- Email: [email protected]
Reperfusion Injury
c-insertion mutation (3020InsC cell line). Western blot and PCR was used to identify NOD2. Cells were then grown in 6 well plates for 72 hours until confluent. The monolayer was then wounded with a plastic pipette tip in an X formation. 24 or 48 hours later the cells were stained Hema 3 stain kit and viewed with a phase contrast microscope. Duplicate, unwounded, monolayers were used to measure cell proliferation using a coulter counter, n=8. Results: Human NOD2 protein was detected by Western blot and PCR in the NOD2 and 3020InsC cell lines, but not the parental cell line. There was a significant increase in proliferation in the NOD2 cell line compared to the parental cell line (p<0.05). There was no significant change in proliferation in the 3020InsC cell line compared to parental and NOD2 cell lines. The figure shows monolayer wound healing for the three cell lines at 24 hours. The wounds in the NOD2 cell line healed the quickest. They were nearly closed at 24 hours and undectable at 48 hours. The parental cell line had intermediate healing. There was minimal to no wound healing in the 3020InsC cell line at 24 hours or 48 hours. In addition, the 3020InsC cells seemed to bunch up in a “ridge” at the edge of the wound suggesting migration into the wound was impaired. This “ridge” was not seen in the NOD2 or parental cell lines. Conclusions: 1. Wound healing was markedly retarded in the 3020InsC cell line compared to the parental cell line while the NOD2 cell line healed more quickly than the parental cell line. 2. The increase in proliferation seen in the NOD2 cell line may contribute to the improved wound healing in this cell line. However, there was no change in proliferation in the 3020InsC cell line to explain the lack of wound healing in the 3020InsC cell line. 3. The disruption in the tight junction complex we have previously described in the 3020InsC cell line may contribute to the delay in wound healing. 4. Lack of wound healing may have implications in the mucosal injury and repair seen in CD. Su1841 A Sprayable Hyaluronate/Carboxymethylcellulose Based Adhesion Barrier Reduces Remote Intraabdominal Adhesion Formation and Does Not Impair Intestinal Healing Holly K. Sheldon, Melanie L. Gainsbury, Michael R. Cassidy, M. Jude Colt, Rubina L. Corazzini, Olga L. Syrkina, Keith E. Greenawalt, Thomas H. Jozefiak, Arthur F. Stucchi, James M. Becker
Left: IEC-18 parental, Middle: NOD2 Wildtype, Right: 3020InsC mutant
Background: Intraabdominal adhesions are a significant source of postoperative morbidity. While bioresorbable solid physical barriers such as modified hyaluronate/carboxymethylcellulose (HA/CMC) film (Seprafilm - SF) are effective in preventing adhesions, their efficacy is limited to the site of application. The aim of this study was to compare the effectiveness of modified HA/CMC sprayable powder (Sepraspray - SS) and SF in preventing adhesions not only to sites of direct application, but also to remote peritoneal defects to which a barrier was not directly applied. Methods: Adhesion reduction was assessed in a rat ischemic button model and also in a rabbit cecal-sidewall injury model. Intraabdominal adhesions were induced in 30 rats by creating 3 peritoneal sidewall ischemic buttons on each side of a midline incision. SS (5 mg/button) or SF (1 cm2/button) was applied intraoperatively over the 3 ischemic buttons on one side of the midline only. Adhesions were induced in 50 rabbits by cecal abrasion with the concurrent creation of a 3 cm x 5 cm sidewall defect delineated with silk sutures and knots. Operated control animals received no SS or SF. On day 7 adhesions were scored in rats as the percent of buttons with attached adhesions and in rabbits as the % of the sidewall defect covered by adhesions. To assess the effect of either SS or SF on intestinal healing, an additional 27 rats underwent a colonic transection distal to the cecum, which was repaired with an end-to-end anastomosis. SS or SF was applied circumferentially to the anastomosis site. The anastomosed colonic sections were removed 7 days later and their integrity assessed by burst pressure and tensile strength measurements. Results: The direct application of both SS and SF significantly (p<0.04) reduced adhesion formation compared with controls in both efficacy models (Table). While SF had no remote effects on adhesion formation in either model, SS significantly (p<0.01) reduced adhesion formation to ischemic buttons to which the powder was not directly applied. In rabbits, SS reduced remote adhesion formation to the sidewall defect by 70% (p<0.1). In the anastomosis healing model, neither SF nor SS affected intestinal anastomotic burst pressure (Control: 240 ± 8.2 vs. SS 215 ± 19.0 vs. SF: 216 ± 27.2 mm Hg) or tensile strength (Control: 2.4 ± 0.2 vs. SS: 2.3 ± 0.2 vs. SF: 2.2 ± 0.2 Newton). Conclusions: While both SS and SF have comparable adhesion reduction efficacy where applied, SS was additionally effective in reducing adhesion formation at remote sites of peritoneal injury to which SS was not applied directly. These data suggest that SS may have widespread efficacy throughout the peritoneum in reducing adhesion formation without compromising intestinal wound healing.
