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The epithelial-mesenchymal transition (EMT), a normal biological process by which epithelial cells acquire a mesenchymal phenotype, is associated with migration, metastasis, and chemoresistance in cancer cells, and with poor prognosis in patients with esophageal cancer. However, therapeutic strategies to inhibit EMT in tumor environments remain elusive. Here, we show the therapeutic potential of telomerase-specific replication- competent oncolytic adenovirus OBP-301 in human esophageal cancer TE4 and TE6 cells with an EMT phenotype. Transforming growth factor-β (TGF-β) administration induced the EMT phenotype with spindleshaped morphology, upregulation of mesenchymal markers and EMT transcription factors, migration, and chemoresistance in TE4 and TE6 cells. OBP-301 significantly inhibited the EMT phenotype via E1 accumulation. EMT cancer cells were susceptible to OBP-301 via massive autophagy induction. OBP-301 suppressed tumor growth and lymph node metastasis of TE4 cells co-inoculated with TGF-β-secreting fibroblasts. Our results suggest that OBP-301 inhibits the TGF-β-induced EMT phenotype in human esophageal cancer cells. OBP-301-mediated E1A overexpression is a promising antitumor strategy to inhibit EMT-mediated esophageal cancer progression.

Purpose: We developed a new technique to fold a neobladder (NB) simply by using a modified Vesica Ileale Padovana (VIP) with a hybrid approach. We provide a step-by-step description of our technique as it was used in this initial experience. Methods: A total of 10 male patients with a median age of 66 years underwent robot-assisted radical cystectomy (RARC) with an orthotopic NB via a hybrid approach from March 2022 to February 2023. After the isolation of the bladder and bilateral pelvic lymphadenectomy, Wallace plate creation was performed, and the robot was undocked. We extracorporeally performed the removal of the specimen and a side-to-side ileoileal anastomosis, and then the VIP NB posterior plate was rotated 90 degrees counterclockwise using a 45 cm detubularized ileum. The robot was redocked; then, circumferential urethra–ileal anastomosis, side-to-middle anterior wall closure, and ureteric afferent limb anastomosis were performed. Results: The median estimated blood loss was 524 mL, and the mean operative time was 496 min. Patients had a high continence rate, and no high-grade complications were observed. Conclusion: The NB configuration using the modified VIP method for a hybrid approach is a feasible surgical technique to minimize the movement of robotic forceps. In particular, it may be more useful in Asian individuals with narrow pelvises.

Neuroblastoma (NB) is a primary malignant tumor of the peripheral sympathetic nervous system. High-risk NB is characterized by MYCN amplification and human telomerase reverse transcriptase (hTERT) rearrangement, contributing to hTERT activation and a poor outcome. For targeting hTERT-activated tumors, we developed two oncolytic adenoviruses, OBP-301 and tumor suppressor p53-armed OBP-702, in which the hTERT promoter drives expression of the viral E1 gene for tumor-specific virus replication. In this study, we demonstrate the therapeutic potential of the hTERT-driven oncolytic adenoviruses OBP-301 and OBP-702 using four human MYCN-amplified NB cell lines (IMR-32, CHP-134, NB-1, LA-N-5) exhibiting high hTERT expression. OBP-301 and OBP-702 exhibited a strong antitumor effect in association with autophagy in NB cells. Virus-mediated activation of E2F1 protein suppressed MYCN expression. OBP-301 and OBP-702 significantly suppressed the growth of subcutaneous CHP-134 tumors. Thus, these hTERT-driven oncolytic adenoviruses are promising antitumor agents for eliminating MYCN-amplified NB cells via E2F1-mediated suppression of MYCN protein., Graphical Abstract, MYCN-amplified neuroblastoma (NB) cells exhibit transcriptional activation of human telomerase reverse transcriptase (hTERT) expression. hTERT promoter-driven oncolytic adenoviruses OBP-301 and OBP-702 exhibited a strong antitumor effect in human MYCN-amplified NB cells via induction of autophagy and E2F1-mediated MYCN suppression.

