Shogen Boku

Dr. Shogen Boku

Kansai Medical University, Ōsaka, Japan

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 March 2016 in Cancer
Verified
Journal Article
Open access
PDF file
TNTomoki Nakamura
Tomoki Nakamura
AMAkihiko Matsumine
Akihiko Matsumine
AKAkira Kawai
Akira Kawai
NANobuhito Araki
Nobuhito Araki
TGTakahiro Goto
Takahiro Goto
TUTakafumi Ueda
Takafumi Ueda
BACKGROUND: Because the efficacy and safety of pazopanib in Japanese patients with soft tissue sarcoma (STS) had not been evaluated previously in a large‐scale cohort, the authors investigated the efficacy and safety of pazopanib in 156 Japanese patients with relapsed STS. This was a retrospective study based on the collection of real‐life, postmarketing surveillance data.METHODS: Patients received pazopanib with the objective of treating local recurrence (n = 20), metastasis (n = 104), and both (n = 32). The patient median age was 53.8 years. The primary objective of this study was to clarify the efficacy of pazopanib for patients with STS.RESULTS: The median treatment duration was 28.7 weeks, and the average dose intensity of pazopanib was 609 mg. Adverse events occurred in 127 patients (81.4%). In addition to the main common toxicities, such as hypertension and liver disorder, pneumothorax (n = 11) and thrombocytopenia (n = 16) also were observed. The median progression‐free survival for all patients was 15.4 weeks. The median progression‐free survival for patients with leiomyosarcoma, synovial sarcoma, undifferentiated pleomorphic sarcoma, and liposarcoma was 18.6 weeks, 16.4 weeks, 15.3 weeks, and 8 weeks, respectively. The median survival for all patients was 11.2 months. The median survival for patients with leiomyosarcoma, synovial sarcoma, undifferentiated pleomorphic sarcoma, and liposarcoma was 20.1 months, 10.6 months, 9.5 months, and 7.3 months, respectively.CONCLUSIONS: There were apparent differences in the efficacy of pazopanib treatment among histologic types of STS. Pazopanib treatment is a new treatment option; however, adverse events like pneumothorax and thrombocytopenia, which did not occur frequently in the PALETTE study (pazopanib for metastatic soft‐tissue sarcoma), should be taken into consideration. Cancer 2016;122:1408‐16. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

30 March 2020 in Cancers
Verified
Journal Article
Open access
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KMKeiko Miyamoto
Keiko Miyamoto
MWMotoki Watanabe
Motoki Watanabe
BSBoku Shogen
Boku Shogen
MSMamiko Sukeno
Mamiko Sukeno
MMMie Morita
Mie Morita
TSToshiyuki Sakai
Toshiyuki Sakai
As histone deacetylase inhibitors (HDACIs) have limited efficacy against solid tumors, we investigated whether and how oxidative stress is involved in sensitivity to HDACIs to develop a novel therapeutic option of HDACIs treatment. We first tested whether a reduction of the antioxidant glutathione (GSH) by glutamine deprivation affects sensitivity to a commercially available HDACI vorinostat and reactive oxygen species (ROS) accumulation. Next we investigated the relationship between a glutamate-cystine transporter xCT and the efficacy of vorinostat using siRNA of xCT and bioinformatic analyses. Finally, we verified the combinatory effects of vorinostat and the xCT inhibitor salazosulfapyridine (SASP) on ROS accumulation, cell death induction, and colony formation. Glutamine deprivation increased vorinostat-mediated cell death with ROS accumulation. Genetic ablation of xCT improved the efficacy of vorinostat, consistent with the results of public data analyses demonstrating that xCT expressions positively correlate with insensitivity to HDACIs in many types of cancer cell lines. Vorinostat caused ROS accumulation when combined with SASP, possibly resulting in synergistic ferroptosis. Our study provides a novel mechanistic insight into the mechanism underlying sensitivity to HDACIs involving xCT, suggesting xCT to be a promising predictive marker of HDACIs and rationalizing combinatory therapy of HDACIs with xCT inhibitors to induce ferroptosis.

16 July 2024 in Cancer Discovery
Verified
Journal Article
Open access
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THTadayoshi Hashimoto
Tadayoshi Hashimoto
YNYoshiaki Nakamura
Yoshiaki Nakamura
TFTakao Fujisawa
Takao Fujisawa
MIMitsuho Imai
Mitsuho Imai
TSTaro Shibuki
Taro Shibuki
TYTakayuki Yoshino
Takayuki Yoshino
The SCRUM-Japan MONSTAR-SCREEN consortium is a nationwide molecular profiling project employing artificial intelligence–driven multiomics analyses for patients with advanced malignancies, aiming to develop novel therapeutics and diagnostics and deliver effective drugs to patients. Concurrently, studies assessing molecular residual disease–based precision medicine for resectable solid tumors, including CIRCULATE-Japan, are ongoing. The substantial data generated by these platforms are stored within a state-of-the-art supercomputing infrastructure, VAPOR CONE. Since 2015, our project has registered over 24,000 patients as of December 2023. Among 16,144 patients with advanced solid tumors enrolled in MONSTAR-SCREEN projects, 5.0% have participated in matched clinical trials, demonstrating a 29.2% objective response rate and 14.8-month median survival (95% CI, 13.4–16.3) for patients treated in the matched clinical trials. Notably, patients who received matched therapy demonstrated significantly prolonged overall survival compared with those who did not (hazard ratio 0.77; 95% confidence interval, 0.71–0.83). Significance: Our nationwide molecular profiling initiative played pivotal roles in facilitating the enrollment of patients with advanced solid tumors into matched clinical trials and highlighted the substantial survival benefits of patients treated with matched therapy. We aim to facilitate an industry–academia data-sharing infrastructure ecosystem, fostering new drug discovery paradigms and precision medicine.

