- Email: [email protected]
S1640 Combination Therapy of Ecabet Sodium and Proton Pump Inhibitor (PPI) Compared with PPI Alone for Endoscopic Submucosal Dissection (ESD) -Induced Ulcer in Gastric Cancer: Prospective Randomized Study
AGA Abstracts
levels by both pre- and post-treatments of RVT. Increased collagen levels in the salinetreated ulcer groups (p<0.001) were also decreased by 10-days RVT treatment (p<0.001). Conclusion: These results demonstrate that RVT has both protective and therapeutic effects on oxidative gastric damage by suppressing pro-inflammatory cascades, including the activation of pro-inflammatory cytokines, accumulation of neutrophils, and release of oxygenderived free radicals.
of 5-LOX and cysLT-1R in the gastric mucosa were examined by RT-PCR. Results: I/R produced hemorrhagic lesions in the gastric mucosa. The severity of I/R-induced gastric lesions was dose- dependently reduced by prior administration of pranlukast. Likewise, pretreatment of the animals with TMK-688 also significantly prevented the development of I/R-induced gastric lesions. By contrast, these lesions were markedly aggravated by pretreatment with indomethacin, and this response was significantly abrogated by the co- administration of prostaglandin E2 or TMK-688. The expression of cysLT-1R mRNA was markedly up-regulated in the gastric mucosa following IR but not in the stomach subjecting to either ischemia or sham-operation alone. I/R only slightly increased the mucosal levels of cysLTs in the stomach, yet this increase during I/R was markedly enhanced when the animals were pretreated with indomethacin. The increased cysLT biosynthetic response to indomethacin during I/R was totally attenuated by TMK-688. In addition, neither pranlukast nor TMK688 had any effect on acid secretion in normal mice. Conclusion: These results suggested that cysLTs play a crucial role in the pathogenesis of I/R-induced gastric lesions, and this action is mediated by cysLT-R type 1. In addition, the aggravation by indomethacin of I/R-induced gastric lesions may be accounted for by the up-regulation of cysLTs production as well as cysLT-R1 expression.
S1639 Biphasic Effect of Japanese Horseradish and Mustard On Gastric Ulcerogenic Responses in Rats Nahoko Izumi, Shusaku Hayashi, Tetsuya Sugihara, Shinichi Kato, Koji Takeuchi Background/Aim: The intake of Japanese mustard and horseradish as food condiments shows an orexi-genic effect, yet the ingestion in excess induces acid indigestion or intestinal catarrh. They are structurally related to allyl isothiocyanate that is known to stimulate transient receptor potential subtype A1 (TRPA1), a non-selective cation channel invariably co-expressed with TRPV1, the capsaicin receptor. However, the effects of horseradish and mustard on the mucosal defense in the stomach remain unknown. In the present study, we examined the effects of horseradish and mustard on gastric lesions induced by HCl/EtOH, indomethacin or cold-restraint stress in rats and investigated the mechanisms involved in these responses. Methods: Male SD rats were used after 18 h fasting. Animals were given HCl/EtOH (60% EtOH in 150 mM HCl, PO) or indomethacin (30 mg/kg, SC) or subjected to cold-restraint stress (Ballman cage/10°C) and killed 1, 4 or 6 h later, respectively. Horseradish, mustard and allyl isothiocyanate were given 30 min before the administration of HCl/EtOH or indomethacin or the onset of cold-restraint stress. Gastric secretion was determined in pylorus-ligated rats while gastric mucosal blood flow (GMBF) is measured by a laser Doppler flowmeter in urethane anesthetized rats. Results: Hemorrhagic lesions were induced in the stomach by administration of HCl/EtOH or indomethacin or subjecting to cold-restraint stress. Pretreatment with horseradish, mustard or allyl isothiocyanate significantly and dosedependently inhibited gastric lesions induced by HCl/EtOH. However, all of these agents significantly and dose- dependently aggravated the development of gastric lesions in response to indomethacin or cold-restraint stress. The protective effects against HCl/EtOH-induced lesions were not reversed by either indomethacin (5 mg/kg, SC), L-NAME (20 mg/kg, SC) or chemical ablation of sensory neurons. These agents increased GMBF by mucosal application with a drop in gastric potential difference. These agents increased pepsin but not acid secretion in pylorus- ligated rats. Conclusion: These results suggest that Japanese horseradish and mustard exert a biphasic effect on gastric ulcerogenic response depending on a lesion model; a protection against HCl/ EtOH-induced damage and an aggravation of lesions induced by indomethacin or cold-restraint stress, although none of these effects is related to TRPA1 activation. It is assumed that their protective effect is partly accounted for by increase of GMBF, while the aggravating effect is partly related to the topical irritative action as well as the stimulatory effect on pepsin secretion.