Su1842
Background: Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis associated with locally advanced esophageal cancer. However, only patients with a major histopathologic response to neoadjuvant therapy seem to have a significant survival benefit. We have shown in a recent pilot study using microarray-technique that the expression profile of microRNAs depends significantly on the histopathologic response of patients with locally advanced esophageal cancer undergoing multimodality treatment. This study aimed to validate these identified single microRNAs by real-time PCR. Patients and Methods: Eighty-eight patients with locally advanced esophageal cancer (cT2-4, Nx, M0) were included in the study. All patients received neoadjuvant chemoradiation (cisplatin, 5-FU, 45 Gy) and subsequently underwent transthoracic en bloc esophagectomy. Histomorphologic regression was defined as major histopathological response when resected specimens contained less than 10% vital residual tumor cells (major response: 34 patients; minor response: 54 patients). Intratumoral microRNA was isolated from pretherapeutic tissue biopsies and corresponding surgical specimens. Based on the microarray results, the amplification profile of dysregulated microRNAs was analyzed and the microRNAs 192, 194 and 622 were selected for the further analysis of the validation population. Results: The expression of all three microRNAs was significantly reduced during neoadjuvant therapy, showing lower levels in post-therapeutic tumor samples (p<0.001). Furthermore, the pre-therapeutic intratumoral expression of microRNA 192 was significantly correlated with histopathologic response: patients with a major response had a significantly higher intratumoral microRNA 192 amount compared with patients having a minor response (p=0.01). Moreover, by using an expression cut-off value of 0.63, the sensitivity, specificity and accuracy of pre-therapeutic microRNA 192 for assessment of histopathologic response was 96%, 82% and 88% respectively (p= 0.05). Conclusion: Our data support the role of micro RNA 192 as a predictive marker for therapy response in the multimodality therapy of patients with locally advanced esophageal cancer. In a multi-institutional trial we will now try to confirm these results. Su1843 Diazoxide, a Opening mitoKATP, Reduces Liver Damage Secondary to Ischemic/Reperfusion Injury Mateus A. Nogueira, Ana Maria M. Coelho, Sandra N. Sampietre, Nilza A. Molan, Luiz Augusto C. D'Albuquerque, Marcel C. Machado Background/Aim: Previous studies have demonstrated that diazoxide protects heart from ischemia/reperfusion injury however there are no prior studies of the role of diazoxide on liver ischemic reperfusion injury. In the present study we evaluated the effect of diazoxide on local and systemic liver ischemia/reperfusion (I/R) process. Methods: Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from medium and left anterior lateral segments during an hour under mechanical ventilation. They were divided into 2 groups: Control Group (n=26): rats received saline and Diazoxide Group (n=26): rats received IV diazoxide (3.5mg/kg) 15 minutes before liver reperfusion. Four and 24 hours after reperfusion, blood were collected for determinations of AST, ALT, TNF-α, IL-6, and IL-10. Liver tissues were assembled for histologic analysis, malondialdehyde (MDA) content, and mitochondrial oxidation and phosphorylation. Pulmonary vascular permeability and myeloperoxidade (MPO) were also determined. Results: Four hours after reperfusion Diazoxide Group presented elevation of AST, ALT, TNF-α, IL-6 and IL-10 serum levels
Su1841a NOD2 Mutation Results in Altered Wound Healing in Epithelial Cells Lisa S. Poritz, Leonard R. Harris Introduction: A mutation in the NOD2 gene has been linked to terminal ileal Crohn's Disease (CD). CD is characterized by repeated mucosal injury and healing. No work has been done on the effect of the NOD2 mutation on wound healing. We have stably transfected the IEC18 cell line (ileal cells) with wildtype and the c-insertion mutation of the NOD2 gene. We have previously characterized these cells and have found marked disruption of the tight junction proteins in the cells carrying the NOD2 mutation. The hypothesis for this study is that there will be altered wound healing in the cells with the NOD2 mutation. Methods: IEC-18 cells were stably transfected with wild-type human NOD2 (NOD2 cell line) or the
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SSAT Abstracts
SSAT Abstracts
The Micro-RNA 192 as an Effective Response Prediction Factor in the Multimodality Therapy of Locally Advanced Esophageal Cancer Daniel Vallbohmer, Peter P. Grimminger, Christoph Wandhoefer, Jan Brabender, Uta Drebber, Elfriede Bollschweiler, Arnulf H. Hölscher, Ralf Metzger, Magarethe Odenthal
significantly lower than Control Group (p<0.05). A significant reduction on liver MDA content and on mitochondrial dysfunction were observed in Diazoxide Group compared to Control Group (p<0.05). No differences in pulmonary vascular permeability and MPO activity were observed between groups. Twenty four hours after reperfusion Diazoxide Group showed a reduction of AST and ALT serum levels when compared to Control group (p<0.05). Conclusion: Diazoxide attenuates liver ischemia/reperfusion injury probably by a mechanism related to mitochondrial function preservation during liver ischemia.
