonies in soft agar. Bioinformatics and 3′UTR luciferase analyses identified E-cadherin (CDH1) and peroxisome proliferator-activated receptor alpha (PPARA) as direct downstream effectors of miR-9 activity. Inhibition of PPARA suppressed CDH1 mRNA levels, suggesting that miR-9 regulates CDH1 expression directly through binding in its 3′UTR and indirectly through PPARA. On the other hand, miR-9 inhibition of overexpression suppressed HCC tumorigenicity and invasiveness. PPARA and CDH1 mRNA levels were decreased in HCC relative to controls and were inversely correlated with miR-9 levels.ConclusionsTaken together, this study revealed the involvement of the miR-9/PPARA/CDH1 signaling pathway in HCC oncogenesis.

Developments in miRNA gene signaling pathways in pancreatic cancer.

Pancreatic cancer is a devastating malignancy that ranks as the fourth leading cause of cancer-related deaths worldwide. Dismal prognosis is mainly attributable to limited knowledge of the molecular pathogenesis of the disease. miRNAs have been found to be deregulated in pancreatic cancer, affecting several steps of initiation and aggressiveness of the disease by regulating important signaling pathways, such as the KRAS and Notch pathways. Moreover, the effect of miRNAs on regulating cell cycle events and expression of transcription factors has gained a lot of attention. Recent studies have highlighted the application of miRNAs as biomarkers and therapeutic tools. The current review focuses on latest advances with respect to the roles of miRNAs in pancreatic ductal adenocarcinoma associated signaling pathways and miRNA-based therapeutics.

MKAD-21 suppresses the oncogenic activity of the miR-21/PPP2R2A/ERK molecular network in bladder cancer

Bladder cancer represents a disease associated with significant morbidity and mortality. MiR-21 has been found to have oncogenic activity in multiple cancers, including bladder cancer, whereas inhibition of its expression suppresses tumor growth. Here, we examine the molecular network regulated by miR-21 in bladder cancer and evaluate the effects of i.v. and i.p. administration of a novel miR-21 chemical inhibitor in vivo. LNA miR-21 reduced the oncogenic potential of bladder cancer cells, whereas the MKAD-21 chemically modified antisense oligo against miR-21 dose-dependently blocked xenograft growth. I.v. administration of LNA miR-21 was more effective in suppressing tumor growth than was i.p. administration. Integration of computational and transcriptomic analyses in a panel of 28 bladder cancer lines revealed a 15-gene signature that correlates with miR-21 levels. Protein Phosphatase 2 Regulatory Subunit Balpha (PPP2R2A) was one of these 15 genes and was experimentally validated as a novel miR-21 direct target gene. Gene network and molecular analyses showed that PPP2R2A is a potent negative regulator of the ERK pathway activation and bladder cancer cell proliferation. Importantly, we show that PPP2R2A acts as a mediator of miR-21–induced oncogenic effects in bladder cancer. Integrative analysis of human bladder cancer tumors and a large panel of human bladder cancer cell lines revealed a novel 15-gene signature that correlates with miR-21 levels. Importantly, we provide evidence that PPP2R2A represents a new miR-21 direct target and regulator of the ERK pathway and bladder cancer cell growth. Furthermore, i.v. administration of the MKAD-21 inhibitor effectively suppressed tumor growth through regulation of the PPP2R2A–ERK network in mice. Mol Cancer Ther; 17(7); 1430–40. ©2018 AACR.

347 Targeting a microRNA for the Therapy of Colitis-Associated Colorectal Cancer

Background/Aim: Mucosal healing (MH) at endoscopy is a major therapeutic goal in ulcerative colitis (UC). Endoscopy, however, is invasive, time consuming and uncomfortable. Computed tomography colonography (CTC) has emerged as a noninvasive screening procedure for colorectal neoplasia but radiation exposure is a major concern if applied to patients with UC. We aimed to examine ultra-low dose CTC (uCTC) for evaluating mucosal inflammation in patients with UC. Methods: Patients with UC underwent colonoscopy and uCTC acquired with low dose at 75 mAs or ultra-low dose at 5 mAs levels on the same day. As bowel preparation, patients took low residue diets on the previoursday and 1.8L of isotonic magnesium solution on the day. CTC images were evaluated for UC, in which selected valuables (loss of colonic haustra, luminal narrowing, bowel wall thickness, mural hyperenhancement and mesenteric hyper-vascularity in both air images or multiplanar reconstruction (MPR) images) were scored from 0 to 1 in the worst affected segment of colon, to create a novel uCTC score from 0 to 5. Endoscopic severity was evaluated by Mayo Clinic endoscopy sub-score (eMCS, 0-3) and the two score were correlated. Results: In 90 patients the median uCTC score was 3.56 (range 0-5) and eMCS 1.89 (range 0-3). The uCTC score correlated with eMCS (r = 0.727, p< 0.001). The CTC score for each Mayo e-score were as follows (mean±SD): score 0, 0.77±0.77; 1, 2.56±1.40; 2, 3.69±1.69; 3, 4.83±0.34. The uCTC score showed significant differences between endoscopic activity and MH (eMCS 0 vs 1 P<0.001; 1 vs 2 or 3, P<0.01 and <0.001, respectively). Furthermore, uCTC air images alone revealed a significant relationship with eMCS, even with ultra-low dose CTC at 5 mAs levels. Conclusion: uCTC may be a non-invasive tool to assess mucosal activity in UC and may be a technique to determine MH. Ultra-low dose CTC resolves concern about radiation exposure.