Upregulation of polycistronic microRNA-143 and microRNA-145 in colonocytes suppresses colitis and inflammation-associated colon cancer

Because ADAM17 promotes colonic tumorigenesis, we investigated potential miRNAs regulating ADAM17; and examined effects of diet and tumorigenesis on these miRNAs. We also examined pre-miRNA processing and tumour suppressor roles of several of these miRNAs in experimental colon cancer. Using TargetScan, miR-145, miR-148a, and miR-152 were predicted to regulate ADAM17. miR-143 was also investigated as miR-143 and miR-145 are co-transcribed and associated with decreased tumour growth. HCT116 colon cancer cells (CCC) were co-transfected with predicted ADAM17-regulating miRNAs and luciferase reporters controlled by ADAM17-3'UTR. Separately, pre-miR-143 processing by colonic cells was measured. miRNAs were quantified by RT-PCR. Tumours were induced with AOM/DSS in WT and transgenic mice (Tg) expressing pre-miR-143/miR-145 under villin promoter. HCT116 transfection with miR-145, -148a or -152, but not scrambled miRNA inhibited ADAM17 expression and luciferase activity. The latter was suppressed by mutations in ADAM17-3'UTR. Lysates from colonocytes, but not CCC, processed pre-miR-143 and mixing experiments suggested CCC lacked a competency factor. Colonic miR-143, miR-145, miR-148a, and miR-152 were downregulated in tumours and more moderately by feeding mice a Western diet. Tg mice were resistant to DSS colitis and had significantly lower cancer incidence and tumour multiplicity. Tg expression blocked up-regulation of putative targets of miR-143 and miR-145, including ADAM17, K-Ras, XPO5, and SET. miR-145, miR-148a, and miR-152 directly suppress colonocyte ADAM17 and are down-regulated in colon cancer. This is the first direct demonstration of tumour suppressor roles for miR-143 and miR-145 in an in vivo model of colonic tumorigenesis.

Losartan and Vitamin D Inhibit Colonic Tumor Development in a Conditional Apc-Deleted Mouse Model of Sporadic Colon Cancer

Colorectal cancer is a leading cause of cancer deaths. The renin-angiotensin system (RAS) is upregulated in colorectal cancer, and epidemiologic studies suggest RAS inhibitors reduce cancer risk. Because vitamin D (VD) receptor negatively regulates renin, we examined anticancer efficacy of VD and losartan (L), an angiotensin receptor blocker. Control Apc^+/LoxP mice and tumor-forming Apc^+/LoxP Cdx2P-Cre mice were randomized to unsupplemented Western diet (UN), or diets supplemented with VD, L, or VD+L, the latter to assess additive or synergistic effects. At 6 months, mice were killed. Plasma Ca²⁺, 25(OH)D3, 1α, 25(OH)2D3, renin, and angiotensin II (Ang II) were quantified. Colonic transcripts were assessed by qPCR and proteins by immunostaining and blotting. Cancer incidence and tumor burden were significantly lower in Cre+ VD and Cre+ L, but not in the Cre+ VD+L group. In Apc^+/LoxP mice, VD increased plasma 1,25(OH)2D3 and colonic VDR. In Apc^+/LoxP-Cdx2P-Cre mice, plasma renin and Ang II, and colonic tumor AT1, AT2, and Cyp27B1 were increased and VDR downregulated. L increased, whereas VD decreased plasma renin and Ang II in Cre+ mice. VD or L inhibited tumor development, while exerting differential effects on plasma VD metabolites and RAS components. We speculate that AT1 is critical for tumor development, whereas RAS suppression plays a key role in VD chemoprevention. When combined with L, VD no longer increases active VD and colonic VDR in Cre- mice nor suppresses renin and Ang II in Cre+ mice, likely contributing to lack of chemopreventive efficacy of the combination.

