Shinichi Sakamoto

Prof. Dr. Shinichi Sakamoto

Urology, Chiba University, Chiba, Japan
orcid
Associate Professor Chiba University Graduate School of Medi...

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

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

Representative Publications

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12 April 2018 in International Journal of Urology
Verified
Journal Article
Open access
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Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
KMKatsuhito Miyazawa
Katsuhito Miyazawa
Takahiro YasuiTakahiro Yasui
Takahiro Yasui
TITaro Iguchi
Taro Iguchi
MFMisuzu Fujita
Misuzu Fujita
TITomohiko Ichikawa
Tomohiko Ichikawa
Objectives: To assess epidemiological and chronological trends of upper urinary tract stones in Japan in 2015.Methods: Patients with a first episode of upper urinary tract stones in 2015 were enrolled in this nationwide survey. The study included all hospitals approved by the Japanese Board of Urology, therefore covering most of the hospitals where urologists practice in Japan. The annual incidence and composition of urolithiasis were evaluated by age and sex. These results were compared with the previous results of the nationwide surveys from 1965 to 2005 to analyze temporal trends.Results: The estimated annual incidence of a first‐episode upper urinary tract stone in 2015 was 137.9 (191.9 in men and 86.9 in women) per 100 000. The estimated age‐standardized first‐episode upper urinary tract stone incidence in 2015 was 107.8 (150.6 in men and 63.3 in women) per 100 000, which did not represent a significant increase since 2005. An equivalent incidence was observed in patients aged >50 years, whereas a reduced incidence was observed in patients aged <50 years in both sexes. The proportion of patients who received percutaneous nephrolithotomy and/or ureteroscopy increased by approximately fivefold in the past 10 years.Conclusions: The steady increase in the annual incidence of upper urinary tract stones since 1955 leveled off in 2015. The current results show novel trends in the incidence and treatment modalities in the nationwide surveys of urolithiasis in Japan.

28 January 2020 in Scientific Reports
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MMMAIHULAN MAIMAITI
MAIHULAN MAIMAITI
Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
YYYasutaka Yamada
Yasutaka Yamada
MSMasahiro Sugiura
Masahiro Sugiura
JRJunryo Rii
Junryo Rii
TITomohiko Ichikawa
Tomohiko Ichikawa
L-type amino acid transporter 1 (LAT1) plays a role in transporting essential amino acids including leucine, which regulates the mTOR signaling pathway. Here, we studied the expression profile and functional role of LAT1 in bladder cancer. Furthermore, the pharmacological activity of JPH203, a specific inhibitor of LAT1, was studied in bladder cancer. LAT1 expression in bladder cancer cells was higher than that in normal cells. SiLAT1 and JPH203 suppressed cell proliferative and migratory and invasive abilities in bladder cancer cells. JPH203 inhibited leucine uptake by > 90%. RNA-seq analysis identified insulin-like growth factor-binding protein-5 (IGFBP-5) as a downstream target of JPH203. JPH203 inhibited phosphorylation of MAPK / Erk, AKT, p70S6K and 4EBP-1. Multivariate analysis revealed that high LAT1 expression was found as an independent prognostic factor for overall survival (HR3.46 P = 0.0204). Patients with high LAT1 and IGFBP-5 expression had significantly shorter overall survival periods than those with low expression (P = 0.0005). High LAT1 was related to the high Grade, pathological T stage, LDH, and NLR. Collectively, LAT1 significantly contributed to bladder cancer progression. Targeting LAT1 by JPH203 may represent a novel therapeutic option in bladder cancer treatment.

18 April 2023 in Scientific Reports
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SSShinpei Saito
Shinpei Saito
Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
KHKosuke Higuchi
Kosuke Higuchi
KSKodai Sato
Kodai Sato
XZXue Zhao
Xue Zhao
EKEiryo Kawakami
Eiryo Kawakami
Machine learning technology is expected to support diagnosis and prognosis prediction in medicine. We used machine learning to construct a new prognostic prediction model for prostate cancer patients based on longitudinal data obtained from age at diagnosis, peripheral blood and urine tests of 340 prostate cancer patients. Random survival forest (RSF) and survival tree were used for machine learning. In the time-series prognostic prediction model for metastatic prostate cancer patients, the RSF model showed better prediction accuracy than the conventional Cox proportional hazards model for almost all time periods of progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS). Based on the RSF model, we created a clinically applicable prognostic prediction model using survival trees for OS and CSS by combining the values of lactate dehydrogenase (LDH) before starting treatment and alkaline phosphatase (ALP) at 120 days after treatment. Machine learning provides useful information for predicting the prognosis of metastatic prostate cancer prior to treatment intervention by considering the nonlinear and combined impacts of multiple features. The addition of data after the start of treatment would allow for more precise prognostic risk assessment of patients and would be beneficial for subsequent treatment selection.