Su1846 A Promising Novel Target in Pancreatic Cancer: HuR Modulates Multiple Core Signaling Pathways Required for Pancreatic Tumorigenesis Vanessa A. Talbott, Koree Ahn, David W. Rittenhouse, Nathan G. Richards, Agnes Witkiewicz, Eugene P. Kennedy, Myriam Gorospe, Charles J. Yeo, Jonathan R. Brody Introduction: Twelve core signaling pathways with 540 overexpressed individual genes have recently been identified as critical for the development of pancreatic ductal adenocarcinoma (PDA) (Science 2008, 321:1801-1806). The mechanism of overexpression for nearly all (99%) of the identified up-regulated genes in pancreatic tumorigenesis is unknown. We explored the hypothesis that post-transcriptional gene regulation may be a powerful alternative process in which these up-regulated genes were being disrupted. A key component of this regulatory process is Human antigen R (HuR), which can modulate gene expression by binding to mRNAs that encode for tumor-promoting proteins in cancer cells. Previously, we discovered that HuR is a key marker for poor pathologic features in PDA and is a predictive marker for gemcitabine-based chemotherapy. Methods: Using a bioinformatic approach, we identified putative HuR targets from the 540 overexpressed genes in PDA (Nucl. Acids Res. 2001, 29:246-254, PNAS 2004, 101:2987-92). HuR binding to mRNAtargets was validated by PCR-based analysis in ribonucleoprotein immunoprecipitated HuR:RNA complexes. Further validation of expression of HuR target genes was performed by quantitative PCR analysis and immunoblotting. Results: We identified 60 putative targets (11.1%) for HuR regulation among the overexpressed genes in PDA. In comparison, genetic and epigenetic alterations contribute only 1% and 1.8% respectively to the proposed mechanisms by which these 540 genes are disrupted in PDA. Ten of the 60 putative target genes which are a part of 5 of the 12 core signaling pathways in PDA, including K-Ras, were experimentally validated as specific HuR targets. Conclusion: HuR is an unprecedented regulatory protein of at least 5 critical signaling pathways in PDA. Targeting multiple core pathways in PDA through silencing HuR expression may be a potent therapeutic strategy to treat this disease.
Su1844 Pterostilbene Induces Mitochondrially-Derived Apoptosis in Pancreatic Cancer Cells by Increasing MnSOD Activity and Release of Cytochrome C and Smac/ DIABLO Denise E. McCormack, Debbie E. McDonald, David W. McFadden BACKGROUND: We have previously shown that Pterostilbene (3, 5- dimethoxy-4-hydroxystilbene), a compound found in blueberries, inhibits cell proliferation and promotes apoptosis in pancreatic cancer In Vitro by induction of mitochondrial membrane depolarization and caspase 3/7 activation. To further investigate the role of mitochondria in Pterostilbene-induced apoptosis in pancreatic cancer, we examined its effects on manganese superoxide dismutase (MnSOD) activity, Cytochrome C and Smac/DIABLO release. The mitochondrial enzyme MnSOD plays a critical role in regulation of cancer cell proliferation through an unknown mechanism. Smac/DIABLO is a mitochondrial protein that potentiates apoptosis. Both Smac/DIABLO and Cytochrome C have been shown to exit mitochondria and enter the cytosol during apoptosis. We hypothesized that Pterostilbene would increase MnSOD activity and cytosolic levels of Cytochrome C and Smac/DIABLO in a dose dependent manner. METHODS: MIA and PANC-1 cell lines were treated with 25 micromolar and 50 micromolar concentrations of Pterostilbene for 48hrs and quantitative MnSOD activity was measured by superoxide dismutase ELISA assay. In separate experiments, MIA and PANC-1 cell cells were treated with 25 micromolar, 50 micromolar and 75 micromolar concentrations of Pterostilbene for 24hrs and cytosolic extracts were analyzed for Cytochrome C and Smac/ DIABLO utilizing ELISA protocols. One way ANOVA and Tukey post-hoc analysis were used for statistical analysis. RESULTS: Pterostilbene increased enzymatic activity of MnSOD in both cell lines in a dose dependent manner (p <0.01). Pterostilbene treatment increased cystosolic levels of Cytochrome C in MIA cells at the 25 micromolar (p < 0.05) and 75 micromolar concentrations in PANC-1 cells (p < 0.05). Cystosolic levels of Smac/DIABLO increased in both MIA and PANC-1 cells with treatment at the 75 micromolar concentration of Pterostilbene (p <0.01). CONCLUSION: We have previously demonstrated that Pterostilbene, a natural plant-derived stilbene, inhibits pancreatic cancer In Vitro through activation of the mitochondrial apoptosis pathway. MnSOD, an inducible mitochondrial enzyme that converts superoxide anion to hydrogen peroxide, has an essential role in regulation of pancreatic cancer cell proliferation. The results of our current study demonstrate for the first time that Pterostilbene increases MnSOD activity in pancreatic cancer cells. In addition, Pterostilbene increases cytosolic levels of Cytochrome C and Smac/DIABLO in both cell lines, confirming mitochondrially derived apoptotic cell death. Further studies are ongoing to elucidate the intricate relationship between intrinsic apoptosis, MnSOD activity, and pancreatic cancer cell death upon Pterostilbene treatment.