Pancreatic ductal adenocarcinoma (PDAC) cells have an exceptional ability to invade nerves through pronounced crosstalk between nerves and cancer cells; however, the mechanism of PDAC cell invasion remains to be elucidated. Here, we demonstrate the therapeutic potential of telomerase-specific oncolytic adenoviruses, OBP-301 and tumor suppressor p53-armed OBP-702, against human PDAC cells. Highly invasive PDAC cells exhibited higher levels of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) expression independent of KRAS expression; ERK1/2 inhibitor or small interfering RNA (siRNA) treatment significantly reduced the migration and invasion of PDAC cells, suggesting that the ERK signaling pathway is associated with the invasiveness of PDAC cells. OBP-702 infection suppressed ERK signaling and inhibited PDAC cell migration and invasion more efficiently than OBP-301. OBP-702 also effectively inhibited PDAC cell invasion even when invasiveness was enhanced by administration of motility stimulators, such as nerve and neurosecretory factors. Moreover, noninvasive whole-body imaging analyses showed that OBP-702 significantly suppressed tumor growth in an orthotopic PDAC xenograft model, although both viruses were equally effective against subcutaneous tumors, suggesting that OBP-702 can influence the orthotopic tumor microenvironment. Our data suggest that oncolytic virus-mediated disruption of ERK signaling is a promising antitumor strategy for attenuating the invasiveness of PDAC cells., Graphical Abstract, Telomerase-specific oncolytic adenovirus OBP-702 armed with the wild-type p53 tumor suppressor suppressed ERK signaling and inhibited pancreatic ductal adenocarcinoma (PDAC) cell migration and invasion, even when enhanced by nerve-derived motility stimulators. OBP-702 also significantly suppressed tumor growth in an orthotopic PDAC xenograft model by influencing the tumor microenvironment.

Background The peritoneum is one of the most frequent metastatic sites in pancreatic cancer patients, and peritoneal dissemination makes this disease refractory due to aggressive progression and chemoresistance. Although the role of the tumor microenvironment in cancer development is recognized, the correlation between the peritoneal environment and refractoriness of peritoneal dissemination remains unclear. The intraperitoneal tumor-microenvironment and its potential role in the progression of peritoneal dissemination and chemo-refractoriness, focusing especially on macrophages, were investigated. Materials and methods Peritoneal washes were obtained from pancreatic cancer patients, and cellular components were subjected to immunofluorescence assays. The effects of macrophages induced from monocytic THP-1 cells on pancreatic cancer cells were examined in co-culture conditions. The in vivo effects of macrophages on tumor growth and chemo-sensitivity were investigated by subcutaneously or intraperitoneally co-injecting cancer cells with macrophages into mice. Results CD204-positive macrophages were present along with cancer cells in the peritoneal washes. In in vitro co-culture, tumor-associated macrophages affected pancreatic cancer cells, induced the epithelial-to-mesenchymal transition (EMT), and made them more resistant to chemotherapeutic agents. M2 macrophages promoted growth of both subcutaneous tumors and peritoneal dissemination in mice. Furthermore, co-inoculation of M2 macrophages conferred chemoresistance in the peritoneal dissemination mouse model, which significantly shortened their survival. Conclusion Intraperitoneal tumor-associated macrophages potentially play an important role in promotion of peritoneal dissemination and chemoresistance of pancreatic cancer via EMT induction. Electronic supplementary material The online version of this article (10.1186/s13046-018-0981-2) contains supplementary material, which is available to authorized users.

Epithelial-mesenchymal transition (EMT) is a biological process by which epithelial cells acquire mesenchymal characteristics. In malignant tumors, EMT is crucial for acquisition of a mesenchymal phenotype with invasive and metastatic properties, leading to tumor progression. An inflammatory microenvironment is thought to be responsible for the development and progression of colorectal cancer (CRC); however, the precise role of inflammatory microenvironments in EMT-related CRC progression remains unclear. Here, we show the spatiotemporal visualization of CRC cells undergoing EMT using a fluorescence-guided EMT imaging system in which the mesenchymal vimentin promoter drives red fluorescent protein (RFP) expression. An inflammatory microenvironment including TNF-α, IL-1β, and cytokine-secreting inflammatory macrophages induced RFP expression in association with the EMT phenotype in CRC cells. In vivo experiments further demonstrated the distribution of RFP-positive CRC cells in rectal and metastatic tumors. Our data suggest that the EMT imaging system described here is a powerful tool for monitoring EMT in inflammatory microenvironment–CRC networks.

