研究者業績

今村 有佑

イマムラ ユウスケ  (Yusuke Imamura)

基本情報

所属
千葉大学 医学部附属病院 泌尿器科
学位
医学博士(2013年3月 千葉大学大学院)

J-GLOBAL ID
202201011577260098
researchmap会員ID
R000032224

論文

 199
  • Koichiro Kurokawa, Yasutaka Yamada, Shinichi Sakamoto, Takuro Horikoshi, Kodai Sato, Sakie Nanba, Yoshihiro Kubota, Manato Kanesaka, Ayumi Fujimoto, Nobuyoshi Takeuchi, Hiroki Shibata, Tomokazu Sazuka, Yusuke Imamura, Toyonori Tsuzuki, Takashi Uno, Tomohiko Ichikawa
    Scientific reports 14(1) 14868-14868 2024年6月27日  
    The prognostic significance of unconventional histology (UH) subtypes including intraductal carcinoma of the prostate (IDC-P), ductal adenocarcinoma, and cribriform pattern has been investigated for prostate cancer (PCa). However, little is known about magnetic resonance imaging (MRI) features and the oncological impact of tumor localization in localized PCa with UH. Clinical data of 211 patients with acinar adenocarcinoma (conventional histology [CH]) and 82 patients with UH who underwent robotic-assisted radical prostatectomy (RARP) were reviewed. Patients with UH are more likely to be older and have higher Gleason grade group, higher Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 score, and larger tumor volume (TV) than those with CH. Multivariate analysis identified the presence of UH as an independent prognostic factor for progression-free survival (PFS) (hazard ration (HR) 2.41, 95% confidence interval (CI) 0.22-0.79, P = 0.0073). No significant difference in PFS was seen regarding tumor localization (transition zone [TZ] or peripheral zone [PZ]) in patients with UH (P = 0.8949), whereas PZ cancer showed shorter PFS in patients with CH (P = 0.0174). PCa with UH was associated with higher progression than PCa with CH among resection margin (RM)-negative cases (P < 0.0001). Further, increased PI-RADS v2.1 score did not correlate with larger TV in UH (P = 0.991), whereas a significant difference in TV was observed in CH (P < 0.0001). The prognostic significance of UH tumor was independent of tumor localization, and shorter PFS was observed even in RM-negative cases, indicating an aggressive subtype with micro-metastatic potential. Furthermore, UH tumors are more likely to harbor a large TV despite PI-RADS v2.1 score ≤ 3. These findings will help optimal perioperative management for PCa with UH.
  • Yuki Murakami, Tomokazu Sazuka, Ryo Tsukamoto, Hiroaki Sato, Keisuke Ando, Manato Kanesaka, Yasutaka Yamada, Yusuke Imamura, Shinichi Sakamoto, Tomohiko Ichikawa
    Cureus 16(5) e61345 2024年5月  
    Non-muscle-invasive bladder carcinoma often occurs in older adults, who often also have urinary dysfunction. The residual urine volume is an important indicator of urinary dysfunction. However, the impact of the residual urine volume on intravesical recurrence remains unclear. In the present study, we analyzed the data of 372 patients at high or very high risk of cancer progression according to the Japanese Urological Association classification who had undergone transurethral resection of a bladder tumor. In univariate analysis, postoperative absence of intravesical Bacillus Calmette-Guérin (BCG) induction was an independent risk factor for intravesical recurrence (hazard ratio 1.94, absence versus presence, p = 0.0019). The incidence of intravesical recurrence did not significantly differ between the mild, intermediate, and severe residual urine groups in the total cohort. Among the BCG-treated cohort, the three groups showed similar trends. Among the non-BCG-treated cohort, although the patients with more than 100 ml of residual urine tended to have more intravesical recurrence than patients with a smaller residual urine volume, this difference did not reach statistical significance. BCG treatment is recommended for patients at high risk of bladder carcinoma. Patients with a large residual urine volume without BCG treatment may be at high risk of intravesical recurrence.