Su1847 Changes in Neurotransmission via Alpha- and Beta-Receptors During Postoperative Ileus in Rat Circular Jejunal Muscle Michael S. Kasparek, Brigitte Goetz, Bernhard Stoklas, Petra Benhaqi, Mario H. Mueller, Martin E. Kreis Background Our aim was to: 1) investigate the role of α and β-receptors in control of contractile activity in rat circular jejunal muscle; 2) explore changes in adrenergic neurotransmission via these receptors during postoperative ileus (POI); 3) determine if these changes are paralleled by intramural inflammation and delayed intestinal transit. Methods Muscle strips (n=8/rat) from 6 male Sprague Dawley rats per group were studied in organ chambers. Groups: Naïve controls (NC), sham controls (SC) 24h after laparotomy, rats 12h (P12h), 1 (P1d), 3 (P3d), and 7days (P7d) after laparotomy and standardized small bowel manipulation to induce POI. After spontaneous contractile activity (g/mm2/min) was recorded, dose-response curves for phenylephrine (αa; α-agonist; 10-8-3x10-6M) and isoprenaline (βa; β-agonist; 3x10-10-10-7M) were established. Responses were repeated with tetrodotoxin (TTX; blocking enteric nerves; 10-6M), after precontraction with bethanechol (3x10-6M), and with phentolamine (α-anatagonist; 10-5M), or propranolol (β-antagonist; 5x10-6M). Intestinal transit was studied by charcoal transit (% of small bowel passed). Histology of jejunal whole mounts was performed for myeloperoxidase positive cells (MPO), macrophages, and mastcells (cells/mm2).Data: mean±SEM. Results Spontaneous contractile activity was increased in SC, P12h, and P7d (NC 1.3±0.3; SC 3.7±0.9; P12h 4.5±1.5; P7d 3.6±1.0; p<0.05), but not in P1d (1.7±0.4) and P3d (1.8±0.5; p=NS). αa and βa inhibited spontaneous contractile activity dose-dependently in all groups (p<0.05). In NC, TTX reduced αa-induced inhibition (p<0.05), but TTX had no effect on αa-responses in POI groups (p= NS). In contrast, TTX did not affect βa-response in NC (p=NS), but increased responses in POI groups (p<0.05). αa and βa-induced inhibition was reduced in P12h, P3d, and P7d and in all POI groups, respectively (p<0.05). Precontraction had no effect on αa and βaresponses (p=NS). Effects of αa and βa were blocked by phentolamine or propranolol (p<0.05). Intestinal transit was delayed in all POI animals and recovered over time (NC 53±3; P12h 22±2; P7d 44±2%; p<0.05), but was unaffected in SC (50±5%; p=NS). MPO positive cells and mastcells increased postoperatively and peaked in P1d (NC 14±2; P1d 763±48) and P12h (NC 9±1; P12h 700±79; both p<0.05), respectively; no effect was observed in SC (56±37 and 30±12, respectively; p=NS). Macrophages peaked in P3d (NC 367±41; P3d 1306±178; p<0.05); counts in SC and P12h were similar to NC (SC 395±82; P12h 706±19; p=NS). Conclusion Contractile activity can be inhibited predominantly via muscular α- and β-receptors. However, during POI long lasting changes in balance of muscular and neuronal α- and β-receptors occur that might participate in pathophysiology of POI. These changes are paralleled by intramural inflammation and impaired intestinal transit. DFG KA 2329/5-1
SSAT Abstracts
Su1845 Systemic Inflammation With Multiorgan Dysfunction is the Cause of Death in Murine Pancreatic Duct Ligation-Induced Acute Pancreatitis Zuobiao Yuan, David Meyerholz, Deborah Williard, Erik Twait, Kempuraj Duraisamy, Isaac Samuel Existing animal models of acute pancreatitis (e.g., cerulein, choline-deficient ethioninesupplemented diet) do not resemble gallstone pancreatitis as the etiologies are not analogous. Distal pancreatic duct ligation (PDL) more closely resembles early events in gallstone pancreatitis. We recently developed a novel murine model of PDL-induced acute pancreatitis associated with substantial mortality. Using this model, we previously showed that specific inhibition of the stress kinase ERK with In Vivo gene modulation significantly improves survival. In the present study we determine the cause of death in our murine model by serial examination of multiple parameters in three groups: a) Acute pancreatitis group had PDL; b) Hepatic obstruction group had bile duct ligation (BDL) without PDL; c) Sham operation group. The mice were observed for 15 days post-operatively. BDL and Sham controls had no mortality. Close to 100% mortality was seen in PDL-induced acute pancreatitis with most deaths occurring between day 2 and day 4. Characteristics of mice with acute pancreatitis included the following (ANOVA; P<0.05): ERK activation in the pancreas and distant organs; pancreatic neutrophil infiltration and acinar cell necrosis maximal on day 2; increased plasma IL-1β and TNF-α levels on day 2, that peaked on day 3, in parallel with worsening hypotension and bradycardia; bronchoalveolar lavage (BAL) fluid neutrophil count and IL1β level, and plasma aspartate aminotransferase (AST) level, also peaked on day 3; pulmonary neutrophil infiltration and plasma creatinine level peaked on day 4.. Liver injury evidenced by raised AST after hepatic obstruction was exacerbated by PDL. Increased plasma IL-1β and TNF-α on day 2 after BDL subsided thereafter. Although BDL was also associated with pulmonary neutrophil infiltration it was not associated with increased IL-1β or neutrophils in BAL fluid. BDL-induced renal tubular damage was not associated with raised plasma creatinine. Our findings indicate that the high mortality rate seen in PDL-induced acute pancreatitis in mice is associated with progressive systemic increase of inflammatory cytokine levels, cardiovascular instability, acute lung injury, liver injury, and renal dysfunction, suggesting that systemic inflammation with multiorgan failure is the proximate cause of death in this experimental model. Lung and renal injury as observed by morphology after hepatic obstruction alone is not associated with systemic inflammation or death. In conclusion, systemic inflammation with multiorgan dysfunction causes death in pancreatic duct ligation-induced acute pancreatitis in mice. This experimental model is a useful analogy of severe gallstone pancreatitis to investigate disease pathogenesis and to evaluate novel therapeutic strategies.