7 November 2020 in Cancer Science
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Journal Article
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Masaki ShiotaMasaki Shiota
Masaki Shiota
NTNaoki Terada
Naoki Terada
TSToshihiro Saito
Toshihiro Saito
AYAkira Yokomizo
Akira Yokomizo
NKNaoki Kohei
Naoki Kohei
J(Japanese Urological Oncology Group (JUOG)
Japanese Urological Oncology Group (JUOG)
Metastatic burden is a critical factor for therapy decision‐making in metastatic hormone‐sensitive prostate cancer. This study aimed to identify prognostic factors in men with high or low metastatic burden treated with primary androgen‐deprivation therapy. The study included 2450 men with de novo metastatic prostate cancer who were treated with primary androgen‐deprivation therapy at 30 institutions across Japan between 2008 and 2017. We investigated the prognostic value of various clinicopathological parameters for progression‐free survival (PFS) and overall survival (OS) in patients stratified by low or high metastatic burden. Among the 2450 men, 841 (34.3%) and 1609 (65.7 %) were classified as having low and high metastatic burden, respectively. The median PFS of the low‐ and high‐burden groups were 44.5 and 16.1 months, respectively, and the median OS was 103.2 and 62.7 months, ‐respectively. Percentage of biopsy positive core, biopsy Gleason grade group, T‐stage, and N‐stage were identified to be differentially prognostic. M1a was associated with worse PFS than was M1b in the low‐burden group, while lung metastasis was associated with better PFS and OS than was M1b in the high‐burden group. Differential prognostic factors were identified for patients with low‐ and high‐burden metastatic prostate cancer. These results may assist in decision‐making to select the optimal therapeutic strategies for patients with different metastatic burdens.

11 October 2018 in International Journal of Urology
Verified
Journal Article
Closed access
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Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
KMKatsuhito Miyazawa
Katsuhito Miyazawa
Takahiro YasuiTakahiro Yasui
Takahiro Yasui
TITaro Iguchi
Taro Iguchi
MFMisuzu Fujita
Misuzu Fujita
TITomohiko Ichikawa
Tomohiko Ichikawa

Verified
Journal Article
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TTTakaaki Tamura
Takaaki Tamura
YYYusuke Yoshioka
Yusuke Yoshioka
Shinichi SakamotoShinichi Sakamoto
Shinichi Sakamoto
TITomohiko Ichikawa
Tomohiko Ichikawa
TOTakahiro Ochiya
Takahiro Ochiya
Extracellular vesicles (EVs) are lipid membranous vesicles that are released from every type of cell. It has become clear that EVs are involved in a variety of biological phenomena, including cancer progression, and play critical roles in intracellular communication through the horizontal transfer of cellular cargoes such as proteins, DNA fragments, RNAs including mRNA and non-coding RNAs (microRNA, piRNA, and long non-coding RNA) and lipids. The most common cause of death associated with cancer is metastasis. Recent investigations have revealed that EVs are deeply associated with metastasis. Bone is a preferred site of metastasis, and bone metastasis is generally incurable and dramatically affects patient quality of life. Bone metastasis can cause devastating complications, including hypercalcemia, pathological fractures, spinal compression, and bone pain, which result in a poor prognosis. Although the mechanisms underlying bone metastasis have yet to be fully elucidated, increasing evidence suggests that EVs in the bone microenvironment significantly contribute to cancer progression and cancer bone tropism. Emerging evidence on EV functions in bone metastasis will facilitate the discovery of novel treatments. In this review, we will discuss the remarkable effects of EVs, especially on the tumor microenvironment in bone.