W1726 ERK MAP Kinase Signalling and PEA3 are Synergistic in Predicting Adversity in Gastric Adenocarcinomas

W1726 ERK MAP Kinase Signalling and PEA3 are Synergistic in Predicting Adversity in Gastric Adenocarcinomas

hours, the mice were sacrificed and the stomachs removed. Mucosal lesion area was measured by planimetry using an Image J program. Gastric corpus frag...

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hours, the mice were sacrificed and the stomachs removed. Mucosal lesion area was measured by planimetry using an Image J program. Gastric corpus fragments were removed and stored until assayed for MPO, MDA, GSH and cytokines (TNF-α, IL-1β, IL-10). Results: Hemin, biliverdin or DMDC reduced (p<0.05) the gastric lesion (Hemin=13.3±1.3; biliverdin= 21.5±2.4; DMDC=6.1±1.4 mm2), the MPO activity (Hemin=8.2±1.2; biliverdin=16.4±4.0; DMDC=8.2±0.9 U/mg), the MDA levels (Hemin=87.6±6.0; biliverdin=58.8±4.3; DMDC= 88.1±11.9 nmol/g), TNF-α (Hemin=1099.0±121.0; biliverdin=979.9±114.0; DMDC= 1035.0±77.3 pg/ml) and IL-1β (Hemin=2675.0±179.0; biliverdin=2456.4±124.0; DMDC= 3046.0±429.0 pg/ml), and increased the GSH concentration (Hemin=112.2±11.1; biliverdin= 275.5±47.5; DMDC= 186.7±32.2 μg/g), and IL-10 concentration (Hemin=1482.0±200.0; biliverdin=1558.8±144.0; DMDC=1490.0±114.0 pg/ml) in gastric mucosa, compared with the indomethacin alone (gastric lesion=30.7±5.9 mm2, MPO= 24.9±3.3 U/mg, MDA= 128.9±6.2 nmol/g, GSH=58.7±4.7 μg/g, TNF-α=1527.0±159.0, IL-1β=4007.0±275.0 and IL-10=970.7±32.6 pg/ml). ODQ (gastric lesion=16.0±2.2 mm2, MPO=29.7±1.8 U/mg, MDA=128.9±9.4 nmol/g, GSH=64.6±19.2 μg/g) and L-NAME (gastric lesion=17.0±3.4 mm2, MPO= 27.2±2.4 U/mg, MDA=133.5±8.4 nmol/g, GSH=78.3±5.2 μg/g) reversed the DMDC, but not biliverdin, induced gastric protection against indomethacin- induced gastropathy. Conclusion: Our results suggest that HO-1/ biliverdin/CO pathway plays a protective role against indomethacin-induced gastric damage through mechanisms that can be dependent (CO) or independent (biliverdin) of soluble guanylate cyclase and the constitutive NO synthase activations. Financial support: CNPq- Brazil.

to avoid ROS-mediated cell death in cancerous cells, thus allowing successful viability of cancerous tissue.

Diagnosis of Scirrhous Carcinoma of the Proximal Stomach Aided by a Novel Functional Lumen Imaging Probe Johannes Lenglinger, Margit Eisler, Sheida Mehrain, Marita Koelz, Martin Riegler, Johannes Zacherl, Gerhard Prager Background: A novel functional lumen imaging probe (EndoFLIP®) uses impedance planimetry to assess distensibility of the esophagogastric junction (EGJ). We report a case where this device helped to establish a diagnosis of a scirrhous carcinoma of the proximal stomach. A male patient, age 84 yrs., with a 6 months history of dysphagia, regurgitation and weight loss was referred with suspected achalasia. No stricture, esophagitis or tumor had been detected by endoscopy and a computed tomography of thorax and abdomen. Proton pump inhibitors had failed to relieve symptoms. Manometry showed normal resting pressure of the lower esophageal sphincter and impaired relaxation upon swallowing (residual pressure 15 mmHg). Achalasia was ruled out by preserved peristalsis of the esophageal body. Methods: For the assessment of EGJ distensibility a bag is mounted on a catheter and connected to a motor controlled syringe filled with a fluid of defined conductivity. Impedance measurements between pairs of electrodes inside the bag are taken to measure the cross sectional areas (CSA) at 5 mm distances over a length of 80 mm. Intrabag pressure is monitored by a solid state pressure transducer. Volume, estimated diameters and intrabag pressure are displayed on a screen in real time. The bag was inserted transnasally and centered on the EGJ. 3 series of stepwise distensions up to a volume of 30 ml were performed. Results: With 30 ml a mean smallest CSA of 25 mm2 corresponding to an intrabag pressure of 54 mm Hg was recorded. Distensibility of the EGJ appeared severely compromised compared to healthy volunteers (0.46 mm2/mmHg vs. 8 ± 2 mm2/mmHg).1 Diameters <10 mm were present over a length of 3 cm. An intramural neoplasia at the EGJ was suspected. A computed tomography with fluid distension of the stomach showed thickening and enhanced contrast media uptake of the proximal gastric and distal esophageal wall and possible infiltration of the right diaphragmatic crus. Subsequent laparoscopy with multiple biopsies established a diagnosis of scirrhous carcinoma of the stomach (G3 T4N1M1). A stent was deployed at the EGJ and palliative chemotherapy initiated. Conclusion: EndoFLIP® measurements were decisive for identifying scirrhous carcinoma of the stomach as cause of dysphagia in this patient. Grossly impaired distensibility of the EGJ should raise the suspicion of an underlying malignancy not detectable by endoscopy. Ref: 1. Kwiatek M, Hirano I et al Increased esophagogastric junction distensibility in GERD patients assessed with the endoscopically placed functional luminal imaging probe (EndoFLIP®) Gastroenterology 2009;136:A-16

