Allison L. Yang

Increased susceptibility of chronic ulcerative colitis-induced carcinoma development in DNA repair enzyme Ogg1 deficient mice †

Ogg1 DNA repair enzyme recognizes and excises oxidative stress‐caused 8‐hydroxyl‐deoxyguanosine (8‐OHdG) from GC base‐pairs. Ogg1 knockout mice are phenotypically normal, but exhibit elevated levels of 8‐OHdG in nuclear and mitochondrial DNA, as well as moderately elevated mutagenesis and spontaneous lung tumors and UV‐induced skin tumors. To elucidate the mechanistic role of inflammation‐caused oxidative stress in carcinogenesis, the development of chronic ulcerative colitis (UC)‐induced carcinoma in Ogg1 knockout mice was studied using a dextran sulfate sodium (DSS)‐induced UC model without the use of a carcinogen. Ogg1 (−/−), Ogg1 (+/−), and wild type C57BL/6 mice were subjected to long‐term, cyclic DSS treatment to induce chronic UC and carcinogenesis. In wild type C57BL/6 control mice after 15 cycles of DSS treatment, colorectal adenocarcinoma incidence was 24.1% (7/29 mice), with a tumor volume of 27.9 ± 5.2 mm3. Ogg1 (−/−) mice showed significantly increased adenocarcinoma development in the colon with a tumor incidence of 57.1% (12 of 21 mice, P < 0.05) and a tumor volume of 35.1 ± 6.1 mm3. Ogg1 mice (+/−) also exhibited significantly increased tumor development in the colon with a tumor incidence of 50.0% (13/26 mice) and a tumor volume of 29.1 ± 7.2 mm3. Histopathologic analyses revealed that colorectal tumors were well‐differentiated tubular adenocarcinomas or mucinous carcinoma and adjacent colonic mucosa showed mild to moderate chronic UC. Using immunohistochemical approaches, Ogg1 (−/−) and (+/−) mice exhibited similar numbers and staining intensities of macrophages in UC areas as seen in Ogg1 (+/+) mice, but markedly increased numbers and staining intensities of 8‐OHdG positive inflammatory and epithelial cells. These results provide important evidence on the relationship between inflammation‐caused oxidative stress, DNA repair enzyme Ogg1, and carcinogenesis.

Soluble Epoxide Hydrolase Gene Deficiency or Inhibition Attenuates Chronic Active Inflammatory Bowel Disease in IL-10(−/−) Mice

BackgroundSoluble epoxide hydrolase (sEH) metabolizes anti-inflammatory epoxyeicosatrienoic acids (EETs) into their much less active dihydroxy derivatives dihydroxyeicosatrienoic acids. Thus, targeting sEH would be important for inflammation.AimsTo determine whether knockout or inhibition of sEH would attenuate the development of inflammatory bowel disease (IBD) in a mouse model of IBD in IL-10(−/−) mice.MethodsEither the small molecule sEH inhibitor trans/-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB) or sEH knockout mice were used in combination with IL-10(−/−) mice. t-AUCB was administered to mice in drinking fluid. Extensive histopathologic, immunochemical, and biochemical analyses were performed to evaluate effect of sEH inhibition or deficiency on chronic active inflammation and related mechanism in the bowel.ResultsCompared to IL-10 (−/−) mice, sEH inhibition or sEH deficiency in IL-10(−/−) mice resulted in significantly lower incidence of active ulcer formation and transmural inflammation, along with a significant decrease in myeloperoxidase-labeled neutrophil infiltration in the inflamed bowel. The levels of IFN-γ, TNF-α, and MCP-1, as well VCAM-1 and NF-kB/IKK-α signals were significantly decreased as compared to control animals. Moreover, an eicosanoid profile analysis revealed a significant increase in the ratio of EETs/DHET and EpOME/DiOME, and a slightly down-regulation of inflammatory mediators LTB4 and 5-HETE.ConclusionThese results indicate that sEH gene deficiency or inhibition reduces inflammatory activities in the IL-10 (−/−) mouse model of IBD, and that sEH inhibitor could be a highly potential in the treatment of IBD.