SSAT Abstracts
Su1848 Central Vagal Activation During Early Postoperative Ileus in the Mouse Mia Karpitschka, Mario H. Mueller, Michael S. Kasparek, Jorg Glatzle, Martin E. Kreis Introduction: Postoperative ileus (POI) involves reflex inhibition of intestinal motility and a subsequent intestinal inflammatory response that is characterized by efferent vagal modulation. However, the role of central vagal afferents in the early phase of POI is unknown. We, therefore, aimed to explore central vagal afferent nerve activation early during POI. Material and Methods: C57BL/6 mice were vagotomized 3-4 days prior to ileus experiments, while control animals received a sham operation without vagotomy. For ileus experiments, laparotomy was either followed by standardized small bowel manipulation to induce POI or sham treatment for control. Then, after 3h or 9h, the brain was removed, fixed and Fosimmunohistochemistry was performed to determine neuronal activation in the vagal nucleus of the solitary tract (NTS) and the area postrema. Each subgroup contained an n of 6. Data were analyzed by two-way ANOVA. Results: The number of Fos-positive neurons in the
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Left: IEC-18 parental, Middle: NOD2 Wildtype, Right: 3020InsC mutant
Background: Intraabdominal adhesions are a significant source of postoperative morbidity. While bioresorbable solid physical barriers such as modified hyaluronate/carboxymethylcellulose (HA/CMC) film (Seprafilm - SF) are effective in preventing adhesions, their efficacy is limited to the site of application. The aim of this study was to compare the effectiveness of modified HA/CMC sprayable powder (Sepraspray - SS) and SF in preventing adhesions not only to sites of direct application, but also to remote peritoneal defects to which a barrier was not directly applied. Methods: Adhesion reduction was assessed in a rat ischemic button model and also in a rabbit cecal-sidewall injury model. Intraabdominal adhesions were induced in 30 rats by creating 3 peritoneal sidewall ischemic buttons on each side of a midline incision. SS (5 mg/button) or SF (1 cm2/button) was applied intraoperatively over the 3 ischemic buttons on one side of the midline only. Adhesions were induced in 50 rabbits by cecal abrasion with the concurrent creation of a 3 cm x 5 cm sidewall defect delineated with silk sutures and knots. Operated control animals received no SS or SF. On day 7 adhesions were scored in rats as the percent of buttons with attached adhesions and in rabbits as the % of the sidewall defect covered by adhesions. To assess the effect of either SS or SF on intestinal healing, an additional 27 rats underwent a colonic transection distal to the cecum, which was repaired with an end-to-end anastomosis. SS or SF was applied circumferentially to the anastomosis site. The anastomosed colonic sections were removed 7 days later and their integrity assessed by burst pressure and tensile strength measurements. Results: The direct application of both SS and SF significantly (p<0.04) reduced adhesion formation compared with controls in both efficacy models (Table). While SF had no remote effects on adhesion formation in either model, SS significantly (p<0.01) reduced adhesion formation to ischemic buttons to which the powder was not directly applied. In rabbits, SS reduced remote adhesion formation to the sidewall defect by 70% (p<0.1). In the anastomosis healing model, neither SF nor SS affected intestinal anastomotic burst pressure (Control: 240 ± 8.2 vs. SS 215 ± 19.0 vs. SF: 216 ± 27.2 mm Hg) or tensile strength (Control: 2.4 ± 0.2 vs. SS: 2.3 ± 0.2 vs. SF: 2.2 ± 0.2 Newton). Conclusions: While both SS and SF have comparable adhesion reduction efficacy where applied, SS was additionally effective in reducing adhesion formation at remote sites of peritoneal injury to which SS was not applied directly. These data suggest that SS may have widespread efficacy throughout the peritoneum in reducing adhesion formation without compromising intestinal wound healing.
