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Bcl-xL overexpression promotes Kras-mutated pancreatic ductal adenocarcinoma by inhibiting oncogene-induced senescence
Abstracts / Pancreatology 16 (2016) S1eS192
adenocarcinoma (PDAC) patients and 6,111 controls in the context of the Pancreatic Disease Research (PANDoRA) consortium. We found that six SNPs showed a statistically significant association (p<0.05) with PDAC risk. In particular, rs3217992 was associated with an increased pancreatic cancer risk (ORhet¼1.14, 95% CI 1.01-1.27, p¼0.026, ORhom¼1.30, 95% CI 1.12-1.51, p¼4.9x10-4). This pleiotropic variant is reported to be a mir-SNP that, by changing the binding site of one or more miRNAs, could influence the normal cell cycle progression and in turn increase PDAC risk. In conclusion, we observed a novel association in a pleiotropic region that has been found to be of key relevance in the susceptibility to various types of cancer and diabetes.
F-026. Circulating tumor cluster is a prognostic marker in patients with pancreatic ductal adenocarcinoma Ming-Chu Chang 1, Ying-Chih Chang 2, Yung-Ming Jeng 3, Ching-Yao Yang 4, Yu-Wen Tien 4, Shih-Hung Yang 5, Eva Y.H.P. Lee 6, Wen-Hwa Lee 7, 8, Yu-Ting Chang 1 1 Department of Internal Medicine, National Taiwan University Hospital, Taiwan 2 Genomics Research Center, Academia Sinica, Taiwan 3 Department of Pathology, National Taiwan University Hospital, Taiwan 4 Department of Surgery, National Taiwan University Hospital, Taiwan 5 Department of Oncology, National Taiwan University Hospital, Taiwan 6 Department of Biological Chemistry, University of California, United States 7 Genomics Research Center, Academia Sinica, Taiwan 8 Graduate Institute of Clinical Medicine, China Medical University, China
Background: Characterization of circulating tumor cells has been used to provide prognostic, predictive and pharmacodynamic information in many different cancers. However, the clinical significance of circulating tumor cluster in patients with pancreatic ductal adenocarcinoma (PDAC) has yet to be determined. Methods: In this prospective study, circulating tumor cluster was enumerated in the peripheral blood of 63 patients with PDAC before treatment using anti-EpCAM-conjugated supported lipid bilayer coated microfluidic chips. Associations of circulating tumor cluster with patients' clinical factors and prognosis were determined. Results: Circulating tumor cluster was present in 81% (51 of 63) patients with mean±SD:29.7±1101.4. Circulating tumor cluster was an independent prognostic factor of overall survival and progression free survival (PFS). Patients were stratified into unfavorable and favorable circulating tumor cluster groups based on cluster numbers more or less than 30 per 2 ml blood respectively. Patients with baseline unfavorable cluster, when compared with patients with favorable cluster, had shorter PFS (2.7 vs. 12.1 months; P < 0.0001) and overall survival (6.4 vs. 19.8 months; P < 0.0001). Differences persisted if we stratified patients into early and advanced diseases. The number of cluster before treatment was an independent predictor of PFS and overall survival after adjustment for clinically significant factors. Conclusions: The number of circulating tumor cluster before treatment is an independent predictor of PFS and overall survival in patients with PDAC.
F-027. Plasma DNA genotyping using digital PCR: Novel diagnostic tool for early detection of pancreatic cancer Yusuke Mizukami 1, Yusuke Ono 1, Hidenori Karasaki 1, Kazuya Koizumi 2, Shingo Asahara 3, Kuniyuki Takahashi 4, Hiroyuki Maguchi 4 1 Center for Clinical and Biomedical Research, Sapporo Higashi Tokushukai Hospital, Japan 2 Center for Gastroenterology, Shonan Kamakura General Hospital, Japan
3 4
S53
Department of Gastroenterology, Chiba Tokushukai Hospital, Japan Center for Gastroenterology, Teine Keijinkai Hospital, Japan
The genetic alterations that are responsible for the initiation and progression of pancreatic ductal adenocarcinoma (PDA) could serve as a new generation of biomarkers for early diagnosis of the tumor. Recent technologies are emerging to allow genotyping of cell-free plasma DNA (cfDNA) shed from tumors into the general circulation. These tools offer the promise of sensitive and non-invasive methods for monitoring cancer genetics. There are two main types of pathologically and genetically distinct precursors for PDA, pancreatic intraepithelial neoplasias (PanINs) and intraductal papillary mucinous cystic neoplasias (IPMNs), and the key driver mutations in KRAS and/or GNAS regulate the diseases initiation and progression. We established protocols for super-sensitive and absolute quantification of very low concentrations of the target mutant alleles using a droplet digital PCR platform (Bio-Rad;QX200). Detection limit using specific primer/probe sets for each mutation were assessed to be 0.05% based on preliminary experiments using DNA isolated from supernatants of a cell line with known major driver mutations. The role of cfDNA genotyping targeting mutations in KRAS and GNAS are currently under investigation in Japanese patients who have pancreatic tumors (UMIN000012810). We recruited 60 PDA and 140 IPMN patients with either benign or malignant disease. The primary endpoint of this multi-center prospective analysis is to evaluate whether such an approach can appropriately monitor the risk IPMN progression and detect localized early-stage PDA non-invasively. The major technical challenge of widespread implementation of this clinical test is the coverage for uncommon forms of KRAS mutation, as well as sensitivity for early stages cancer where the amount of cfDNA may be limited. The early results of these studies will be discussed.