Perceptions of risk and therapy among patients with Barrett's esophagus: a patient survey study

Nondysplastic Barrett's esophagus has a risk of progression to esophageal adenocarcinoma as low as 0.18-0.3% per person per year, and low-grade dysplasia as low as 0.5%. While adherence to guidelines and selection of management options varies, little is known about what modifies patient decision-making. This study aims to evaluate and identify factors that influence patient perceptions of risk and decisions about management. An independently developed and piloted survey was administered to patients at an academic hospital. Risk perception and desire for therapy were assessed using a standard reference gamble paradigm, and responses were stratified based on patient and disease characteristics. Data were analyzed with Student's t and chi-squared tests. A total of 42 of 50 patients with Barrett's esophagus and no prior endoscopic therapy participated (84% response; 76% nondysplastic Barrett's esophagus, 22% low-grade dysplasia, 2% indeterminate for dysplasia; mean age 61 years, 29% female). On average, patients perceived their risk of developing esophageal adenocarcinoma in the next year, 10 years and lifetime as 6, 14, and 19%, respectively. Nearly half viewed their lifetime risk of developing esophageal adenocarcinoma to be the same or higher than diabetes, heart disease, or colon cancer. Although 92% of patients felt surveillance beneficial, only 54% believed endoscopic therapy to be effective in most or all cases. As many as 83% of patients were willing to undergo endoscopic therapy with a hypothetical success rate as low as 70%, and a majority (64%) accepted complication rates up to 30%. Compared to patients with low risk perception of developing esophageal adenocarcinoma, those with high risk perception more often believed their risk for developing esophageal adenocarcinoma was greater than diabetes (p = 0.04) or colon cancer (p = 0.002). Those with lifetime low risk perception were less likely to accept modest complication rates (<10%) of therapy (P < 0.05). Age, gender, degree of dysplasia, lifetime endoscopies and duration of symptoms had no impact on perceived effectiveness of surveillance or therapy, and did not correlate with desire for treatment at varying levels of risk and effectiveness. Patients with Barrett's esophagus overestimate their risk of developing esophageal adenocarcinoma and will accept low success rates and high risk of complications to undergo endoscopic therapy. Baseline risk perception correlates with the desire for endoscopic therapy.

Risk of infection transmission in curvilinear array echoendoscopes: results of a prospective reprocessing and culture registry

BACKGROUND AND AIMS

The complex design of the elevator mechanism in duodenoscopes has been recognized as a challenge for disinfection and recently implicated as a potential source of persistent bacterial contamination. Curvilinear array (CLA) echoendoscopes also have an elevator mechanism; however, there are no recommendations or data regarding the risk of persistent bacterial contamination of echoendoscopes. Here we hoped to determine the yield of microbial growth with routine bacterial surveillance cultures of reprocessed CLA echoendoscopes.

METHODS

Beginning in February 2015 to February 2016, CLA echoendoscopes at a single tertiary care center underwent prospective bacterial surveillance cultures after reprocessing. Any growth of gram-negative bacilli was considered to be critical. Echoendoscopes with a positive result underwent quarantine followed by repeat disinfection and culture.

RESULTS

During the study period, 540 cultures were obtained; 521 (96.5%) were primary cultures obtained from 18 CLA echoendoscopes. Twenty-two primary cultures (4.2%) were positive for gram-negative bacilli after high-level disinfection reprocessing. Eleven different bacteria were isolated: Klebsiella pneumoniae, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Sphingomonas paucimobilis, Acinetobacter baumanii, Enterobacter cloacae, Hafnia alvei, Pseudomonas putida, and Stenotrophomonas maltophilia. Antibiotic sensitivity data on 19 of 24 bacteria (79.2%) isolated from positive primary cultures revealed no documented cases of carbapenem-resistant enterobacteriaceae, cephalosporin-resistant-Klebsiella, or multidrug-resistant Acinetobacter. There have been no documented cases of patient-to-patient transmission.

CONCLUSIONS

After following standard high-level disinfection and reprocessing, CLA echoendoscopes can remain culture positive for high-concern organisms. Recommendations regarding infection risk should take into consideration elevator-containing echoendoscopes in addition to duodenoscopes to ensure patient safety and endoscope reprocessing efficacy.

Safety and efficacy of EMR for sporadic, nonampullary duodenal adenomas: a single U.S. center experience (with video)

BACKGROUND AND AIMS

EMR is increasingly used for resection of sporadic, nonampullary duodenal adenomas (SNDAs), but there are no guidelines for the management of these lesions. The aims of this study were to evaluate the safety and efficacy of EMR exclusively for SNDAs and to determine the factors predictive of outcomes.

METHODS

We performed a retrospective review of patients with SNDAs referred for endoscopic therapy from 2006 to 2013. The outcomes studied were successful endoscopic resection, major adverse events, early and late recurrences, and clinical remission.