S1642 CD2 Associated Protein Expression At Plasma Membrane Is Increased and Associates with Cell Junction Disruption After Extracellular Ca2+ Depletion in Rat Gastric Epithelia Harri Mustonen, Tuula Kiviluoto, Pauli A. Puolakkainen, Eero O. Kivilaakso Aim: We have here explored the detachment of gastric epithelial cells, and thereby elucidated the regulation mechanisms of epithelial cell junctions. This information is essential to understanding of the initiation of migration and the effects of different agents affecting the cell-cell junctions, such as barrier braking agents and luminal acid. This was accomplished by investigating the detachment of cells after extracellular Ca2+-depletion. Subcellular localization of CD2AP, E-cadherin, p120 catenin (p120ctn) and actin during this process was also studied. Methods: The subcellular localization of CD2AP, p120ctn, actin and E-cadherin during different phases of cellular detachment induced by extracellular calcium depletion was studied by immunocytochemistry in rat gastric mucosal epithelia (RGM-1). Cytoplasmic and membrane fractions were analyzed with western blotting. Also intracellular calcium activity and transepithelial permeability were measured during extracellular calcium depletion. Results: After calcium removal, CD2AP co-localized with the widened areas of actin belts just adjacent to the sites where separation of adhesion belts occurred. Intracellular calcium activity began to increase immediately after calcium depletion and this increase was inhibited with the calcium antagonist TMB-8. The effect of extracellular calcium depletion on transepithelial permeability was much more profound when intracellular calcium signaling was inhibited with TMB-8 or with the calcium binding agent bapta treatment. Reduction of CD2AP expression with siRNA technique decreased moderately the increase in transepithelial permeability induced by extracellular calcium removal. Conclusions: Intracellular calcium signaling is associated with suppression of cell-cell junction disruption and CD2AP contributes to the disruption of cell-cell junctions after extracellular calcium removal. Inhibition of CD2AP function is known to decrease migration rate and our results suggests that CD2AP might be involved already at the initiation phase of migration, namely at the cell-cell detachment phase.
S1640 Combination Therapy of Ecabet Sodium and Proton Pump Inhibitor (PPI) Compared with PPI Alone for Endoscopic Submucosal Dissection (ESD) -Induced Ulcer in Gastric Cancer: Prospective Randomized Study Shigenaga Matsui, Masatoshi Kudo, Mumon Okada, Yutaka Asakuma, Tsutomu Ichikawa, Masanori Kawasaki
S1643
Backgroud and aim: Ecabet sodium (ES) is one of the mucoprotective agent, and is widely employed treatment of gastric ulcer in Japan. In this study ,we evaluated prospectively the additive benefit of ES in combination with proton pump inhibitor (PPI, rabeprazole) for gastric ulcer after endoscopic submucosal dissection (ESD). Methods: Fifty patients after ESD in early gastric cancer were randomly assigned to receive either PPI with ES (P/ES group, n=25) or PPI alone (PPI group, n=25) for 8 weeks. No significant difference was observed between the two groups in patient characteristics. Four and 8 weeks after ESD, ulcer size and stage were compared between two groups by endoscopy. Results: At 4, and 8 weeks, complete healing rates were significantly higher in the P/ES group (47.8%,100%) than in the PPI group (9.1%,81.8%), respectively (p<0.01, p<0.05). At 4, and 8 weeks, diminution rates of ESD-induced ulcer size were significantly higher in the P/ES group (96.6%, 100%) than in the PPI group (83.7%,99.7%), respectively (p<0.005, p<0.005). One patient in the PPI group occurred hemorrhage from ESD-induced ulcer. Five patients in the PPI group had bizarre elevated lesions of overgrowth with granulation tissue. Conclusion: ES in combination with PPI is useful for facilitating the healing of ESD-induced ulcer, and can improve the quality of ulcer healing.