F-028. Bcl-xL overexpression promotes Kras-mutated pancreatic ductal adenocarcinoma by inhibiting oncogene-induced senescence Kenji Ikezawa 1, Minoru Shigekawa 1, Hayato Hikita 1, Kiyoshi Iwahashi 1, Takuo Yamai 1, Tadashi Kegasawa 1, Takahiro Suda 1, Teppei Yoshioka 1, Ryotaro Sakamori 1, Tomohide Tatsumi 1, Hidetoshi Eguchi 2, Tetsuo Takehara 1 1 Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Japan 2 Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Japan
Background: Kras mutation is found in more than 90% of low-grade pancreatic intraepithelial lesions (PanIN-1) as well as PanIN-2/3 and PDAC. Bcl-xL, an anti-apoptotic Bcl-2 family protein, is also overexpressed in 90% of PDAC. However, it remains unclear how Bcl-xL impacts on tumor development. Methods: As a model of Kras-mutated pancreatic tumor, we used Pdx1Cre; LSL-KrasG12D (KP) mice. By crossing KP mice and Bcl-xL transgenic (Tg) mice, we generated KP Bcl-xL Tg mice. Results: In KP mice, Bcl-xL expression strongly enhanced in PanIN-2/3 and PDAC. In human resected specimens, Bcl-xL expression also increased with tumor progression. KP Bcl-xL Tg mice developed PDAC from 2 months (M) and died within 12M, while KP mice did not develop PDAC until 12M. These results indicate that Bcl-xL overexpression promotes carcinogenesis. To address the mechanism of rapid development, we examined senescence, which is known as tumor suppressive effects. Senescence was frequently detected in PanIN-1 of KP mice while it rarely found in PanIN-2/3 of KP mice or PanIN-1 of KP Bcl-xL Tg mice, where Bcl-xL strongly expressed. Together with in vitro finding that Bcl-xL knockdown toward PDAC cells increased senescent cells, Bcl-xL-regulated senescence was involved in the promotion of PDAC. Conclusion: Bcl-xL expression increases with tumor progression and Bcl-xL overexpression inhibits Kras-induced senescence leading to acceleration of PDAC. Anti-Bcl-xL agents might be a preventive therapy for PDAC.
adenocarcinoma (PDAC) patients and 6,111 controls in the context of the Pancreatic Disease Research (PANDoRA) consortium. We found that six SNPs showed a statistically significant association (p<0.05) with PDAC risk. In particular, rs3217992 was associated with an increased pancreatic cancer risk (ORhet¼1.14, 95% CI 1.01-1.27, p¼0.026, ORhom¼1.30, 95% CI 1.12-1.51, p¼4.9x10-4). This pleiotropic variant is reported to be a mir-SNP that, by changing the binding site of one or more miRNAs, could influence the normal cell cycle progression and in turn increase PDAC risk. In conclusion, we observed a novel association in a pleiotropic region that has been found to be of key relevance in the susceptibility to various types of cancer and diabetes.
F-026. Circulating tumor cluster is a prognostic marker in patients with pancreatic ductal adenocarcinoma Ming-Chu Chang 1, Ying-Chih Chang 2, Yung-Ming Jeng 3, Ching-Yao Yang 4, Yu-Wen Tien 4, Shih-Hung Yang 5, Eva Y.H.P. Lee 6, Wen-Hwa Lee 7, 8, Yu-Ting Chang 1 1 Department of Internal Medicine, National Taiwan University Hospital, Taiwan 2 Genomics Research Center, Academia Sinica, Taiwan 3 Department of Pathology, National Taiwan University Hospital, Taiwan 4 Department of Surgery, National Taiwan University Hospital, Taiwan 5 Department of Oncology, National Taiwan University Hospital, Taiwan 6 Department of Biological Chemistry, University of California, United States 7 Genomics Research Center, Academia Sinica, Taiwan 8 Graduate Institute of Clinical Medicine, China Medical University, China
Background: Characterization of circulating tumor cells has been used to provide prognostic, predictive and pharmacodynamic information in many different cancers. However, the clinical significance of circulating tumor cluster in patients with pancreatic ductal adenocarcinoma (PDAC) has yet to be determined. Methods: In this prospective study, circulating tumor cluster was enumerated in the peripheral blood of 63 patients with PDAC before treatment using anti-EpCAM-conjugated supported lipid bilayer coated microfluidic chips. Associations of circulating tumor cluster with patients' clinical factors and prognosis were determined. Results: Circulating tumor cluster was present in 81% (51 of 63) patients with mean±SD:29.7±1101.4. Circulating tumor cluster was an independent prognostic factor of overall survival and progression free survival (PFS). Patients were stratified into unfavorable and favorable circulating tumor cluster groups based on cluster numbers more or less than 30 per 2 ml blood respectively. Patients with baseline unfavorable cluster, when compared with patients with favorable cluster, had shorter PFS (2.7 vs. 12.1 months; P < 0.0001) and overall survival (6.4 vs. 19.8 months; P < 0.0001). Differences persisted if we stratified patients into early and advanced diseases. The number of cluster before treatment was an independent predictor of PFS and overall survival after adjustment for clinically significant factors. Conclusions: The number of circulating tumor cluster before treatment is an independent predictor of PFS and overall survival in patients with PDAC.