W1723 Long-Term Follow-up of Patients With Gastric Gastrointestinal Stromal Tumors (GISTs) 5 CM or Less After Surgical or Endoscopic Resection Mi-Young Kim, Kee Don Choi, Jeong Hoon Lee, Hye-won Park, Do Hoon Kim, Kwi-Sook Choi, Ho June Song, Gin Hyug Lee, Hwoon-Yong Jung, Jin-Ho Kim Objective: The recurrent potential of small gastric gastrointestinal stromal tumors (GISTs) remains unknown. In addition, the role of laparoscopic or endoscopic resection and the significance of positive microscopic resection margin are not well defined. The aim of the study was to evaluate the prognostic factors through the long-term outcome of small gastric GISTs by the range in size, mitotic index, and the method of resection with microscopic resection margin. Methods: Between March 1997 and December 2008, a total of 248 patients had surgical or endoscopic resection for gastric GISTs at Asan Medical Center. Among them, 145 patients with primary gastric GISTs 5 cm or less without metastasis underwent surgical or endoscopic resection and were followed up at least 3 months after resection. We confirmed pathologic diagnosis through the resected specimen with immunohistochemistry (c-kit, CD34), and checked the size, mitotic index, and microscopic resection margin. We reviewed initial and follow-up upper endoscopy and CT images for local recurrence or distant metastasis, retrospectively. Results: Among 145 patients, male was 65 and mean age was 58 years (range, 30~80). 141 had surgical resection and 4 had endoscopic resection. 87 were performed laparoscopic excision or wedge resection. Mean size of the tumors was 3.2 cm (range, 0.3~5 cm). They were stratified to 16 high risks, 23 intermediate risks, 83 low risks, 24 very low risks, and 1 indeterminate risk by NIH classification, respectively. 14 (9.7%) showed positive microscopic resection margin. During a mean follow-up of 35 months (range, 3~106) after resection, 4 (2.8%) showed recurrence at mean follow-up of 29 months (range, 16~50). They were all high risk GISTs with mean size of 4.2 cm (range, 3.2~5.0). All of them presented with distant metastasis to liver or peritoneum. Among 14 with positive microscopic resection margin, 2 were high risks and 2 were intermediate risks. All of the patients with microscopic resection margin did not show recurrence during mean followup of 37 months (range 5~83). Mitotic index was a predictor of recurrence (p < .001), but tumor size more than 3 cm (p= .297), laparoscopic resection (p= .298), and positive microscopic resection margin (p= .347) did not show different outcome. Conclusions: 2.8% of small gastric GISTs 5 cm or less showed distant metastasis after resection. Only mitotic index was the prognostic predictor of small gastric GISTs.