Sulindac inhibits pancreatic carcinogenesis in LSL-KrasG12D-LSL-Trp53R172H-Pdx-1-Cre mice via suppressing aldo-keto reductase family 1B10 (AKR1B10)

Sulindac has been identified as a competitive inhibitor of aldo-keto reductase 1B10 (AKR1B10), an enzyme that plays a key role in carcinogenesis. AKR1B10 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and exhibits lipid substrate specificity, especially for farnesyl and geranylgeranyl. There have been no studies though showing that the inhibition of PDAC by sulindac is via inhibition of AKR1B10, particularly the metabolism of farnesyl/geranylgeranyl and Kras protein prenylation. To determine the chemopreventive effects of sulindac on pancreatic carcinogenesis, 5-week-old LSL-Kras(G12D)-LSL-Trp53(R172H)-Pdx-1-Cre mice (Pan(kras/p53) mice) were fed an AIN93M diet with or without 200 p.p.m. sulindac (n = 20/group). Kaplan-Meier survival analysis showed that average animal survival in Pan(kras/p53) mice was 143.7 ± 8.8 days, and average survival with sulindac was increased to 168.0 ± 8.8 days (P < 0.005). Histopathological analyses revealed that 90% of mice developed PDAC, 10% with metastasis to the liver and lymph nodes. With sulindac, the incidence of PDAC was reduced to 56% (P < 0.01) and only one mouse had lymph node metastasis. Immunochemical analysis showed that sulindac significantly decreased Ki-67-labeled cell proliferation and markedly reduced the expression of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Raf and mitogen-activated protein kinase kinase 1 and 2. In in vitro experiments with PDAC cells from Pan(kras/p53) mice, sulindac exhibited dose-dependent inhibition of AKR1B10 activity. By silencing AKR1B10 expression through small interfering RNA or by sulindac treatment, these in vitro models showed a reduction in Kras and human DNA-J homolog 2 protein prenylation, and downregulation of phosphorylated C-raf, ERK1/2 and MEK1/2 expression. Our results demonstrate that sulindac inhibits pancreatic carcinogenesis by the inhibition of Kras protein prenylation by targeting AKR1B10.

Reduction of inflammatory bowel disease-induced tumor development in IL-10 knockout mice with soluble epoxide hydrolase gene deficiency

Soluble epoxide hydrolase (sEH) quickly inactivates anti‐inflammatory epoxyeicosatrienoic acids (EETs) by converting them to dihydroxyeicosatrienoic acids (DHETs). Inhibition of sEH has shown effects against inflammation, but little is studied about the role of sEH in inflammatory bowel disease (IBD) and its induced carcinogenesis. In the present study, the effect of sEH gene deficiency on the development of IBD‐induced tumor development was determined in IL‐10 knockout mice combined with sEH gene deficiency. Tumor development in the bowel was examined at the age of 25 wk for male mice and 35 wk for female mice. Compared to IL‐10(−/−) mice, sEH (−/−)/IL‐10(−/−) mice exhibited a significant decrease of tumor multiplicity (2 ± 0.9 tumors/mouse vs. 1 ± 0.3 tumors/mouse) and tumor size (344.55 ± 71.73 mm3 vs. 126.94 ± 23.18 mm3), as well as a marked decrease of precancerous dysplasia. The significantly lower inflammatory scores were further observed in the bowel in sEH(−/−)/IL‐10(−/−) mice as compared to IL‐10(−/−) mice, including parameters of inflammation‐involved area (0.70 ± 0.16 vs. 1.4 ± 0.18), inflammation cell infiltration (1.55 ± 0.35 vs. 2.15 ± 0.18), and epithelial hyperplasia (0.95 ± 0.21 vs. 1.45 ± 0.18), as well as larger ulcer formation. qPCR and Western blotting assays demonstrated a significant downregulation of cytokines/chemokines (TNF‐α, MCP‐1, and IL‐12, 17, and 23) and NF‐κB signals. Eicosanoid acid metabolic profiling revealed a significant increase of ratios of EETs to DHETs and EpOMEs to DiOMEs. These results indicate that sEH plays an important role in IBD and its‐induced carcinogenesis and could serve as a highly potential target of chemoprevention and treatment for IBD.

