Updated on 2024/03/22

写真a

 
NISHII Ryuichi
 
Organization
Graduate School of Medicine Professor
Graduate School
Graduate School of Medicine
Undergraduate School
School of Health Sciences
Title
Professor
External link

Degree 1

  1. Doctor (Medicine) ( 2000.3   Miyazaki Medical College ) 

Research Areas 1

  1. Life Science / Radiological sciences

 

Papers 4

  1. Synthesis and evaluation of a rociletinib analog as prospective imaging double mutation L858R/T790M in non-small cell lung cancer

    Fawwaz, M; Mishiro, K; Purwono, B; Nishii, R; Ogawa, K

    JOURNAL OF PHARMACY & PHARMACOGNOSY RESEARCH   Vol. 12 ( 2 ) page: 231 - 242   2024.3

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    Publisher:Journal of Pharmacy and Pharmacognosy Research  

    Context: Imaging the mutation status of non-small cell lung cancer (NSCLC) using radiolabeled tyrosine kinase inhibitor (TKI) analogs has garnered interest due to their unique interactions with the target epidermal growth factor receptor (EGFR). Rociletinib is a third-generation TKI that selectively inhibits the activated EGFR L858R/T790M mutations while sparing the wild-type EGFR. Aims: To synthesize a rociletinib analog for radioiodination purposes and evaluate its affinity for EGFR L858R/T790M using molecular docking and in vitro cytotoxicity assay. Methods: The rociletinib analog, N-{3-[(4-{[4-(4-acetylpiperazin-1-yl)-2-methoxyphenyl]amino}-5-(trifluoromethyl)pyrimidine-2-yl)amino] -5-iodophenyl} acrylamide (I-RMFZ), was produced by adding iodine into the diaminophenyl group and changing the position of the trifluoromethyl group. A simulation of molecular docking was conducted using the AutoDock Vina software suite. IC50 of I-RMFZ was determined using a cell cytotoxicity assay. Results: I-RMFZ was successfully synthesized through multistep reactions. Molecular docking revealed that I-RMFZ interacts with the EGFR L858R/T790M mutation. Cytotoxicity assay demonstrated that I-RMFZ had a high selectivity towards EGFR L858R/T779M mutation. Conclusions: I-RMFZ is notable for radioiodination and is anticipated to be comparable with in vivo features of rociletinib. Thus, I-RMFZ can potentially be developed as an imaging agent for NSCLC through preclinical assay.

    DOI: 10.56499/jppres23.1743_12.2.231

    Web of Science

    Scopus

  2. A simple method to shorten the apparent dead time in the dosimetry of Lu-177 for targeted radionuclide therapy using a gamma camera

    Nakanishi, K; Fujita, N; Abe, S; Nishii, R; Kato, K

    PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS   Vol. 119   page: 103298   2024.3

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    Language:English   Publisher:Physica Medica  

    Background: The dead-time loss reportedly degrades the accuracy of dosimetry using a gamma camera for targeted radionuclide therapy with Lu-177; therefore, the dead-time loss needs to be corrected. However, the correction is challenging. In this study, we propose a novel and simple method to shorten the apparent dead time rather than correcting it through experiments and Monte Carlo simulations. Methods: An energy window of 208 keV ± 10 % is generally used for the imaging of Lu-177. Lower-energy gamma photons and X-rays of Lu-177 do not contribute to image formation but lead to dead-time losses. In our proposed method, a thin lead sheet was used to shield gamma photons and X-rays with energies lower than 208 keV, while detecting 208 keV gamma photons that penetrated the thin sheet. We measured and simulated the energy spectra and count rate characteristics of a clinical gamma camera system using a cylindrical phantom filled with a Lu-177 solution. Lead sheets of 1.0- and 0.5-mm thicknesses were used as thin shields, and the dead-time losses in tumour imaging with consumed Lu-177 were simulated. Results: The apparent dead times with lead sheets of 1.0- and 0.5-mm thicknesses and without a lead sheet were 1.7, 1.9, and 5.8 µs for an energy window of 208 keV ± 10 %, respectively. The dead-time losses could be reduced from 10 % to 1.3 % using the 1.0-mm thick lead sheet in the simulated imaging of tumour. Conclusion: Our method is promising in clinical situations and studies on Lu-177 dosimetry for tumours.

    DOI: 10.1016/j.ejmp.2024.103298

    Web of Science

    Scopus

    PubMed

  3. A first-in-man study of [<SUP>18</SUP>F] FEDAC: a novel PET tracer for the 18-kDa translocator protein

    Tamura, K; Nishii, R; Tani, K; Hashimoto, H; Kawamura, K; Zhang, MR; Maeda, T; Yamazaki, K; Higashi, T; Jinzaki, M

    ANNALS OF NUCLEAR MEDICINE     2024.1

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    Language:English   Publisher:Annals of Nuclear Medicine  