W1726 ERK MAP Kinase Signalling and PEA3 are Synergistic in Predicting Adversity in Gastric Adenocarcinomas Richard Keld, Baoqiang Guo, Paul Downey, Christian Gulmann, Yeng S. Ang, Andy Sharrocks Introduction: The PEA3 sub family consists of 3 similar transcription factors, PEA3, ER81 and ERM. In gastric cancer cells PEA3 is activated by H pylori and it has been shown to regulate MMP-7 and invasion. PEA3 mRNA expression correlates with an adverse prognosis in gastric adenocarcinomas. We have previously shown that PEA3 and/or ER81 mRNA correlates with adverse the indicator, MMP-1 and MMP-7. Very high PEA3 protein expression in isolation is associated with tumour metastases., however However tumours with PEA3 mRNA and lower protein expression did not correlate with prognostic markers. PEA3 is regulated by ERK MAP kinase signalling in oesophageal adenocarcinomas and we investigated if this pathway plays an important role in gastric adenocarcinomas. Methods: Patients with gastric adenocarcinoma (37) and controls (11) were selected. Tissue microarrays were constructed for immunohistochemical studies of PEA3 and pERK. The t test and chi square test were used for statistical analysis. A P value < 0.05 was judged to be significant. Results: In patients with gastric adenocarcinoma, active ERK signalling is present in 60%. From these, ERK signalling is associated with an advanced tumour stage (AJCC stage 1 67 %, stage 2: 33%, stage 3: 21% stage 4: 80% p=0.04). Active signalling is present in stage 1and 2 tumours (55%). Survival is significantly reduced in patients with active ERK signalling (41 vs 34 months P=0.05) on univariate analysis. Adenocaricinomas with PEA3 and pERK co-occurrence frequently have distant metastases 60% (T and N stage vs M stage P=0.048). Survival is worse in patients with combined pERK presence and PEA3 expression compared to PEA3 or pERK expression in isolation (12 vs 30 vs 63 months P=0.071). Conclusion: Our results indicate that ERK MAP kinase signalling is an important marker of an advanced tumour stage and prognosis in gastric adenocarcinoma. The signalling pathway is frequently active in early stage (AJCC 1-3) tumours . Previous studies have shown poor results with MEK inhibition treatment in Pancreatic, Colon, Lung and Breast cancers. This may be due to the selection of heterogenous tumours with an advanced disease stage or tumours with activation of alternative signalling pathways. Our results suggest consideration of trialling MEK inhibition treatment in patients with earlier stage disease in Gastric adenocarcinoma. The more adverse outcome in patients with the combination of ERK MAP signalling and PEA3 indicates that a combined approach with inhibition of PEA3, could be considered in selected patients.

W1724 Relationship Among Oxidative Changes and the Proliferation Rate in Healthy, Tumor-Free, and Adenocarcinoma-Derived Human Gastric Mucosa Eduardo E. Montalvo-Jave, Rolando Hernandez-Muñoz Gastric cancer in a significant public health problem worldwide, constituting one of the first five causes of global mortality. Here, it has been suggested that Reactive oxygen species (ROS) could be involved in the inflammatory component that constitutes a major feature in gastric carcinogenesis, such as in gastric adenocarcinona. Hence, the present work aimed to assess the role of ROS, their putative deleterious effects on the cell redox state, and its possible implication on uncontrolled proliferation of cells from gastric mucosa. For this, we obtained samples from gastric mucosa taken from healthy subjects (n = 10), removed as a part of surgical treatment for morbid obesity, and from the gastric mucosa of 15 patients diagnosed with gastric adenocarcinoma at several stages of malignancy. In the latter, another 15 samples were obtained from gastric mucosal tissue distant from the tumor area and were considered as healthy or tumor-free gastric mucosa. Gastric mucosa was scraped and subjected to subcellular (plasma membrane, cytosol, mitochondria, and microsomes) fractionation. In addition, a protein-free acid extract was also obtained. Parameters indicative of lipid peroxidation, cell redox state, and cell proliferation indicated that lipid peroxidation was drastically increased in diseased gastric mucosa in both tumor-free and in cancerous gastric mucosa when compared with control tissue, with lipid peroxidation significantly lower in tumor cells. The cytoplasmic redox potential (NAD/NADH ratio) was decreased in gastric mucosa from the tumor-free area, but in adenocarcinoma, this ratio was even lower, suggesting a reduced redox state, characterizing tumor tissue. Cancerous cells exhibited a drastic increase in DNA synthesis when compared with the tumor-free area; however, DNA synthesis was indeed much higher in cells from the tumor-free area than that found in control samples. In conclusion, chronically injured gastric mucosa readily increases lipoperoxidative events and cell proliferation, showing a more reduced metabolic condition. However, as soon as the gastric mucosa is transformed into a malignant state, the rate of cell proliferation is further enhanced, but is now accompanied by decreased oxidant stress, probably as a strategy

W1727 Prognostic and Survival Factors in Esophageal Cancer Alejandro Cruz-Zarate, Sergio R. Sobrino-Cossio, Angelica Hernandez-Guerrero, Juan Octavio Alonso-Larraga, Beatriz F. Barranco INTRODUCTION Esophageal cancer is classified in two subtypes: squamous cell and adenocarcinoma. Approximately 400, 000 new cases are diagnosed annually worldwide, it is 8th in frequency and due to its aggressive behavior has poor survival (20%). It is the 6th cause

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