Atorvastatin inhibits pancreatic carcinogenesis and increases survival in LSL‐KrasG12D‐LSL‐Trp53R172H‐Pdx1‐Cre mice

There are several studies supporting the role of HMG‐CoA reductase inhibitors such as atorvastatin against carcinogenesis, in which inhibiting the generation of prenyl intermediates involved in protein prenylation plays the crucial role. Mutation of Kras gene is the most common genetic alteration in pancreatic cancer and the Ras protein requires prenylation for its membrane localization and activity. In the present study, the effectiveness of atorvastatin against pancreatic carcinogenesis and its effect on protein prenylation were determined using the LSL‐KrasG12D‐LSL‐Trp53R172H‐Pdx1‐Cre mouse model (called Pankras/p53 mice). Five‐week‐old Pankras/p53 mice were fed either an AIN93M diet or a diet supplemented with 100 ppm atorvastatin. Kaplan–Meier survival analysis with Log‐Rank test revealed a significant increase in survival in mice fed 100 ppm atorvastatin (171.9 ± 6.2 d) compared to the control mice (144.9 ± 8.4 d, P < 0.05). Histologic and immunohistochemical analysis showed that atorvastatin treatment resulted in a significant reduction in tumor volume and Ki‐67‐labeled cell proliferation. Mechanistic studies on primary pancreatic tumors and the cultured murine pancreatic carcinoma cells revealed that atorvastatin inhibited prenylation in several key proteins, including Kras protein and its activities, and similar effect was observed in pancreatic carcinoma cells treated with farnesyltransferase inhibitor R115777. Microarray assay on the global gene expression profile demonstrated that a total of 132 genes were significantly modulated by atorvastatin; and Waf1p21, cyp51A1, and soluble epoxide hydrolase were crucial atorvastatin‐targeted genes which involve in inflammation and carcinogenesis. This study indicates that atorvastatin has the potential to serve as a chemopreventive agent against pancreatic carcinogenesis.

An Uncommon Cause of Peripancreatic Fluid

Gastroen Question: A 68-yearold man was admitted for management of complications secondary to necrotizing pancreatitis. One month before admission, he underwent laparoscopic cholecystectomy for clinically severe gallstone pancreatitis. He was readmitted with symptoms of gastric outlet obstruction in the face of 23-pound weight gain, significant abdominal distention, and pitting edema of the abdominal wall and bilateral lower extremities to the level of the thighs. Laboratory studies were notable for: white blood cell count, 21.5 10 (normal, 3.5–10.5 10); aspartate aminotransferase, 188 U/L (normal, <8–43), alanine aminotransferase, 137 U/L (normal, 7–45), alkaline phosphatase, 1263 U/L (normal, 55–142), total bilirubin, 1.8 mg/dL (normal, 0.1–1.0), direct bilirubin, 1.4 mg/dL (normal, <0.3); International Normalized Ratio, 1.7; and albumin 2.3 g/dL (normal, 3.5–5.0). Computed tomography of the abdomen and pelvis demonstrated a large area of walled-off pancreatic necrosis with moderate abdominal and pelvic ascites (Figure A). Endoscopic intervention was undertaken. Endoscopic ultrasonographyguided cystgastrostomy with 3 direct endoscopic necrosectomies were performed over the next 2 months. Symptomatic ascites persisted requiring 2 large-volume paracenteses. Ascitic amylase and triglyceride levels were normal. One month later (3 months after the initial onset of pancreatitis), endoscopic retrograde cholangiopancreatography (ERCP) demonstrated a large pancreatic duct leak. Transpapillary stent placement was performed with clinical improvement and decrease in ascites. At follow-up ERCP 1 month later for stent removal, fluid was emerging from the papilla (Figure B). What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.