EGFR Controls Flat Dysplastic ACF Development and Colon Cancer Progression in the Rat Azoxymethane Model Urszula Dougherty, Amikar Sehdev, Sonia R. Cerda, Reba Mustafi, Nathaniel Little, Weihua Yuan, Sujatha Jagadeeswaran, Anusara Chumsangsri, Jorge-Shmuel Delgado, Maria Tretiakova, Loren Joseph, John Hart, Ezra Cohen, Lata M. Aluri, Alessandro Fichera, Marc Bissonnette Purpose: Colonic carcinogenesis involves derangements in epidermal growth factor receptor signals that control crypt cell growth. In prior studies we showed that EGFR signals were up-regulated in human aberrant crypt foci (ACF), putative precursors of colon cancer. The azoxymethane (AOM) model of experimental colon cancer recapitulates many aspects of the human malignancy. Recent studies indicate that flat appearing dysplastic ACF with β catenin accumulation are tumor precursors in this model. In this study we investigated the role of EGFR in the development of flat dysplastic ACF and colon cancer progression. Experimental Design: Fisher-344 rats received AOM or saline weekly x 2 wks and two wks later were fed standard AIN-76A chow, or chow supplemented with the EGFR inhibitor Gefitinib (10 mg/kg body wt) for 44 wks. Normal colon, flat ACF and tumors were examined by immunostaining and Western blotting for EGFR effector signals and for proliferation (Ki67), apoptosis (caspase-3) and angiogenesis (nestin-1). Results were quantified by computer-assisted image analysis. K ras mutations were assessed by PCR and mRNA measured by real time PCR. Results: EGFR inhibition with Gefitinib decreased the incidence of flat dysplastic ACF from 66% to 36% and tumors from 71% to 22% (p<0.05). In flat ACF, this inhibitor reduced over-expressions of cyclin D1 and Cox-2 and reduced up-regulations of c-Jun, FosB, pSTAT3 and pC/EBPβ. The latter transcription factors are potential regulators of cyclin D1 and Cox-2. In colonic tumors, Gefitinib inhibited activations of ERK, Src and AKT pathways. EGFR blockade also significantly decreased tumor angiogenesis and proliferation as well as cancer progression, while increasing apoptosis (p<0.05). Conclusions: We have for the first time demonstrated that EGFR promotes the development of flat dysplastic ACF and the progression of malignant colonic tumors. Furthermore, we have mechanistically identified several transcription factors and their targets as EGFR effectors in colonic carcinogenesis.
S1641 Pathogenic Importance of Cysteinyl Leukotrienes in Development of Gastric Lesions Induced By Ischemia/ Reperfusion in Mice Yoshino Komatsu, Yuka Nakamori, Tohru Kotani, Koji Takeuchi Background/Aim: Cysteinyl leukotrienes (cysLTs), produced from arachidonic acid by 5lipoxygenase (5-LOX), are known to play an important role in a variety of inflammatory responses in the body. Recent study showed that the cysLT receptor (cysLT-R) antagonist prevented gastric lesions induced by ethanol or nonsteroidal anti- inflammatory drugs. However, the roles cysLTs and their receptors play in the development of ischemia/reperfusion (I/R)-induced gastric injury remain unexplored. In the present study, we examined the roles of cysLTs in gastric ulcerogenic response to I/R in mice. Methods: Experiments were performed in male C57BL/6J mice after 18 h fasting. Under urethane anesthesia (1.25 g/kg, IP), the celiac artery was clamped for 30 min, followed by reperfusion by removing the clamp, and the stomachs were examined for lesions 60 min thereafter. Indomethacin (a cyclooxygenase inhibitor, 5 mg/kg), TMK-688 (a 5-LOX inhibitor, 30 mg/kg), or pranlukast [a cysLT-R type 1 (cysLT-R1) antagonist, 1~10 mg/kg] was given PO 60 min before the ischemia. Levels of cysLTs in the gastric mucosa was measured by EIA. Gene expressions
AGA Abstracts
A-240
levels by both pre- and post-treatments of RVT. Increased collagen levels in the salinetreated ulcer groups (p<0.001) were also decreased by 10-days RVT treatment (p<0.001). Conclusion: These results demonstrate that RVT has both protective and therapeutic effects on oxidative gastric damage by suppressing pro-inflammatory cascades, including the activation of pro-inflammatory cytokines, accumulation of neutrophils, and release of oxygenderived free radicals.