RESULTS

Sixty-eight patients with SNDAs were included and 51 (75%) underwent EMR. The mean adenoma size was 22.0 ± 8.9 mm. Successful resection was achieved in 49 of 51 patients (96.1%), and major adverse events were noted in 8 of 51 patients (15.7%). Early and late recurrences were noted in 25.6% and 5.2% of patients, respectively, and were treated endoscopically. Clinical remission was achieved in 89.7% of patients after a median follow-up of 15 months. Presence of villous histology was associated with increased recurrence (P = .019), but no association of recurrence was noted with other endoscopic features or resection technique. Large adenoma size (P = .0057) and need for intraprocedural hemostasis (P = .006) were associated with increased adverse events, but no association of adverse events was noted with location or resection technique.

CONCLUSIONS

Large duodenal adenomas can be effectively managed with EMR at a referral center with experienced endoscopists. However, EMR has a significant recurrence rate, especially early recurrence, and the risk of adverse events is not negligible. Endoscopic therapy is successful in managing recurrent adenomas.

Post-ablation surveillance in Barrett's esophagus: A review of the literature

Barrett’s esophagus (BE) is a pre-malignant condition affecting up to 15% of patients with gastroesophageal reflux disease. Neoplastic Barrett’s mucosa is defined as harboring high grade dysplasia or intra-mucosal cancer, and carries a high risk of progression to esophageal adenocarcinoma. The rising incidence of Barrett’s lesions along with the high morbidity of surgical approaches has led to the development of numerous validated endoscopic techniques capable of eradicating neoplastic mucosa in a minimally invasive manner. While there has been widespread adoption of these techniques, less is known about optimal surveillance intervals in the post-therapy period. This is due in part to limitations in current surveillance methods, questions about durability of treatment response and the risk of subendothelial progression. As we are now able to achieve organ sparing eradication of superficial neoplasia in BE, we need to also then focus our attention on how best to manage these patients after eradication is achieved. Implementing optimal surveillance practices requires additional understanding of the biology of the disease, appreciation of the limits of current tools and treatments, and exploration of the role of adjunctive technologies. The aim of this article is to provide a comprehensive review of current literature surrounding post-ablation surveillance in neoplastic BE.

Needle-based confocal endomicroscopy for pancreatic cysts: the current agreement in interpretation

BACKGROUND AND AIMS

Diagnosis of pancreatic cystic lesions (PCLs) remains challenging. EUS with FNA is limited by sampling error and nondiagnostic cytology. Needle-based confocal laser endomicroscopy (nCLE) performed during EUS can be used to improve diagnostic yield via FNA by providing in vivo histology of PCLs. However, the interobserver agreement (IOA) of nCLE of PCLs has yet to be studied.

METHODS

Fifteen deidentified nCLE video clips of PCLs were sent to 6 interventional endoscopists at 5 institutions. Six variables were assessed for IOA: presence or absence of (1) vessels, (2) villi, (3) dark clumps, (4) reticular pattern, (5) acinar cells pattern, and (6) debris. PCL interpretation was categorized as mucinous, serous, pseudocyst, malignant, or indeterminate and final diagnosis as benign, malignant, or indeterminate.

RESULTS

IOA ranged from "poor" to "fair." The K statistics were -.04 (SE = .05) for vessels, .16 (SE = .07) for villi, .22 (SE = .06) for dark clumps, .13 (SE = .06) for reticular pattern, .14 (SE = .06) for acinar cells pattern, .06 (SE = .06) for debris, .15 (SE = .03) for interpretation, .13 (SE = .05) for final diagnosis, and .19 (SE = .05) for image quality. The final diagnosis was malignant (10), benign (13), and indeterminate (2). The mean accuracy of the observers was 46%, with the lowest being 20% and highest being 67%.

CONCLUSIONS

The IOA and accuracy for PCL diagnosis were low. The results of this study support the need to identify and validate imaging criteria to determine whether nCLE has diagnostic value for pancreatic pathology. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02166086.).

Acquisition of Portal Venous Circulating Tumor Cells From Patients With Pancreaticobiliary Cancers by Endoscopic Ultrasound

BACKGROUND & AIMS

Tumor cells circulate in low numbers in peripheral blood; their detection is used predominantly in metastatic disease. We evaluated the feasibility and safety of sampling portal venous blood via endoscopic ultrasound (EUS) to count portal venous circulating tumor cells (CTCs), compared with paired peripheral CTCs, in patients with pancreaticobiliary cancers (PBCs).

