京都大学 / 0048 / 新制・課程博士 / 博士(薬学) / 甲第18218号 / 薬博第808号 / 新制||薬||238(附属図書館) / 31076 / 京都大学大学院薬学研究科医療薬科学専攻 / (主査)教授 佐治 英郎, 教授 橋田 充, 教授 髙倉 喜信 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Yes / Prostate cancer is the 2nd most common cancer in men worldwide. Chemotherapeutic treatment of prostate cancer with mitoxantrone (MTX) has limited efficacy due to severe side effects in which cardiotoxicity and myelosuppression are the two major causes of its dose-limiting toxicity. This study aimed to obtain a poly (lactic-co-glycolic acid) (PLGA) nanoparticle that can precisely deliver MTX to the prostate cancer cells overexpressing the Prostate-specific membrane antigen (PSMA) receptor-sparing healthy tissues and co-loading Indocyanine green (ICG) as a fluorescent photothermal/photodynamic agent for precise combinatory therapy in prostate cancer. The biocompatible polymer PLGA was covalently modified with the peptide of sequence (WQPDTAHHWATL) to actively target the PSMA receptor. Factors like the peptide-to-polymer ratio or the peptide's orientation during the polymer's chemical modification were investigated to enhance the active targeting of the nanoparticles (NPs). NPs were characterised using dynamic light scattering, scanning electron microscopy, and UV–vis spectroscopy to determine their morphological and colloidal properties and optimal MTX and ICG encapsulation efficiency. Quantitative FACS analysis of LNCaP and PC-3 cells incubated with Nile Red-labelled non-targeted PLGA or PLGA-PSMA targeted NPs was assessed to identify the best formulation that bound selectively to PSMA. The orientation of the peptide conjugated to the polymer, which has the C-terminal end of the peptide sequence accessible for interaction with the cell receptor, maximises the targeting capacity of the system. Photothermal experiments using 808 nm near-infrared laser irradiation were conducted, and cytotoxicity was assessed using the resazurin viability assay. Remarkably, our results confirmed the safety and efficacy of a targeted and activatable therapy using polymeric NPs functionalised with the peptide and co-loaded with MTX and ICG. This pioneer nanosystem opens new perspectives for exploring advanced targeted delivery in prostate cancer. It offers a straightforward methodology for functionalising drug delivery systems with bioactive peptides that can be applied to different types of cancer. / Royal Society Research Grant (RGS\R1\221399); MRC Confidence in Concept grant (RM0039); University of Bradford. This work was partially supported by a grant to I.H. (PID2021-122216OB-I00) funded by the Spanish Ministry of Economy, Industry and Competitiveness at the European Regional Development Fund

Development of nanochemical tools targeting receptors in the tumor microenvironment Targeting the receptors in the tumor microenvironment is crucial for the future development of targeted therapies, precision medicine and immunotherapy of cancer. The options available now are, however, limited by the availability of specific ligands. The advances in the field strongly rely on the use of antibodies and genetic modifications of immune cells. Availability of small molecules targeting the receptors of interest would allow further development of alternative strategies as well as deepen our understanding of the underlying mechanisms of cancer development, progression and clearance. In the search for new small-molecule ligands and their use for receptor targeting, the prostate-specific membrane antigen (PSMA) and the immune receptors CD3 and CD64 were selected as model targets. The selected method - the phage display of bicyclic peptides - utilizes chemical modification of the displayed three-cysteine peptides to achieve their cyclization and formation of bicycles. The panning of a peptide library displayed on the phages and probed with PSMA revealed a reproducibly-selected amino acid sequence. Interestingly, the phage clone carrying this sequence was a specific binder of PSMA, but the synthesized peptide alone...

Glutamate carboxypeptidase II (GCPII), also known as prostate-specific membrane antigen (PSMA), is a membrane metallopeptidase overexpressed on most prostate cancer cells. Additionally, GCPII also attracted neurologists' attention because it cleaves neurotransmitter N-acetyl-L-aspartyl-L-glutamate (NAAG). Since NAAG exhibits neuroprotective effects, GCPII may participate in a number of brain disorders, which were shown to be ameliorated by GCPII selective inhibitors. Therefore, GCPII has become a promising target for imaging and prostate cancer targeted therapy as well as therapy of neuronal disorders. Globally, prostate cancer represents the second most prevalent cancer in men. With the age, most men will develop prostate cancer. However, prostate tumors are life threatening only if they escape from the prostate itself and start to spread to other tissues. Therefore, considerable efforts have been made to discover tumors earlier at more curable stages as well as to target aggressive metastatic cancers that have already invaded other tissues and become resistant to the standard treatment. Since patients undergoing a conventional therapy (a combination of chemotherapy and surgery) suffer from severe side effects, more effective ways of treatment are being searched for. Novel approaches include selective...