of 5-LOX and cysLT-1R in the gastric mucosa were examined by RT-PCR. Results: I/R produced hemorrhagic lesions in the gastric mucosa. The severity of I/R-induced gastric lesions was dose- dependently reduced by prior administration of pranlukast. Likewise, pretreatment of the animals with TMK-688 also significantly prevented the development of I/R-induced gastric lesions. By contrast, these lesions were markedly aggravated by pretreatment with indomethacin, and this response was significantly abrogated by the co- administration of prostaglandin E2 or TMK-688. The expression of cysLT-1R mRNA was markedly up-regulated in the gastric mucosa following IR but not in the stomach subjecting to either ischemia or sham-operation alone. I/R only slightly increased the mucosal levels of cysLTs in the stomach, yet this increase during I/R was markedly enhanced when the animals were pretreated with indomethacin. The increased cysLT biosynthetic response to indomethacin during I/R was totally attenuated by TMK-688. In addition, neither pranlukast nor TMK688 had any effect on acid secretion in normal mice. Conclusion: These results suggested that cysLTs play a crucial role in the pathogenesis of I/R-induced gastric lesions, and this action is mediated by cysLT-R type 1. In addition, the aggravation by indomethacin of I/R-induced gastric lesions may be accounted for by the up-regulation of cysLTs production as well as cysLT-R1 expression.
S1639 Biphasic Effect of Japanese Horseradish and Mustard On Gastric Ulcerogenic Responses in Rats Nahoko Izumi, Shusaku Hayashi, Tetsuya Sugihara, Shinichi Kato, Koji Takeuchi Background/Aim: The intake of Japanese mustard and horseradish as food condiments shows an orexi-genic effect, yet the ingestion in excess induces acid indigestion or intestinal catarrh. They are structurally related to allyl isothiocyanate that is known to stimulate transient receptor potential subtype A1 (TRPA1), a non-selective cation channel invariably co-expressed with TRPV1, the capsaicin receptor. However, the effects of horseradish and mustard on the mucosal defense in the stomach remain unknown. In the present study, we examined the effects of horseradish and mustard on gastric lesions induced by HCl/EtOH, indomethacin or cold-restraint stress in rats and investigated the mechanisms involved in these responses. Methods: Male SD rats were used after 18 h fasting. Animals were given HCl/EtOH (60% EtOH in 150 mM HCl, PO) or indomethacin (30 mg/kg, SC) or subjected to cold-restraint stress (Ballman cage/10°C) and killed 1, 4 or 6 h later, respectively. Horseradish, mustard and allyl isothiocyanate were given 30 min before the administration of HCl/EtOH or indomethacin or the onset of cold-restraint stress. Gastric secretion was determined in pylorus-ligated rats while gastric mucosal blood flow (GMBF) is measured by a laser Doppler flowmeter in urethane anesthetized rats. Results: Hemorrhagic lesions were induced in the stomach by administration of HCl/EtOH or indomethacin or subjecting to cold-restraint stress. Pretreatment with horseradish, mustard or allyl isothiocyanate significantly and dosedependently inhibited gastric lesions induced by HCl/EtOH. However, all of these agents significantly and dose- dependently aggravated the development of gastric lesions in response to indomethacin or cold-restraint stress. The protective effects against HCl/EtOH-induced lesions were not reversed by either indomethacin (5 mg/kg, SC), L-NAME (20 mg/kg, SC) or chemical ablation of sensory neurons. These agents increased GMBF by mucosal application with a drop in gastric potential difference. These agents increased pepsin but not acid secretion in pylorus- ligated rats. Conclusion: These results suggest that Japanese horseradish and mustard exert a biphasic effect on gastric ulcerogenic response depending on a lesion model; a protection against HCl/ EtOH-induced damage and an aggravation of lesions induced by indomethacin or cold-restraint stress, although none of these effects is related to TRPA1 activation. It is assumed that their protective effect is partly accounted for by increase of GMBF, while the aggravating effect is partly related to the topical irritative action as well as the stimulatory effect on pepsin secretion.