Su1842
Background: Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis associated with locally advanced esophageal cancer. However, only patients with a major histopathologic response to neoadjuvant therapy seem to have a significant survival benefit. We have shown in a recent pilot study using microarray-technique that the expression profile of microRNAs depends significantly on the histopathologic response of patients with locally advanced esophageal cancer undergoing multimodality treatment. This study aimed to validate these identified single microRNAs by real-time PCR. Patients and Methods: Eighty-eight patients with locally advanced esophageal cancer (cT2-4, Nx, M0) were included in the study. All patients received neoadjuvant chemoradiation (cisplatin, 5-FU, 45 Gy) and subsequently underwent transthoracic en bloc esophagectomy. Histomorphologic regression was defined as major histopathological response when resected specimens contained less than 10% vital residual tumor cells (major response: 34 patients; minor response: 54 patients). Intratumoral microRNA was isolated from pretherapeutic tissue biopsies and corresponding surgical specimens. Based on the microarray results, the amplification profile of dysregulated microRNAs was analyzed and the microRNAs 192, 194 and 622 were selected for the further analysis of the validation population. Results: The expression of all three microRNAs was significantly reduced during neoadjuvant therapy, showing lower levels in post-therapeutic tumor samples (p<0.001). Furthermore, the pre-therapeutic intratumoral expression of microRNA 192 was significantly correlated with histopathologic response: patients with a major response had a significantly higher intratumoral microRNA 192 amount compared with patients having a minor response (p=0.01). Moreover, by using an expression cut-off value of 0.63, the sensitivity, specificity and accuracy of pre-therapeutic microRNA 192 for assessment of histopathologic response was 96%, 82% and 88% respectively (p= 0.05). Conclusion: Our data support the role of micro RNA 192 as a predictive marker for therapy response in the multimodality therapy of patients with locally advanced esophageal cancer. In a multi-institutional trial we will now try to confirm these results. Su1843 Diazoxide, a Opening mitoKATP, Reduces Liver Damage Secondary to Ischemic/Reperfusion Injury Mateus A. Nogueira, Ana Maria M. Coelho, Sandra N. Sampietre, Nilza A. Molan, Luiz Augusto C. D'Albuquerque, Marcel C. Machado Background/Aim: Previous studies have demonstrated that diazoxide protects heart from ischemia/reperfusion injury however there are no prior studies of the role of diazoxide on liver ischemic reperfusion injury. In the present study we evaluated the effect of diazoxide on local and systemic liver ischemia/reperfusion (I/R) process. Methods: Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from medium and left anterior lateral segments during an hour under mechanical ventilation. They were divided into 2 groups: Control Group (n=26): rats received saline and Diazoxide Group (n=26): rats received IV diazoxide (3.5mg/kg) 15 minutes before liver reperfusion. Four and 24 hours after reperfusion, blood were collected for determinations of AST, ALT, TNF-α, IL-6, and IL-10. Liver tissues were assembled for histologic analysis, malondialdehyde (MDA) content, and mitochondrial oxidation and phosphorylation. Pulmonary vascular permeability and myeloperoxidade (MPO) were also determined. Results: Four hours after reperfusion Diazoxide Group presented elevation of AST, ALT, TNF-α, IL-6 and IL-10 serum levels
Su1841a NOD2 Mutation Results in Altered Wound Healing in Epithelial Cells Lisa S. Poritz, Leonard R. Harris Introduction: A mutation in the NOD2 gene has been linked to terminal ileal Crohn's Disease (CD). CD is characterized by repeated mucosal injury and healing. No work has been done on the effect of the NOD2 mutation on wound healing. We have stably transfected the IEC18 cell line (ileal cells) with wildtype and the c-insertion mutation of the NOD2 gene. We have previously characterized these cells and have found marked disruption of the tight junction proteins in the cells carrying the NOD2 mutation. The hypothesis for this study is that there will be altered wound healing in the cells with the NOD2 mutation. Methods: IEC-18 cells were stably transfected with wild-type human NOD2 (NOD2 cell line) or the
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SSAT Abstracts
SSAT Abstracts
The Micro-RNA 192 as an Effective Response Prediction Factor in the Multimodality Therapy of Locally Advanced Esophageal Cancer Daniel Vallbohmer, Peter P. Grimminger, Christoph Wandhoefer, Jan Brabender, Uta Drebber, Elfriede Bollschweiler, Arnulf H. Hölscher, Ralf Metzger, Magarethe Odenthal
significantly lower than Control Group (p<0.05). A significant reduction on liver MDA content and on mitochondrial dysfunction were observed in Diazoxide Group compared to Control Group (p<0.05). No differences in pulmonary vascular permeability and MPO activity were observed between groups. Twenty four hours after reperfusion Diazoxide Group showed a reduction of AST and ALT serum levels when compared to Control group (p<0.05). Conclusion: Diazoxide attenuates liver ischemia/reperfusion injury probably by a mechanism related to mitochondrial function preservation during liver ischemia.
Su1846 A Promising Novel Target in Pancreatic Cancer: HuR Modulates Multiple Core Signaling Pathways Required for Pancreatic Tumorigenesis Vanessa A. Talbott, Koree Ahn, David W. Rittenhouse, Nathan G. Richards, Agnes Witkiewicz, Eugene P. Kennedy, Myriam Gorospe, Charles J. Yeo, Jonathan R. Brody Introduction: Twelve core signaling pathways with 540 overexpressed individual genes have recently been identified as critical for the development of pancreatic ductal adenocarcinoma (PDA) (Science 2008, 321:1801-1806). The mechanism of overexpression for nearly all (99%) of the identified up-regulated genes in pancreatic tumorigenesis is unknown. We explored the hypothesis that post-transcriptional gene regulation may be a powerful alternative process in which these up-regulated genes were being disrupted. A key component of this regulatory process is Human antigen R (HuR), which can modulate gene expression by binding to mRNAs that encode for tumor-promoting proteins in cancer cells. Previously, we discovered that HuR is a key marker for poor pathologic features in PDA and is a predictive marker for gemcitabine-based chemotherapy. Methods: Using a bioinformatic approach, we identified putative HuR targets from the 540 overexpressed genes in PDA (Nucl. Acids Res. 2001, 29:246-254, PNAS 2004, 101:2987-92). HuR binding to mRNAtargets was validated by PCR-based analysis in ribonucleoprotein immunoprecipitated HuR:RNA complexes. Further validation of expression of HuR target genes was performed by quantitative PCR analysis and immunoblotting. Results: We identified 60 putative targets (11.1%) for HuR regulation among the overexpressed genes in PDA. In comparison, genetic and epigenetic alterations contribute only 1% and 1.8% respectively to the proposed mechanisms by which these 540 genes are disrupted in PDA. Ten of the 60 putative target genes which are a part of 5 of the 12 core signaling pathways in PDA, including K-Ras, were experimentally validated as specific HuR targets. Conclusion: HuR is an unprecedented regulatory protein of at least 5 critical signaling pathways in PDA. Targeting multiple core pathways in PDA through silencing HuR expression may be a potent therapeutic strategy to treat this disease.