Chemoprevention of Chronic Inflammatory Bowel Disease-Induced Carcinogenesis in Rodent Models by Berries

Long-term chronic inflammation including inflammatory bowel disease is a well-recognized risk factor for cancer development. Fresh fruits, particularly berries, have been well documented as having protective effects against inflammation and cancer development. There are several key elements in the berries with functions against cancer, including vitamins (A, C, E, and folic acid), minerals (calcium and selenium), phenol compounds (particularly ellagic acid, ferulic acid, chlorogenic acid, coumaric acid, quercetin and anthocyanins), phytosterols (β-sitosterol, campesterol, and stigmasterol) and oligosaccharides. This chapter focuses on linking berries to chronic colitis-induced carcinogenesis from experimental evidence to potential usefulness on cancer prevention and treatment.

Altered Bowel Habits and Occult Gastrointestinal Bleeding in a 67-Year-Old Man

Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 Question: A 67-year-old man with a history of chronic lymphocytic leukemia (CLL) complicated by recurrent bacterial infections presented to the outpatient clinic with an abrupt onset of altered bowel habits. He reported the urge to defecate several times per day, but only had occasional passage of small, semisolid stools. At baseline, he typically experienced having 1 to 2 large bowel movements per day. Screening colonoscopy was performed 3 years prior and was notable for a 4-mm tubular adenoma in the ascending colon, with an adequate bowel preparation noted. Physical examination was significant for cervical lymphadenopathy, and a normal digital rectal examination, without a palpable mass or impaction. Basic laboratory testing was significant for a hemoglobin of 11.5 g/dL (normal, 13.5-17.5) and leukocyte count of 87,500 cells/mL (normal, 3500-10,500), with a lymphocytic predominance. Peripheral smear showed no blast cells. Colonoscopy revealed a large hemorrhagic mass in the terminal ileum with partial obstruction of the bowel lumen (Figure A low power image). Biopsies were obtained, and histology revealed a dense lymphocytic infiltrate in the bowel mucosa (Figure B, high power image). Treatment with rituximab was initiated, the patient’s anemia improved, and his bowel habits returned to normal. What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. 102 103 104 105 106 107 108 Conflicts of interest The authors disclose no conflicts.

Mo1331 When, Why and How Do Patients With Acute Pancreatitis Die? A Large Experience of 910 Direct (Not Transfer), Consecutive Admissions in Recent Years

G A A b st ra ct s Pancreatitis after Minor Papilla Endoscopic Sphincterotomy ( FRAMES )study. Results: RAP patients had at least 2 or more episodes of pancreatitis and were aged 45.82; m/f 18/31. There were 31 subjects in the FRAMES study. Mean age:56.8 y, 52% were males. From the QLQ-C30 and QLQ-PAN26 the professionals identified 22 issues relevant to RAP, including pain, fatigue, eating/food/GI symptoms, bowel function, social and family function, and financial worries. RAP patients reported significant impairment (similar to CP) in quality of life in Role/Emotional/Cognitive/Social and Sexual domains and increased symptoms: Pain/ altered bowel/N+V, Fatigue/insomnia. Overall QOL was reduced less than in CP patients (mean scores as %: normal 71; RAP 57; CP 39). Conclusions: RAP significantly impairs quality of life compared to normal individuals. Impairment in most domains is similar to CP. A subset of questions form the EORTC QLQ-C30 and QLQ-PAN26 can be used as a new RAP QOLI for future studies of RAP Functional scales in Normal, Recurrent Acute Pancreatitis, Chronic Pancreatitis and Patients with Pancreas divisum undergoing minor papillotomy

Inhibition of Pancreatitis and Carcinogenesis by Capsaicin

Pancreatic cancer is one of the most lethal malignant neoplasms. The risk and prevention factors are strongly related to life and dietary style, environment, genetic factors, and genetic-environment interaction. Chronic pancreatitis is one of well-recognized risk factors for pancreatic cancer development. Fresh vegetables and fruits have been well documented having protective effect against inflammation and cancer development. Chili pepper is the fruit of plants from the genus Capsicum, and capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a colorless irritant phenolic amide, found in various capsicums that give the spicy taste. Epidemiologic and animal studies indicate that capsaicin is a highly potential agent in prophylaxis and treatment of diabetes, analgesic, inflammatory disease and cancer. This chapter focuses on linking capsaicin to pancreatitis and pancreatic carcinogenesis from experimental evidence to potential usefulness on prevention and treatment of this highly lethal malignant disease – pancreatic cancer.