4 August 2022 in Cancer Immunology, Immunotherapy
Verified
Journal Article
Closed access
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TITatsuki Ikoma
Tatsuki Ikoma
MSMototsugu Shimokawa
Mototsugu Shimokawa
TMToshihiko Matsumoto
Toshihiko Matsumoto
BSBoku Shogen
Boku Shogen
TYTomoyo Yasuda
Tomoyo Yasuda
HSHironaga Satake
Hironaga Satake

7 March 2022 in Cancers
Verified
Journal Article
Open access
PDF file
TYTomohisa Yamamoto
Tomohisa Yamamoto
Sohei SatoiSohei Satoi
Sohei Satoi
SYSo Yamaki
So Yamaki
DHDaisuke Hashimoto
Daisuke Hashimoto
MIMitsuaki Ishida
Mitsuaki Ishida
MSMitsugu Sekimoto
Mitsugu Sekimoto
Background: Intraperitoneal chemotherapy using paclitaxel (i.p.-PTX) is expected to be a new therapeutic strategy for patients with pancreatic ductal adenocarcinoma (PDAC) and peritoneal dissemination. We evaluated the survival benefit of i.p.-PTX compared with standard systemic chemotherapy. Methods: Clinical data of 101 consecutive PDAC patients with peritoneal dissemination between 2007 and 2018 were analyzed. All patients were determined to have no other sites of distant organ metastasis to the lung, bone, or liver on contrast-enhanced CT imaging. Patients underwent staging laparoscopy or open laparotomy to confirm pathological evidence of peritoneal dissemination, and to exclude occult liver metastasis. Survival curves were estimated using the Kaplan–Meier method, and differences were compared using the log-rank test. Results: Forty-three patients were treated with i.p.-PTX (i.p.-PTX group) and forty-nine patients received standard systemic chemotherapy (Ctrl group). Nine patients did not receive any treatment (BSC group). The median survival time (MST) in the i.p.-PTX group was significantly longer than that in the Ctrl group (17.9 months vs. 10.2 months, p = 0.006). Negative peritoneal washing cytology was observed in 24 out of 43 patients in the i.p.-PTX group. The i.p.-PTX group tended to have a higher proportion of clinical responses than the Ctrl group (30% vs. 18%, p = 0.183). Conversion surgery was performed in 10 patients in the i.p.-PTX group and 2 patients in the Ctrl group after confirming disappearance of peritoneal dissemination with staging laparoscopy or open laparotomy (p = 0.005). The MST in patients who underwent surgical resection was significantly longer than that in patients who did not (27.4 months vs. 11.3 months; p < 0.0001). Conclusion: i.p.-PTX therapy provided improved survival in PDAC patients with peritoneal dissemination, and conversion surgery enhanced it in patients with favorable responses to chemotherapy. i.p.-PTX might become one of the treatment options to PDAC patients with peritoneal dissemination.

2 June 2025 in Cancer Science
Verified
Journal Article
Open access
THTadayoshi Hashimoto
Tadayoshi Hashimoto
NINaoko Iida
Naoko Iida
YNYoshiaki Nakamura
Yoshiaki Nakamura
NNNorio Nonomura
Norio Nonomura
CMChigusa Morizane
Chigusa Morizane
TYTakayuki Yoshino
Takayuki Yoshino
Claudin 18.2 (CLDN18.2), a tight junction protein isoform, is an emerging therapeutic target in oncology. CLDN18 is well‐characterized in gastric cancer, but its pan‐cancer expression profiles and isoform distributions are poorly documented. In the present study, we analyzed CLDN18 expression in patients with solid tumors enrolled in the MONSTAR‐SCREEN‐2 study using immunohistochemistry (IHC, n = 349) and whole‐transcriptome sequencing (WTS, n = 2191). A splice junction analysis algorithm characterized isoform distribution patterns in WTS data and evaluated temporal changes using paired pre‐ and postchemotherapy specimens. IHC detected CLDN18.2 (≥ 40% of tumor cells showing any staining intensity) in 16.3% of patients, with highest prevalence in gastric (54.5%), biliary tract (21.7%), pancreatic (20.7%), and small intestinal (18.2%) cancers. WTS and IHC findings were significantly correlated (p < 0.001). WTS analysis with optimized transcript thresholds (n = 2191) demonstrated the CLDN18‐high population to be 13.8%, with highest proportions in gastric (64.5%), small intestinal (40.0%), pancreatic (37.8%), and biliary tract (20.0%) cancers. Isoform analysis of 364 patients revealed CLDN18.2 predominance (mean 18.2/18.1 proportion 0.945), with CLDN18.1 predominance observed in only 4.9% of patients. Longitudinal analysis of 27 paired gastric cancer samples revealed a significant reduction in CLDN18 expression and a nonsignificant decrease in the CLDN18.2 proportion following chemotherapy. This analysis validates WTS as a complementary approach to IHC for CLDN18 assessment and demonstrates significant CLDN18 expression across multiple cancer types. The predominance of CLDN18.2 supports the expansion of targeted therapeutic approaches beyond gastric cancer and indicates the potential of RNA‐based screening.