Su1844 Pterostilbene Induces Mitochondrially-Derived Apoptosis in Pancreatic Cancer Cells by Increasing MnSOD Activity and Release of Cytochrome C and Smac/ DIABLO Denise E. McCormack, Debbie E. McDonald, David W. McFadden BACKGROUND: We have previously shown that Pterostilbene (3, 5- dimethoxy-4-hydroxystilbene), a compound found in blueberries, inhibits cell proliferation and promotes apoptosis in pancreatic cancer In Vitro by induction of mitochondrial membrane depolarization and caspase 3/7 activation. To further investigate the role of mitochondria in Pterostilbene-induced apoptosis in pancreatic cancer, we examined its effects on manganese superoxide dismutase (MnSOD) activity, Cytochrome C and Smac/DIABLO release. The mitochondrial enzyme MnSOD plays a critical role in regulation of cancer cell proliferation through an unknown mechanism. Smac/DIABLO is a mitochondrial protein that potentiates apoptosis. Both Smac/DIABLO and Cytochrome C have been shown to exit mitochondria and enter the cytosol during apoptosis. We hypothesized that Pterostilbene would increase MnSOD activity and cytosolic levels of Cytochrome C and Smac/DIABLO in a dose dependent manner. METHODS: MIA and PANC-1 cell lines were treated with 25 micromolar and 50 micromolar concentrations of Pterostilbene for 48hrs and quantitative MnSOD activity was measured by superoxide dismutase ELISA assay. In separate experiments, MIA and PANC-1 cell cells were treated with 25 micromolar, 50 micromolar and 75 micromolar concentrations of Pterostilbene for 24hrs and cytosolic extracts were analyzed for Cytochrome C and Smac/ DIABLO utilizing ELISA protocols. One way ANOVA and Tukey post-hoc analysis were used for statistical analysis. RESULTS: Pterostilbene increased enzymatic activity of MnSOD in both cell lines in a dose dependent manner (p <0.01). Pterostilbene treatment increased cystosolic levels of Cytochrome C in MIA cells at the 25 micromolar (p < 0.05) and 75 micromolar concentrations in PANC-1 cells (p < 0.05). Cystosolic levels of Smac/DIABLO increased in both MIA and PANC-1 cells with treatment at the 75 micromolar concentration of Pterostilbene (p <0.01). CONCLUSION: We have previously demonstrated that Pterostilbene, a natural plant-derived stilbene, inhibits pancreatic cancer In Vitro through activation of the mitochondrial apoptosis pathway. MnSOD, an inducible mitochondrial enzyme that converts superoxide anion to hydrogen peroxide, has an essential role in regulation of pancreatic cancer cell proliferation. The results of our current study demonstrate for the first time that Pterostilbene increases MnSOD activity in pancreatic cancer cells. In addition, Pterostilbene increases cytosolic levels of Cytochrome C and Smac/DIABLO in both cell lines, confirming mitochondrially derived apoptotic cell death. Further studies are ongoing to elucidate the intricate relationship between intrinsic apoptosis, MnSOD activity, and pancreatic cancer cell death upon Pterostilbene treatment.
Su1847 Changes in Neurotransmission via Alpha- and Beta-Receptors During Postoperative Ileus in Rat Circular Jejunal Muscle Michael S. Kasparek, Brigitte Goetz, Bernhard Stoklas, Petra Benhaqi, Mario H. Mueller, Martin E. Kreis Background Our aim was to: 1) investigate the role of α and β-receptors in control of contractile activity in rat circular jejunal muscle; 2) explore changes in adrenergic neurotransmission via these receptors during postoperative ileus (POI); 3) determine if these changes are paralleled by intramural inflammation and delayed intestinal transit. Methods Muscle strips (n=8/rat) from 6 male Sprague Dawley rats per group were studied in organ chambers. Groups: Naïve controls (NC), sham controls (SC) 24h after laparotomy, rats 12h (P12h), 1 (P1d), 3 (P3d), and 7days (P7d) after laparotomy and standardized small bowel manipulation to induce POI. After spontaneous contractile activity (g/mm2/min) was recorded, dose-response curves for phenylephrine (αa; α-agonist; 10-8-3x10-6M) and isoprenaline (βa; β-agonist; 3x10-10-10-7M) were established. Responses were repeated with tetrodotoxin (TTX; blocking enteric nerves; 10-6M), after precontraction with bethanechol (3x10-6M), and with phentolamine (α-anatagonist; 10-5M), or propranolol (β-antagonist; 5x10-6M). Intestinal transit was studied by charcoal transit (% of small bowel passed). Histology of jejunal whole mounts was performed for myeloperoxidase positive cells (MPO), macrophages, and mastcells (cells/mm2).Data: mean±SEM. Results Spontaneous contractile activity was increased in SC, P12h, and P7d (NC 1.3±0.3; SC 3.7±0.9; P12h 4.5±1.5; P7d 3.6±1.0; p<0.05), but not in P1d (1.7±0.4) and P3d (1.8±0.5; p=NS). αa and βa inhibited spontaneous contractile activity dose-dependently in all groups (p<0.05). In NC, TTX reduced αa-induced inhibition (p<0.05), but TTX had no effect on αa-responses in POI groups (p= NS). In contrast, TTX did not affect βa-response in NC (p=NS), but increased responses in POI groups (p<0.05). αa and βa-induced inhibition was reduced in P12h, P3d, and P7d and in all POI groups, respectively (p<0.05). Precontraction had no effect on αa and βaresponses (p=NS). Effects of