Objectives To evaluate the clinical benefit of adjuvant platinum-based chemotherapy after radical cystectomy for muscle-invasive bladder cancer in routine clinical practice. Methods The present observational study was carried out to compare the effectiveness of adjuvant chemotherapy versus observation post-radical cystectomy in patients with clinically muscle-invasive bladder cancer. Cancer-specific survival and overall survival between the adjuvant chemotherapy group and radical cystectomy alone group were compared using Kaplan–Meier method and log–rank test. After adjusting for background factors using propensity score weighting, differences in cancer-specific survival and overall survival between these two groups were compared. Subgroup analyses by the pathological characteristics were carried out. Results In total, 322 patients were included in the present study. Of these, 23% received adjuvant chemotherapy post-radical cystectomy. Clinicopathological characteristics showed that patients in the adjuvant chemotherapy group were pathologically more advanced and were at higher risk than the radical cystectomy alone group. In the unadjusted population, although it is not significant, the adjuvant chemotherapy group had lower overall survival (3-year overall survival; 61.5% vs 73.6%, HR 1.33, P = 0.243, log–rank test, adjuvant chemotherapy vs radical cystectomy alone). In the weighted propensity score analysis, although it is not significant, the adjuvant chemotherapy group were superior to radical cystectomy alone groups (overall survival: HR 0.65, 95% CI 0.39–1.09, P = 0.099, log–rank test, adjuvant chemotherapy vs radical cystectomy alone). Subgroup analyses showed that adjuvant chemotherapy significantly reduced the hazard ratio of overall survival and cancer-specific survival in the ≥pT3, pN+, ly+ and v+ subgroups. Conclusions Platinum-based adjuvant chemotherapy might be associated with increased cancer-specific survival and overall survival in patients with high-risk invasive bladder cancer.

Background Some risk classifications to determine prognosis of patients with non-muscle invasive bladder cancer (NMIBC) have disadvantages in the clinical setting. We investigated whether the EORTC (European Organization for Research and Treatment of Cancer) risk stratification is useful to predict recurrence and progression in Japanese patients with NMIBC. In addition, we developed and validated a novel, and simple risk classification of recurrence. Methods The analysis was based on 1085 patients with NMIBC at six hospitals. Excluding recurrent cases, we included 856 patients with initial NMIBC for the analysis. The Kaplan–Meier method with the log-rank test were used to calculate recurrence-free survival (RFS) rate and progression-free survival (PFS) rate according to the EORTC risk classifications. We developed a novel risk classification system for recurrence in NMIBC patients using the independent recurrence prognostic factors based on Cox proportional hazards regression analysis. External validation was done on an external data set of 641 patients from Kyorin University Hospital. Findings There were no significant differences in RFS and PFS rates between the groups according to EORTC risk classification. We constructed a novel risk model predicting recurrence that classified patients into three groups using four independent prognostic factors to predict tumour recurrence based on Cox proportional hazards regression analysis. According to the novel recurrence risk classification, there was a significant difference in 5-year RFS rate between the low (68.4%), intermediate (45.8%) and high (33.7%) risk groups (P, Highlights • There were no significant differences in RFS & PFS rates between EORTC risk groups. • We constructed a novel recurrence risk classification using four clinical factors. • There was a significant difference in RFS rate between the novel risk groups. Risk classification is essential in any medical treatment. It is constructed based on the large data of observed events such as recurrence and death. However different race/ethnic groups may not follow the prediction since genetic and environmental factors affect the events. Bladder cancer is a frequent cancer among men. We evaluated the commonly-used European risk classification of non-muscle invasive bladder cancer. Surprisingly, this risk classification did not segregate the Japanese patients well. In this study we developed and validated a novel risk model predicting recurrence. This risk classification will be useful among Asian patiens with non-muscle invasive bladder cancer.