    Purpose: N-benzyl-N-methyl-2-[7, 8-dihydro-7-(2-[18F] fluoroethyl) -8-oxo-2-phenyl-9H-purin-9-yl] acetamide ([18F] FEDAC) is a novel positron emission tomography (PET) tracer that targets the translocator protein (TSPO; 18 kDa) in the mitochondrial outer membrane, which is known to be upregulated in various diseases such as malignant tumors, neurodegenerative diseases, and neuroinflammation. This study presents the first attempt to use [18F]FEDAC PET/CT and evaluate its biodistribution as well as the systemic radiation exposure to the radiotracer in humans. Materials and Methods: Seventeen whole-body [18F]FEDAC PET/CT (injected dose, 209.1 ± 6.2 MBq) scans with a dynamic scan of the upper abdomen were performed in seven participants. Volumes of interest were assigned to each organ, and a time–activity curve was created to evaluate the biodistribution of the radiotracer. The effective dose was calculated using IDAC-Dose 2.1. Results: Immediately after the intravenous injection, the radiotracer accumulated significantly in the liver and was subsequently excreted into the gastrointestinal tract through the biliary tract. It also showed high levels of accumulation in the kidneys, but showed minimal migration to the urinary bladder. Thus, the liver was the principal organ that eliminated [18F] FEDAC. Accumulation in the normal brain tissue was minimal. The effective dose estimated from biodistribution in humans was 19.47 ± 1.08 µSv/MBq, and was 3.60 mSV for 185 MBq dose. Conclusion: [18F]FEDAC PET/CT provided adequate image quality at an acceptable effective dose with no adverse effects. Therefore, [18F]FEDAC may be useful in human TSPO-PET imaging.

    DOI: 10.1007/s12149-023-01895-0

    Web of Science

    Scopus

    PubMed

  4. Synthesis and initial <i>in vitro</i> evaluation of olmutinib derivatives as prospective imaging probe for non-small cell lung cancer

    Fawwaz, M; Mishiro, K; Arwansyah; Nishii, R; Ogawa, K

    BIOIMPACTS   Vol. 14 ( 1 ) page: 27774   2024.1

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    Language:English   Publisher:BioImpacts  

    Introduction: Imaging a non-small cell lung cancer (NSCLC) using radiolabeled tyrosine kinase inhibitors (TKIs) has attracted attention due to their unique interaction with the target epidermal growth factor receptor (EGFR). Olmutinib (OTB) is one of the third-generation EGFR TKIs, which selectively inhibit EGFR L858R/T790M mutation. In this study, we aim to estimate the interaction of the iodinated OTB (I-OTB)-receptor complex by molecular docking. Furthermore, we will synthesize the I-OTB and evaluate its activity toward EGFR L858R/T790M by in vitro cytotoxicity assay. Methods: A molecular docking simulation was carried out using an AutoDock Vina program package to estimate the interaction of the ligand-receptor complex. The I-OTB, N-{3-iodo-5-[(2- {[4-(4-methylpiperazin-1-yl)phenyl]aminothieno{3,2-d}pyrimidin-4-yl)oxy]phenyl} acrylamide, was synthesized by introducing an iodine atom in the phenyl group in the 3-aryloxyanilide structure. The half inhibitory concentration (IC50) was determined by employing a 2-(2-methoxy- 4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium monosodium salt (WST- 8) assay to evaluate the activity of I-OTB. Results: The docking study exhibited that I-OTB could take an interaction similar to that of the parent compound. We successfully synthesized I-OTB and confirmed its structure by instrumental analysis. The binding energy of OTB and I-OTB in complex with EGFR T790M are -8.7 and -7.9 kcal/mol, respectively. The cytotoxicity assay showed that I-OTB also has an affinity towards the EGFR L858R/T790M mutation with the IC50 10.49 ± 5.64 μM compared to the EGFR wild type with the IC50 over than 10 μM. Conclusion: The cytotoxicity effect of I-OTB was comparable to that of OTB. This result indicates that the iodine substituent in OTB did not alter the parent compound selectivity toward double mutations EGFR L858R/T790M. Therefore, I-OTB is prominent for radioiodination, and [123/124I] I-OTB may be a promising candidate for EGFR L858R/T790M mutation imaging.

    DOI: 10.34172/bi.2023.27774

    Web of Science

    Scopus

    PubMed

KAKENHI (Grants-in-Aid for Scientific Research) 3

  1. Clinical PET/CT study with [11C]MEPRO, a specific transporter target for pancreatic cancer

    Grant number:23K07170  2023.4 - 2026.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Principal investigator 

    Grant amount:\4680000 ( Direct Cost: \3600000 、 Indirect Cost:\1080000 )

  2. 新規アミノ酸PET薬剤を用いた脳腫瘍の分子イメージング研究

    Grant number:23K07085  2023.4 - 2026.3

    科学研究費助成事業  基盤研究(C)

    山本 由佳, 須藤 仁美, 西山 佳宏, 西井 龍一, 畠山 哲宗, 則兼 敬志

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    Authorship:Coinvestigator(s) 

    脳腫瘍は予後不良でその分子生物学的特徴を明らかにするため、アミノ酸PET薬剤の11C-METを用いたPET検査が行われることが多い。しかし、遺伝子変異の有無などの予測法はまだ確立されていない。
    新規アミノ酸PET薬剤である11C-MeLeuを脳腫瘍に応用し、最適な検査法の確立、脳腫瘍でのSLC6A20との関係を明らかにする。また、悪性度評価、遺伝子変異の有無などとの関係を調べ、従来の11C-MET PETと比べてこれら診断能が向上できるかを検討する。腫瘍特異的なPET検査を行うことで、脳腫瘍の診断能の向上と生物学的特徴の把握が容易になり、最適な診断法の確立に繋がる。

  3. Development of theranostics agents targeting sodium glucose co-transporter

    Grant number:21H02865  2021.4 - 2025.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Coinvestigator(s)