METHODS

In a single-center cohort study, we evaluated 18 patients with suspected PBCs. Under EUS guidance, a 19-gauge EUS fine needle was advanced transhepatically into the portal vein and as many as four 7.5-mL aliquots of blood were aspirated. Paired peripheral blood samples were obtained. Epithelial-derived CTCs were sorted magnetically based on expression of epithelial cell adhesion molecules; only those with a proper morphology and found to be CD45 negative and positive for cytokeratins 8, 18, and/or 19 and 4',6-diamidino-2-phenylindole were considered to be CTCs. For 5 samples, CTCs also were isolated by flow cytometry and based on CD45 depletion. ImageStream was used to determine the relative protein levels of P16, SMAD4, and P53. DNA was extracted from CTCs for sequencing of select KRAS codons.

RESULTS

There were no complications from portal vein blood acquisition. We detected CTCs in portal vein samples from all 18 patients (100%) vs peripheral blood samples from only 4 patients (22.2%). Patients with confirmed PBCs had a mean of 118.4 ± 36.8 CTCs/7.5 mL portal vein blood, compared with a mean of 0.8 ± 0.4 CTCs/7.5 mL peripheral blood (P < .01). The 9 patients with nonmetastatic, resectable, or borderline-resectable PBCs had a mean of 83.2 CTCs/7.5 mL portal vein blood (median, 62.0 CTCs/7.5 mL portal vein blood). In a selected patient, portal vein CTCs were found to carry the same mutations as those detected in a metastatic lymph node and expressed similar levels of P16, SMAD4, and P53 proteins.

CONCLUSIONS

It is feasible and safe to collect portal venous blood from patients undergoing EUS. We identified CTCs in all portal vein blood samples from patients with PBCs, but less than 25% of peripheral blood samples. Portal vein CTCs can be used for molecular characterization of PBCs and share features of metastatic tissue. This technique might be used to study the pathogenesis and progression of PBCs, as well as a diagnostic or prognostic tool to stratify risk of cancer recurrence or developing metastases.

Colon cancer and the epidermal growth factor receptor: Current treatment paradigms, the importance of diet, and the role of chemoprevention

Colorectal cancer represents the third most common and the second deadliest type of cancer for both men and women in the United States claiming over 50000 lives in 2014. The 5-year survival rate for patients diagnosed with metastatic colon and rectal cancer is < 15%. Early detection and more effective treatments are urgently needed to reduce morbidity and mortality of patients afflicted with this disease. Here we will review the risk factors and current treatment paradigms for colorectal cancer, with an emphasis on the role of chemoprevention as they relate to epidermal growth factor receptor (EGFR) blockade. We will discuss how various EGFR ligands are upregulated in the presence of Western diets high in saturated and N-6 polyunsaturated fats. We will also outline the various mechanisms of EGFR inhibition that are induced by naturally occurring chemopreventative agents such as ginseng, green tea, and curcumin. Finally, we will discuss the current role of targeted chemotherapy in colon cancer and outline the limitations of our current treatment options, describing mechanisms of resistance and escape.

Use of probe-based confocal laser endomicroscopy (pCLE) in gastrointestinal applications. A consensus report based on clinical evidence

BACKGROUND

Probe-based confocal laser endomicroscopy (pCLE) provides microscopic imaging during an endoscopic procedure. Its introduction as a standard modality in gastroenterology has brought significant progress in management strategies, affecting many aspects of clinical care and requiring standardisation of practice and training.

OBJECTIVE

This study aimed to provide guidance on the standardisation of its practice and training in Barrett's oesophagus, biliary strictures, colorectal lesions and inflammatory bowel diseases.

METHODS

Initial statements were developed by five group leaders, based on the available clinical evidence. These statements were then voted and edited by the 26 participants, using a modified Delphi approach. After two rounds of votes, statements were validated if the threshold of agreement was higher than 75%.

RESULTS

Twenty-six experts participated and, among a total of 77 statements, 61 were adopted (79%) and 16 were rejected (21%). The adoption of each statement was justified by the grade of evidence.

CONCLUSION

pCLE should be used to enhance the diagnostic arsenal in the evaluation of these indications, by providing microscopic information which improves the diagnostic performance of the physician. In order actually to implement this technology in the clinical routine, and to ensure good practice, standardised initial and continuing institutional training programmes should be established.