Background: Epithelial-mesenchymal transition (EMT) is known to be one of the poor prognostic factors. EMT is a biological process, by which epithelial cancer cells lose their epithelial characteristics and gain mesenchymal properties, including invasion, metastasis and drug resistance, resulting in tumor recurrence and poor prognosis. Esophageal cancer is one of the most common cause of cancer-related death worldwide, especially in East Asia. Despite the recent advances in the treatment of esophageal cancer, antitumor therapy to inhibit EMT program remains to be developed. We developed a telomerase-specific replication-selective oncolytic adenovirus (OBP-301; Telomelysin), in which the human telomerase reverse transcriptase promoter drives the expression of E1A and E1B for virus replication. In this study, we explored the biological effect of OBP-301 on EMT in human esophageal cancer cells. Methods: Transforming growth factor-β (TGF-β) was used to induce EMT in human esophageal cancer TE-4 cells. To investigate whether OBP-301 infection affects TGF-β-induced EMT, we performed western blot and real-time PCR analysis for EMT-related markers. We also examined the migration capability using transwell migration assay. In vitro antitumor effect of OBP-301 and chemotherapeutic agents on TGF-β-treated TE-4 cells were assessed by a XTT assay. Results: Administration of TGF-β induced mesenchymal characteristics, including spindle-shaped morphology, increased migration capability, and upregulation of mesenchymal markers N-cadherin and vimentin, in TE-4 cells. When TGF-β-treated TE-4 cells were infected with OBP-301, upregulation of N-cadherin and vimentin expression was attenuated. Upregulation of EMT-transcription factors, Snail, Slug, and ZEB1 by TGF-β was reduced by OBP-301 infection. OBP-301 also inhibited TGF-β-induced enhancement of migration capability. Moreover, interestingly, EMT-induced TE-4 cells acquired chemoresistance, whereas they were sensitive to OBP-301-mediated lytic effect. Conclusion: Our data suggest that telomerase-specific oncolytic virotherapy is a promising antitumor strategy to inhibit TGF-β-induced EMT and warrants clinical trials in human esophageal cancer. Currently, we are conducting a phase I/II clinical study of OBP-301 in combination with radiotherapy for esophageal cancer. Citation Format: Tomoya Masuda, Hiroshi Tazawa, Takeshi Ieda, Yuuri Hashimoto, Shunsuke Tanabe, Kazuhiro Noma, Yasuo Urata, Shunsuke Kagawa, Yasuhiro Shirakawa, Toshiyoshi Fujiwara. Transforming growth factor-b-induced epithelial-mesenchymal transition is attenuated by telomerase-specific oncolytic virotherapy in human esophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2033.

Background: Epithelial-mesenchymal transition (EMT) is a biologic process by which epithelial cancer cells acquire mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancer (CRC). However, the precise role of inflammatory microenvironment in the EMT-related tumor progression remains unclear because EMT network is regulated by complex crosstalk between tumor and normal cells. In this study, we developed a fluorescence-guided live-cell imaging system for the spatiotemporal visualization of EMT state, and assessed the in vitro and in vivo visualization of EMT state in human CRC cells under the inflammatory microenvironment. Methods: We used two human CRC cell lines, HCT116 and RKO. The promoter of mesenchymal marker vimentin was used for inducing the EMT-dependent red fluorescence protein (RFP) expression in human CRC cells. The RFP expression was quantitatively analyzed to evaluate its association with EMT-related markers and malignant phenotype. Inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or co-culture with inflammatory mouse macrophage cell line RAW264.7 stimulated by lipopolysaccharide (LPS) (200 ng/mL) were used as an inflammatory microenvironment. Biodistribution of EMT cells was analyzed using in vivo experiments with primary and metastatic CRC xenograft tumors. Results: Inflammatory cytokines reversely induced the RFP expression in association with EMT-related malignant phenotype, such as morphologic change, EMT marker modulation, and invasion ability, in HCT116 and RKO cells. Co-culture with LPS-stimulated inflammatory macrophages also induced the RFP expression by secreting inflammatory cytokines. In vivo experiments revealed that EMT cells were detected within tumor tissues at colon, liver and peritoneum. Conclusions: Our results suggest that inflammatory microenvironment has a great potential to induce EMT program in CRC cells. This fluorescence-guided EMT imaging system is a useful tool for monitoring the EMT state in the inflammation microenvironment-CRC network in vitro and in vivo. Citation Format: Hiroshi Tazawa, Takeshi Ieda, Shuya Yano, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Masahiko Nishizaki, Shunsuke Kagawa, Takashi Saitou, Takeshi Imamura, Toshiyoshi Fujiwara. Visualization of epithelial-mesenchymal transition in inflammatory microenvironment-colorectal cancer network in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1101.