  • Shinpei Saito, Keisuke Ando, Shinichi Sakamoto, Minhui Xu, Yasutaka Yamada, Junryo Rii, Sanji Kanaoka, Jiaxing Wei, Xue Zhao, Sangjon Pae, Manato Kanesaka, Yusuke Goto, Tomokazu Sazuka, Yusuke Imamura, Yoshie Reien, Norie Hamaguchi-Suzuki, Shota Saito, Yuri Hirayama, Hirofumi Hashimoto, Yoshikatsu Kanai, Tomohiko Ichikawa, Naohiko Anzai
    Cancer science 2024年4月24日  
    L-type amino acid transporter 1 (LAT1) is specifically expressed in many malignancies, contributes to the transport of essential amino acids, such as leucine, and regulates the mammalian target of rapamycin (mTOR) signaling pathway. We investigated the expression profile and functional role of LAT1 in prostate cancer using JPH203, a specific inhibitor of LAT1. LAT1 was highly expressed in castration-resistant prostate cancer (CRPC) cells, including C4-2 and PC-3 cells, but its expression level was low in castration-sensitive LNCaP cells. JPH203 significantly inhibited [14C] leucine uptake in CRPC cells but had no effect in LNCaP cells. JPH203 inhibited the proliferation, migration, and invasion of CRPC cells but not of LNCaP cells. In C4-2 cells, Cluster of differentiation (CD) 24 was identified by RNA sequencing as a novel downstream target of JPH203. CD24 was downregulated in a JPH203 concentration-dependent manner and suppressed activation of the Wnt/β-catenin signaling pathway. Furthermore, an in vivo study showed that JPH203 inhibited the proliferation of C4-2 cells in a castration environment. The results of this study indicate that JPH203 may exert its antitumor effect in CRPC cells via mTOR and CD24.
  • Sanji Kanaoka, Atsushi Okabe, Manato Kanesaka, Bahityar Rahmutulla, Masaki Fukuyo, Motoaki Seki, Takayuki Hoshii, Hiroaki Sato, Yusuke Imamura, Shinichi Sakamoto, Tomohiko Ichikawa, Atsushi Kaneda
    Cancer Letters 588 216815-216815 2024年4月  
  • Shuhei Kamada, Shinichi Sakamoto, Ryo Kinoshita, Xue Zhao, Tomohiko Kamasako, Ryosuke Yamase, Rii Junryo, Shinpei Saito, Pae Sangjon, Akinori Takei, Yasutaka Yamada, Yusuke Goto, Yusuke Imamura, Taro Iguchi, Atsushi Mizokami, Hiroyoshi Suzuki, Koichiro Akakura, Tomohiko Ichikawa
    The Prostate 2024年2月27日  
    BACKGROUND: To clarify the clinical roles of changes in testosterone (T) levels with a cut-off level of 20 ng/dL as predictive factors for prostate cancer patients treated with degarelix acetate. METHODS: A total of 120 prostate cancer patients who received hormone therapies with gonadotropin-releasing hormone antagonist degarelix acetate were retrospectively analyzed. The predictive values of nadir T levels, max T levels, T bounce, and other clinical factors were evaluated for overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS). T bounce was defined as satisfying both nadir serum T levels of <20 ng/dL and max serum T levels of ≥20 ng/dL during hormone therapies. RESULTS: In 120 prostate cancer patients, 16 (13%) patients did not achieve nadir T < 20 ng/dL, and 76 (63%) patients had max T ≥ 20 ng/dL. The median times to nadir T and max T are 108 and 312 days, respectively. T bounce was shown in 60 (50%) patients and is associated with favorable prognoses both for OS (p = 0.0019) and CSS (p = 0.0013) but not for PFS (p = 0.92). While in the subgroup analyses of the patients with the progression of the first-line hormone therapies, T bounce predicts favorable OS (p = 0.0015) and CSS (p = 0.0013) after biochemical recurrence. CONCLUSIONS: The present study revealed that T bounce with cut-off levels of 20 ng/dL is a promising biomarker that predicts OS and CSS for prostate cancer patients treated with degarelix acetate.

MISC

 97

共同研究・競争的資金等の研究課題

 5