S1642 CD2 Associated Protein Expression At Plasma Membrane Is Increased and Associates with Cell Junction Disruption After Extracellular Ca2+ Depletion in Rat Gastric Epithelia Harri Mustonen, Tuula Kiviluoto, Pauli A. Puolakkainen, Eero O. Kivilaakso Aim: We have here explored the detachment of gastric epithelial cells, and thereby elucidated the regulation mechanisms of epithelial cell junctions. This information is essential to understanding of the initiation of migration and the effects of different agents affecting the cell-cell junctions, such as barrier braking agents and luminal acid. This was accomplished by investigating the detachment of cells after extracellular Ca2+-depletion. Subcellular localization of CD2AP, E-cadherin, p120 catenin (p120ctn) and actin during this process was also studied. Methods: The subcellular localization of CD2AP, p120ctn, actin and E-cadherin during different phases of cellular detachment induced by extracellular calcium depletion was studied by immunocytochemistry in rat gastric mucosal epithelia (RGM-1). Cytoplasmic and membrane fractions were analyzed with western blotting. Also intracellular calcium activity and transepithelial permeability were measured during extracellular calcium depletion. Results: After calcium removal, CD2AP co-localized with the widened areas of actin belts just adjacent to the sites where separation of adhesion belts occurred. Intracellular calcium activity began to increase immediately after calcium depletion and this increase was inhibited with the calcium antagonist TMB-8. The effect of extracellular calcium depletion on transepithelial permeability was much more profound when intracellular calcium signaling was inhibited with TMB-8 or with the calcium binding agent bapta treatment. Reduction of CD2AP expression with siRNA technique decreased moderately the increase in transepithelial permeability induced by extracellular calcium removal. Conclusions: Intracellular calcium signaling is associated with suppression of cell-cell junction disruption and CD2AP contributes to the disruption of cell-cell junctions after extracellular calcium removal. Inhibition of CD2AP function is known to decrease migration rate and our results suggests that CD2AP might be involved already at the initiation phase of migration, namely at the cell-cell detachment phase.
S1640 Combination Therapy of Ecabet Sodium and Proton Pump Inhibitor (PPI) Compared with PPI Alone for Endoscopic Submucosal Dissection (ESD) -Induced Ulcer in Gastric Cancer: Prospective Randomized Study Shigenaga Matsui, Masatoshi Kudo, Mumon Okada, Yutaka Asakuma, Tsutomu Ichikawa, Masanori Kawasaki
S1643
Backgroud and aim: Ecabet sodium (ES) is one of the mucoprotective agent, and is widely employed treatment of gastric ulcer in Japan. In this study ,we evaluated prospectively the additive benefit of ES in combination with proton pump inhibitor (PPI, rabeprazole) for gastric ulcer after endoscopic submucosal dissection (ESD). Methods: Fifty patients after ESD in early gastric cancer were randomly assigned to receive either PPI with ES (P/ES group, n=25) or PPI alone (PPI group, n=25) for 8 weeks. No significant difference was observed between the two groups in patient characteristics. Four and 8 weeks after ESD, ulcer size and stage were compared between two groups by endoscopy. Results: At 4, and 8 weeks, complete healing rates were significantly higher in the P/ES group (47.8%,100%) than in the PPI group (9.1%,81.8%), respectively (p<0.01, p<0.05). At 4, and 8 weeks, diminution rates of ESD-induced ulcer size were significantly higher in the P/ES group (96.6%, 100%) than in the PPI group (83.7%,99.7%), respectively (p<0.005, p<0.005). One patient in the PPI group occurred hemorrhage from ESD-induced ulcer. Five patients in the PPI group had bizarre elevated lesions of overgrowth with granulation tissue. Conclusion: ES in combination with PPI is useful for facilitating the healing of ESD-induced ulcer, and can improve the quality of ulcer healing.