αa and βa were blocked by phentolamine or propranolol (p<0.05). Intestinal transit was delayed in all POI animals and recovered over time (NC 53±3; P12h 22±2; P7d 44±2%; p<0.05), but was unaffected in SC (50±5%; p=NS). MPO positive cells and mastcells increased postoperatively and peaked in P1d (NC 14±2; P1d 763±48) and P12h (NC 9±1; P12h 700±79; both p<0.05), respectively; no effect was observed in SC (56±37 and 30±12, respectively; p=NS). Macrophages peaked in P3d (NC 367±41; P3d 1306±178; p<0.05); counts in SC and P12h were similar to NC (SC 395±82; P12h 706±19; p=NS). Conclusion Contractile activity can be inhibited predominantly via muscular α- and β-receptors. However, during POI long lasting changes in balance of muscular and neuronal α- and β-receptors occur that might participate in pathophysiology of POI. These changes are paralleled by intramural inflammation and impaired intestinal transit. DFG KA 2329/5-1
SSAT Abstracts
Su1845 Systemic Inflammation With Multiorgan Dysfunction is the Cause of Death in Murine Pancreatic Duct Ligation-Induced Acute Pancreatitis Zuobiao Yuan, David Meyerholz, Deborah Williard, Erik Twait, Kempuraj Duraisamy, Isaac Samuel Existing animal models of acute pancreatitis (e.g., cerulein, choline-deficient ethioninesupplemented diet) do not resemble gallstone pancreatitis as the etiologies are not analogous. Distal pancreatic duct ligation (PDL) more closely resembles early events in gallstone pancreatitis. We recently developed a novel murine model of PDL-induced acute pancreatitis associated with substantial mortality. Using this model, we previously showed that specific inhibition of the stress kinase ERK with In Vivo gene modulation significantly improves survival. In the present study we determine the cause of death in our murine model by serial examination of multiple parameters in three groups: a) Acute pancreatitis group had PDL; b) Hepatic obstruction group had bile duct ligation (BDL) without PDL; c) Sham operation group. The mice were observed for 15 days post-operatively. BDL and Sham controls had no mortality. Close to 100% mortality was seen in PDL-induced acute pancreatitis with most deaths occurring between day 2 and day 4. Characteristics of mice with acute pancreatitis included the following (ANOVA; P<0.05): ERK activation in the pancreas and distant organs; pancreatic neutrophil infiltration and acinar cell necrosis maximal on day 2; increased plasma IL-1β and TNF-α levels on day 2, that peaked on day 3, in parallel with worsening hypotension and bradycardia; bronchoalveolar lavage (BAL) fluid neutrophil count and IL1β level, and plasma aspartate aminotransferase (AST) level, also peaked on day 3; pulmonary neutrophil infiltration and plasma creatinine level peaked on day 4.. Liver injury evidenced by raised AST after hepatic obstruction was exacerbated by PDL. Increased plasma IL-1β and TNF-α on day 2 after BDL subsided thereafter. Although BDL was also associated with pulmonary neutrophil infiltration it was not associated with increased IL-1β or neutrophils in BAL fluid. BDL-induced renal tubular damage was not associated with raised plasma creatinine. Our findings indicate that the high mortality rate seen in PDL-induced acute pancreatitis in mice is associated with progressive systemic increase of inflammatory cytokine levels, cardiovascular instability, acute lung injury, liver injury, and renal dysfunction, suggesting that systemic inflammation with multiorgan failure is the proximate cause of death in this experimental model. Lung and renal injury as observed by morphology after hepatic obstruction alone is not associated with systemic inflammation or death. In conclusion, systemic inflammation with multiorgan dysfunction causes death in pancreatic duct ligation-induced acute pancreatitis in mice. This experimental model is a useful analogy of severe gallstone pancreatitis to investigate disease pathogenesis and to evaluate novel therapeutic strategies.
SSAT Abstracts
Su1848 Central Vagal Activation During Early Postoperative Ileus in the Mouse Mia Karpitschka, Mario H. Mueller, Michael S. Kasparek, Jorg Glatzle, Martin E. Kreis Introduction: Postoperative ileus (POI) involves reflex inhibition of intestinal motility and a subsequent intestinal inflammatory response that is characterized by efferent vagal modulation. However, the role of central vagal afferents in the early phase of POI is unknown. We, therefore, aimed to explore central vagal afferent nerve activation early during POI. Material and Methods: C57BL/6 mice were vagotomized 3-4 days prior to ileus experiments, while control animals received a sham operation without vagotomy. For ileus experiments, laparotomy was either followed by standardized small bowel manipulation to induce POI or sham treatment for control. Then, after 3h or 9h, the brain was removed, fixed and Fosimmunohistochemistry was performed to determine neuronal activation in the vagal nucleus of the solitary tract (NTS) and the area postrema. Each subgroup contained an n of 6. Data were analyzed by two-way ANOVA. Results: The number of Fos-positive neurons in the
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