F-027. Plasma DNA genotyping using digital PCR: Novel diagnostic tool for early detection of pancreatic cancer Yusuke Mizukami 1, Yusuke Ono 1, Hidenori Karasaki 1, Kazuya Koizumi 2, Shingo Asahara 3, Kuniyuki Takahashi 4, Hiroyuki Maguchi 4 1 Center for Clinical and Biomedical Research, Sapporo Higashi Tokushukai Hospital, Japan 2 Center for Gastroenterology, Shonan Kamakura General Hospital, Japan
3 4
S53
Department of Gastroenterology, Chiba Tokushukai Hospital, Japan Center for Gastroenterology, Teine Keijinkai Hospital, Japan
The genetic alterations that are responsible for the initiation and progression of pancreatic ductal adenocarcinoma (PDA) could serve as a new generation of biomarkers for early diagnosis of the tumor. Recent technologies are emerging to allow genotyping of cell-free plasma DNA (cfDNA) shed from tumors into the general circulation. These tools offer the promise of sensitive and non-invasive methods for monitoring cancer genetics. There are two main types of pathologically and genetically distinct precursors for PDA, pancreatic intraepithelial neoplasias (PanINs) and intraductal papillary mucinous cystic neoplasias (IPMNs), and the key driver mutations in KRAS and/or GNAS regulate the diseases initiation and progression. We established protocols for super-sensitive and absolute quantification of very low concentrations of the target mutant alleles using a droplet digital PCR platform (Bio-Rad;QX200). Detection limit using specific primer/probe sets for each mutation were assessed to be 0.05% based on preliminary experiments using DNA isolated from supernatants of a cell line with known major driver mutations. The role of cfDNA genotyping targeting mutations in KRAS and GNAS are currently under investigation in Japanese patients who have pancreatic tumors (UMIN000012810). We recruited 60 PDA and 140 IPMN patients with either benign or malignant disease. The primary endpoint of this multi-center prospective analysis is to evaluate whether such an approach can appropriately monitor the risk IPMN progression and detect localized early-stage PDA non-invasively. The major technical challenge of widespread implementation of this clinical test is the coverage for uncommon forms of KRAS mutation, as well as sensitivity for early stages cancer where the amount of cfDNA may be limited. The early results of these studies will be discussed.
F-028. Bcl-xL overexpression promotes Kras-mutated pancreatic ductal adenocarcinoma by inhibiting oncogene-induced senescence Kenji Ikezawa 1, Minoru Shigekawa 1, Hayato Hikita 1, Kiyoshi Iwahashi 1, Takuo Yamai 1, Tadashi Kegasawa 1, Takahiro Suda 1, Teppei Yoshioka 1, Ryotaro Sakamori 1, Tomohide Tatsumi 1, Hidetoshi Eguchi 2, Tetsuo Takehara 1 1 Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Japan 2 Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Japan
Background: Kras mutation is found in more than 90% of low-grade pancreatic intraepithelial lesions (PanIN-1) as well as PanIN-2/3 and PDAC. Bcl-xL, an anti-apoptotic Bcl-2 family protein, is also overexpressed in 90% of PDAC. However, it remains unclear how Bcl-xL impacts on tumor development. Methods: As a model of Kras-mutated pancreatic tumor, we used Pdx1Cre; LSL-KrasG12D (KP) mice. By crossing KP mice and Bcl-xL transgenic (Tg) mice, we generated KP Bcl-xL Tg mice. Results: In KP mice, Bcl-xL expression strongly enhanced in PanIN-2/3 and PDAC. In human resected specimens, Bcl-xL expression also increased with tumor progression. KP Bcl-xL Tg mice developed PDAC from 2 months (M) and died within 12M, while KP mice did not develop PDAC until 12M. These results indicate that Bcl-xL overexpression promotes carcinogenesis. To address the mechanism of rapid development, we examined senescence, which is known as tumor suppressive effects. Senescence was frequently detected in PanIN-1 of KP mice while it rarely found in PanIN-2/3 of KP mice or PanIN-1 of KP Bcl-xL Tg mice, where Bcl-xL strongly expressed. Together with in vitro finding that Bcl-xL knockdown toward PDAC cells increased senescent cells, Bcl-xL-regulated senescence was involved in the promotion of PDAC. Conclusion: Bcl-xL expression increases with tumor progression and Bcl-xL overexpression inhibits Kras-induced senescence leading to acceleration of PDAC. Anti-Bcl-xL agents might be a preventive therapy for PDAC.