Background: Epithelial-mesenchymal transition (EMT) is a biological process, by which epithelial cancer cells acquire mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancer. However, the role of inflammatory microenvironment in the EMT-related tumor progression remains unclear. To explore the relationship between inflammatory microenvironment and EMT, a live imaging system for EMT is a promising strategy on the in vitro and in vivo experiments. In this study, we developed a fluorescence-guided live cell imaging system for the assessment of spatiotemporal dynamics of EMT, and investigated the potential of inflammatory microenvironment for the induction of EMT phenotype in human colorectal cancer. Methods: Two human colorectal cancer cell lines, HCT116 and RKO, were stably transfected with vimentin promoter-driven red fluorescence protein TurboFP635 expression vector. Both cell lines were treated with inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or co-cultured with mouse macrophage cell line RAW264.7 in the presence of lipopolysaccharide (LPS) (200 ng/ml). The time-lapse live imaging was observed by confocal laser scanning microscope. Migration and invasion properties were examined by transwell chamber assays. The fluorescence intensity was measured by microplate reader and flow cytometric analysis. The expression of EMT-related markers was assessed by Western blot analysis and q-PCR. EMT-induced HCT116 and RKO cells were treated with anti-inflammatory agents, aspirin (1mM) and salicylic acid (1 mM), for the suppression of EMT. Results: Inflammatory cytokines (IL-1β and TNF-α) induced red fluorescence intensity and morphological change like mesenchymal phenotype in HCT116 and RKO cells. Removal of inflammatory cytokines attenuated red fluorescence intensity and morphological change in both cells. Inflammatory cytokines also induced the migration and invasion properties in association with EMT-related markers. Moreover, co-culture with LPS-stimulated inflammatory macrophages also induced red fluorescence intensity and morphological change as well as inflammatory cytokines. Anti-inflammatory agents significantly suppressed the fluorescence-related EMT phenotype under inflammatory microenvironment. Conclusions: These results suggest that inflammatory microenvironment has a great potential for the induction of EMT process during colorectal cancer progression. This unique fluorescence-guided EMT imaging system is useful method for the exploration of inflammation-mediated tumor progression. Citation Format: Takeshi Ieda, Hiroshi Tazawa, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Takeshi Nagasaka, Masahiko Nishizaki, Shunsuke Kagawa, Takeshi Imamura, Toshiyoshi Fujiwara. Fluorescence-guided spatiotemporal dynamics of epithelial-mesenchymal transition under inflammatory microenvironment during colorectal cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5809. doi:10.1158/1538-7445.AM2017-5809

392 Background: The clinical evidence of adjuvant chemotherapy (AC ) is less robust than neoadjuvant chemotherapy (NAC). However, several surveys suggest that urologists prefer to use AC more frequently than NAC. We evaluate the clinical benefit of adjuvant platinum based chemotherapy following radical cystectomy (RC) for muscle-invasive bladder cancer (BCa) in routine clinical practice. Methods: This observational study was conducted to compare the effectiveness of AC versus observation postcystectomy in patients with clinicallymuscle-invasive BCa. Cancer-specific survival (CSS) and overall survival (OS) between the AC group and RC alone group were compared using Kaplan-Meiyer method and log-rank test. After adjusting for background factors using propensity score weighting, differences in CSS and OS between these two groups were compared. Subgroup analyses by the pathological characteristics were performed. Results: In total, 322 patients were included in this study. Of these, 23% received AC postcystectomy. Clinicopathological characteristics showed that patients in the AC group were pathologically more advanced and were at higher risk than the RC alone group. In the unadjusted population, although it is not significantly, the AC group had lower overall survival (3-years OS; 61.5% vs 73.6%, HR 1.44, p = 0.243, log-rank test, AC vs RC alone). In the weighted propensity score analysis, although it is not significantly, AC group were superior than RC alone groups (OS: HR 0.65, 95%CI 0.39-1.09, p = 0.099, log-rank test, AC vs RC alone). Subgroup analyses showed that AC significantly reduced the hazard ratio of OS and CSS in ≥ pT3, pN+, ly+, and v+ subgroups. Conclusions: The weighted propensity score analyses showed that platinum-based AC might be associated with increased CSS and OS in patients with high-risk invasive BCa.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the worst prognosis disease with an overall 5-year survival rate of less than 5%. More than 80% of patients are not eligible for curative surgical resection due to extensive local tumor invasion and early systemic metastasis at the time of diagnosis. Moreover, even after curative surgery, PDAC patients still have poor prognosis due to local recurrence and systemic metastasis. Although activation of oncogenic KRAS is implicated in the initiation, promotion and progression of pancreatic cancer, the development of cancer treatment targeting KRAS remains unsuccessful. Moreover, tumor suppressor p53 is also frequently inactivated in PDAC patients. We recently developed two types of tumor-specific replication-competent oncolytic adenoviruses, OBP-301 and OBP-702, which is modified OBP-301 to express tumor suppressor p53 protein. In this study, we investigated whether oncolytic adenoviruses inhibit cell viability, migration, invasion and KRAS-driven signaling pathway in PDAC cells. Methods: We used 4 PDAC cells (MIA PaCa-2, Capan-1, Panc-1, BxPC-3). The cell viability was examined by XTT assay. Migration and invasion properties were assessed using transwell chamber assay. The modulation of KRAS-driven signaling pathway was investigated by Western blot analysis. Results: OBP-301 induced moderate antitumor effect in MIA Paca-2, Capan-1 and BxPC-3 cells and strong antitumor effect in Panc-1 cells in a dose-dependent manner, whereas OBP-702 induced profound antitumor effect in all human PDAC cells, suggesting the broad spectrum of OBP-702's efficacy. OBP-301 induced autophagy-related cell death, whereas OBP-702 induced autophagy- and apoptosis-related cell deaths. In migration and invasion assays, MIA Paca-2 and Capan-1 cells were low-invasive type, and Panc-1 and BxPC-3 cells were high-invasive type. OBP-301 and OBP-702 inhibited migration and invasion properties of high-invasive type PDAC cells, and the inhibitory effect of OBP-702 was stronger than that of OBP-301. We also found that oncolytic adenoviruses inhibited the expression of KRAS and KRAS-downstream target MEK/ERK proteins in high-invasive type PDAC cells. Conclusions: Our results suggest that oncolytic adenoviruses, OBP-301 and OBP-702, inhibit the survival and invasive phenotype of pancreatic cancer by suppressing KRAS-driven signaling pathway and reactivating p53-driven signaling pathway. In vivo experiments are under way to investigate the anti-tumor and anti-invasive effects of oncolytic adenoviruses using BxPC-3 xenograft tumors. The clinical trial of intratumoral administration of oncolytic adenoviruses in patients with invasive PDAC should be also warranted. Citation Format: Takeshi Koujima, Hiroshi Tazawa, Takeshi Ieda, Kazuya Kuwada, Terutaka Tanimoto, Shinji Kuroda, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Virally enhanced p53 reactivation impairs KRAS-driven pancreatic cancer invasion. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3748.

