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Abstracts / Pancreatology 16 (2016) S1eS192
A definitive diagnosis of pancreatic neuroendocrine tumor (PNET) grade 2 with a peritoneal dissemination was made.
as PEGPH20 (Cancer Science, in press). These therapeutic model targeting HA could lead to a breakthrough for the fight against this highly lethal neoplasm.
P-295. Antitumor effect of photodynamic therapy with a novel oligosaccharide-conjugated chlorin for pancreatic cancer Akihisa Kato 1, Hiromi Kataoka 1, Shigenobu Yano 2, Makoto Natsume 1, Shuichiro Umemura 1, Michihiro Yoshida 1, Yuji Nishi 1, Hiromu Kondo 1, Tesshin Ban 1, Itaru Naitoh 1, Kazuki Hayashi 1, Takashi Joh 1
P-297. Development of a novel REIC/Dkk-3-encoding adenoviral agent for the treatment of pancreatic cancer Daisuke Uchida, Hidenori Shiraha, Hironari Kato, Hiroyuki Okada Department of Gastroenterology, Okayama University Hospital, Japan
1
Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Japan 2 Graduate School of Materials Science, Nara Institute of Science and Technology, Japan Background/aims: Photodynamic therapy (PDT) has gained considerable attention as an alternative to management of cancer. We synthesized glucose-conjugated chlorin (G-chlorin), which is selectively taken up by gastrointestinal cancer cells because of Warburg's effect. Additionally, we developed oligosaccharide-conjugated chlorin (O-chlorin) to overcome the hydrophobicity of G-chlorin and investigated its effect for pancreatic cancer. Methods: O-chlorin was administered to pancreatic cancer cell lines (AsPC1, BxPC3 and Panc1), followed by irradiation of 660nm LED light, and the effects were compared with that of Talaporfin, which is clinically used in Japan. The cytotoxic effect of O-chlorin PDT was determined by evaluating cell viability, apoptosis and generation of reactive oxygen species (ROS). Moreover, the subcellular localization of O-chlorin was observed by confocal microscopy. Results: O-chlorin was 17-35 times more cytotoxic to pancreatic cancer cells than Talaporfin. Moreover, O-chlorin PDT induced apoptosis as indicated by caspase-3/7 activity analysis, and DCFH assay revealed intracellular ROS level was increased in O-chlorin PDT-treated cells. Confocal microscopy showed that O-chlorin tended to accumulate mainly in lysosomes and Golgi. Conclusions: The present study indicated that PDT with water-soluble O-chlorin, which is a candidate for next generation photosensitizer, showed anti-tumor potential for pancreatic cancer.
Introduction: The reduced expression in immortalized cells (REIC)/ dickkopf3 (Dkk3) is a tumor suppressor gene that is downregulated in various cancers. We reported the efficacy of REIC gene therapy with an adenoviral vector (Ad-CAG-REIC) in pancreatic cancer. Based on these backgrounds, we developed a novel gene expression system named the super gene expression (SGE) system and re-constructed the Ad-SGE-REIC with this gene expression system. In the current study, we assessed the therapeutic effects of Ad-SGE-REIC in pancreatic cancer. Methods: Human pancreatic cancer cell lines (ASPC1, and MIAPaCa2) were used in this study. REIC/Dkk-3 expression was assessed by immunoblotting. Cells were treated with Ad-CAG-REIC and Ad-SGE-REIC. The relative cell viability was examined by MTT assay. We established the mouse xenograft model, and the anti-tumor effects of Ad-REIC treatment was analyzed. Results: The REIC/Dkk-3 expression was decreased in pancreatic cancer cell lines. Ad-SGE-REIC significantly increased the REIC protein expression in comparison with Ad-CAG-REIC. Ad-CAG-REIC treatment reduced the cell viability by 62.0% and 39.6% in ASPC1 and MIAPaCa2, respectively. As expected, Ad-SGE-REIC reduced the cell viability by 83.1% and 67.2% respectively. Ad-SGE-REIC achieved superior tumor growth inhibition (50.0%) in comparison with Ad-CAG-REIC (24.9%) in the mouse xenograft model. Conclusion: REIC gene therapy using Ad-SGE-REIC could be an innovative therapeutic tool for pancreatic cancer.
P-298.
P-296. The role of hyaluronan in pancreatic cancer biology and therapy Norihiro Sato, Shiro Kohi, Atsuhiro Koga, Keiji Hirata Department of Surgery 1, University of Occupational and Environmental Health, Japan Hyaluronan (HA), a major component of extracellular matrices, is involved in the variety of cellular processes, including adhesion, migration, proliferation, invasion, and angiogenesis. We have reported the following novel findings regarding the clinical and functional role of HA in pancreatic ductal adenocarcinoma (PDAC). (1) HA is overexpressed in many PDAC tissues and correlates with poor prognosis (PLoS One, 2013). (2)One of the HA receptors, RHAMM, is overexpressed in PDAC (J Cancer, 2015). (3) HA is secreted from PDAC cells themselves and its production is regulated by epigenetic mechanisms (Clin Exp Metastasis, 2015). (4) HA is also secreted from fibroblasts derived from PDAC tissue. (5) In PDAC, expression of hyaluronidase (HA-degrading enzyme), as well as HA synthase (HA-synthesizing enzyme), is increased (in submission). (6) HA (particularly, lowmolecular-weight HA) stimulates PDAC cell migration, whereas 4-methylumbelliferone (4-MU), a HA inhibitor, suppresses the migration of treated cells (Oncotarget, 2016). These findings suggest that HA could be an ideal therapeutic target. We propose three different strategies targeting HA (Figure): ①inhibiting HA synthesis (by for example, 4-MU), ②blocking HA signaling pathways, and ③depleting stromal HA by enzymatic agents, such
A novel tactics for the treatment of pancreatic adenocarcinoma by targeting extracellular matrix Akiko Suto, Daisuke Kudo, Yoshikazu Toyoki, Keinosuke Ishido, Taiichi Wakiya, Hayato Nagase, Tatsuya Yoshida, Kenichi Hakamada Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine Purpose: Pancreatic adenocarcinoma still remains one of the most malignant neoplasms, the 5-year survival rate of patients with this disease is less than 5%. Poverty of survival are caused by nonresponsiveness for the treatment including surgery, chemotherapy, and radiation therapy. Recently, it has been reported hyaluronan contents in the pancreatic adenocarcinoma correlates closely with the worse prognosis. We have been reported 4-methylumbelliferone (MU) suppressed hyaluronan synthesis of human pancreatic cancer cell line, MIA PaCa-2, both of in vitro and in vivo. In this study, we investigated anticancer effect of MU for the several kinds of human pancreatic adenocarcinoma cell lines. Methods: We examined the effect of 4-MU on cell proliferation, HA synthesis, and formation of extracellular matrix (ECM) area in the four kinds of human pancreatic adenocarcinoma cell lines, MIA PaCa-2, AsPC-1, BxPC-3 and PANC-1. HA surrounding the cells were quantitatively measured using a sandwich binding protein assay kit and immunohistochemically detected. ECM around the each cells was visualized by a particle exclusion assay. Results: Cell proliferation were suppressed by 4-MU, significantly. The amount of HA around the cells were decreased by 4-MU. The