The renin-angiotensin system mediates EGF receptor-vitamin d receptor cross-talk in colitis-associated colon cancer

PURPOSE

We previously showed that EGF receptor (EGFR) promotes tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS) model, whereas vitamin D suppresses tumorigenesis. EGFR-vitamin D receptor (VDR) interactions, however, are incompletely understood. Vitamin D inhibits the renin-angiotensin system (RAS), whereas RAS can activate EGFR. We aimed to elucidate EGFR-VDR cross-talk in colorectal carcinogenesis.

EXPERIMENTAL DESIGN

To examine VDR-RAS interactions, we treated Vdr(+/+) and Vdr(-/-) mice with AOM/DSS. Effects of VDR on RAS and EGFR were examined by Western blotting, immunostaining, and real-time PCR. We also examined the effect of vitamin D3 on colonic RAS in Vdr(+/+) mice. EGFR regulation of VDR was examined in hypomorphic Egfr(Waved2) (Wa2) and Egfr(wild-type) mice. Angiotensin II (Ang II)-induced EGFR activation was studied in cell culture.

RESULTS

Vdr deletion significantly increased tumorigenesis, activated EGFR and β-catenin signaling, and increased colonic RAS components, including renin and angiotensin II. Dietary VD3 supplementation suppressed colonic renin. Renin was increased in human colon cancers. In studies in vitro, Ang II activated EGFR and stimulated colon cancer cell proliferation by an EGFR-mediated mechanism. Ang II also activated macrophages and colonic fibroblasts. Compared with tumors from Egfr(Waved2) mice, tumors from Egfr(wild-type) mice showed upregulated Snail1, a suppressor of VDR, and downregulated VDR.

CONCLUSIONS

VDR suppresses the colonic RAS cascade, limits EGFR signals, and inhibits colitis-associated tumorigenesis, whereas EGFR increases Snail1 and downregulates VDR in colonic tumors. Taken together, these results uncover a RAS-dependent mechanism mediating EGFR and VDR cross-talk in colon cancer.

Early diagnosis and management of esophageal and gastric cancer

Esophageal and gastric cancers have high mortality rates secondary to the late presentation of most patients at advanced stages. Improved survival is achievable when the disease is confined to the more superficial mucosal layers and treated. This review will focus on the detection, screening, staging, endoscopic treatment, and surveillance of early upper gastrointestinal cancer - squamous cell carcinoma of the esophagus, esophageal adenocarcinoma, and gastric adenocarcinoma.

American ginseng suppresses Western diet-promoted tumorigenesis in model of inflammation-associated colon cancer: role of EGFR

Background

Western diets increase colon cancer risk. Epidemiological evidence and experimental studies suggest that ginseng can inhibit colon cancer development. In this study we asked if ginseng could inhibit Western diet (20% fat) promoted colonic tumorigenesis and if compound K, a microbial metabolite of ginseng could suppress colon cancer xenograft growth.

Methods

Mice were initiated with azoxymethane (AOM) and, two weeks later fed a Western diet (WD, 20% fat) alone, or WD supplemented with 250-ppm ginseng. After 1 wk, mice received 2.5% dextran sulfate sodium (DSS) for 5 days and were sacrificed 12 wks after AOM. Tumors were harvested and cell proliferation measured by Ki67 staining and apoptosis by TUNEL assay. Levels of EGF-related signaling molecules and apoptosis regulators were determined by Western blotting. Anti-tumor effects of intraperitoneal compound K were examined using a tumor xenograft model and compound K absorption measured following oral ginseng gavage by UPLC-mass spectrometry. Effects of dietary ginseng on microbial diversity were measured by analysis of bacterial 16S rRNA.

Results

Ginseng significantly inhibited colonic inflammation and tumorigenesis and concomitantly reduced proliferation and increased apoptosis. The EGFR cascade was up-regulated in colonic tumors and ginseng significantly reduced EGFR and ErbB2 activation and Cox-2 expression. Dietary ginseng altered colonic microbial diversity, and bacterial suppression with metronidazole reduced serum compound K following ginseng gavage. Furthermore, compound K significantly inhibited tumor xenograft growth.

Conclusions

Ginseng inhibited colonic inflammation and tumorigenesis promoted by Western diet. We speculate that the ginseng metabolite compound K contributes to the chemopreventive effects of this agent in colonic tumorigenesis.