Background: Epithelial-mesenchymal transition (EMT) is a biological process, by which epithelial cancer cells acquire the mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. However, as EMT is a reversible process and depends on tumor microenvironment, the precise role of EMT in cancer progression remains unclear. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancers. To evaluate the implication of EMT in the inflammation-mediated colorectal cancer progression, a live imaging system for EMT is needed on the in vitro and in vivo experiments. In this study, we generated the EMT-detectable colorectal cancer cells by introducing mesenchymal cell marker promoter-driven fluorescence protein expression vector, and investigated whether inflammation-induced EMT is detectable in vitro. Methods: To generate the EMT-detectable colorectal cancer cells HCT116-VIM635, human colorectal cancer cell line HCT116 was stably transfected with vimentin promoter-driven red fluorescence protein TurboFP635 expression vector. EMT was induced in HCT116-VIM635 cells by treatment with inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or by co-culture with mouse macrophage cell line RAW264.7 in the presence of lipopolysaccharide (LPS) (200 ng/ml). The time-lapse live imaging was observed by confocal laser scanning microscope. Migration and invasion properties were examined by transwell chamber assays. The fluorescence intensity was measured by microplate reader and flow cytometric analysis. The expression of EMT-related markers was assessed by Western blot analysis. Results: Administration of IL-1β or TNF-α induced the TurboFP635 expression in consistent with morphological change like mesenchymal phenotype in HCT116-VIM635 cells. Removal of these inflammatory cytokines attenuated the TurboFP635 expression and morphological change in HCT116-VIM635 cells, suggesting the detection of reverse EMT process in these cells. Inflammatory cytokines also induced the migration and invasion properties and the expression of EMT-related markers in HCT116-VIM635 cells. Moreover, co-culture with RAW264.7 cells stimulated with LPS also induced the TurboFP635 expression and morphological change as well as inflammatory cytokines in HCT116-VIM635 cells. Conclusions: Our results suggest that this unique live imaging system for EMT has a great potential to detect reversible EMT process during inflammation-induced cancer progression. This system would be useful strategy to assess the role of EMT during inflammation-mediated cancer progression in vivo. Citation Format: Takeshi Ieda, Hiroshi Tazawa, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Takeshi Nagasaka, Masahiko Nishizaki, Shunsuke Kagawa, Toshiyoshi Fujiwara. A novel live imaging system for inflammation-induced epithelial-mesenchymal transition in colorectal cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1613.