EGFR Controls Flat Dysplastic ACF Development and Colon Cancer Progression in the Rat Azoxymethane Model Urszula Dougherty, Amikar Sehdev, Sonia R. Cerda, Reba Mustafi, Nathaniel Little, Weihua Yuan, Sujatha Jagadeeswaran, Anusara Chumsangsri, Jorge-Shmuel Delgado, Maria Tretiakova, Loren Joseph, John Hart, Ezra Cohen, Lata M. Aluri, Alessandro Fichera, Marc Bissonnette Purpose: Colonic carcinogenesis involves derangements in epidermal growth factor receptor signals that control crypt cell growth. In prior studies we showed that EGFR signals were up-regulated in human aberrant crypt foci (ACF), putative precursors of colon cancer. The azoxymethane (AOM) model of experimental colon cancer recapitulates many aspects of the human malignancy. Recent studies indicate that flat appearing dysplastic ACF with β catenin accumulation are tumor precursors in this model. In this study we investigated the role of EGFR in the development of flat dysplastic ACF and colon cancer progression. Experimental Design: Fisher-344 rats received AOM or saline weekly x 2 wks and two wks later were fed standard AIN-76A chow, or chow supplemented with the EGFR inhibitor Gefitinib (10 mg/kg body wt) for 44 wks. Normal colon, flat ACF and tumors were examined by immunostaining and Western blotting for EGFR effector signals and for proliferation (Ki67), apoptosis (caspase-3) and angiogenesis (nestin-1). Results were quantified by computer-assisted image analysis. K ras mutations were assessed by PCR and mRNA measured by real time PCR. Results: EGFR inhibition with Gefitinib decreased the incidence of flat dysplastic ACF from 66% to 36% and tumors from 71% to 22% (p<0.05). In flat ACF, this inhibitor reduced over-expressions of cyclin D1 and Cox-2 and reduced up-regulations of c-Jun, FosB, pSTAT3 and pC/EBPβ. The latter transcription factors are potential regulators of cyclin D1 and Cox-2. In colonic tumors, Gefitinib inhibited activations of ERK, Src and AKT pathways. EGFR blockade also significantly decreased tumor angiogenesis and proliferation as well as cancer progression, while increasing apoptosis (p<0.05). Conclusions: We have for the first time demonstrated that EGFR promotes the development of flat dysplastic ACF and the progression of malignant colonic tumors. Furthermore, we have mechanistically identified several transcription factors and their targets as EGFR effectors in colonic carcinogenesis.
S1641 Pathogenic Importance of Cysteinyl Leukotrienes in Development of Gastric Lesions Induced By Ischemia/ Reperfusion in Mice Yoshino Komatsu, Yuka Nakamori, Tohru Kotani, Koji Takeuchi Background/Aim: Cysteinyl leukotrienes (cysLTs), produced from arachidonic acid by 5lipoxygenase (5-LOX), are known to play an important role in a variety of inflammatory responses in the body. Recent study showed that the cysLT receptor (cysLT-R) antagonist prevented gastric lesions induced by ethanol or nonsteroidal anti- inflammatory drugs. However, the roles cysLTs and their receptors play in the development of ischemia/reperfusion (I/R)-induced gastric injury remain unexplored. In the present study, we examined the roles of cysLTs in gastric ulcerogenic response to I/R in mice. Methods: Experiments were performed in male C57BL/6J mice after 18 h fasting. Under urethane anesthesia (1.25 g/kg, IP), the celiac artery was clamped for 30 min, followed by reperfusion by removing the clamp, and the stomachs were examined for lesions 60 min thereafter. Indomethacin (a cyclooxygenase inhibitor, 5 mg/kg), TMK-688 (a 5-LOX inhibitor, 30 mg/kg), or pranlukast [a cysLT-R type 1 (cysLT-R1) antagonist, 1~10 mg/kg] was given PO 60 min before the ischemia. Levels of cysLTs in the gastric mucosa was measured by EIA. Gene expressions
AGA Abstracts
A-240