start-ver=1.4 cd-journal=joma no-vol=13 cd-vols= no-issue=8 article-no= start-page=1823 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210411 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Liquid Biopsy Targeting Monocarboxylate Transporter 1 on the Surface Membrane of Tumor-Derived Extracellular Vesicles from Synovial Sarcoma en-subtitle= kn-subtitle= en-abstract= kn-abstract=Simple Summary Synovial sarcoma (SS) is associated with a high risk of recurrence and poor prognosis, and no biomarker useful in monitoring tumor burden exists. We identified monocarboxylate transporter 1 (MCT1) expressed in extracellular vesicles (EVs) derived from synovial sarcoma as a potential such marker. Circulating levels of MCT1(+)CD9(+) EVs were significantly correlated with tumor volume in a SS mouse model. Serum levels of MCT1(+)CD9(+) EVs reflected tumor burden and treatment response in SS patients. Patients with MCT1 expression on the plasma membrane have significantly worse overall survival than those with nuclear expression. Silencing of MCT1 reduced the malignant phenotype including cellular viability, migration, and invasion of SS cells. MCT1 may thus be a promising novel target for liquid biopsies and a novel therapeutic target. The lack of noninvasive biomarkers that can be used for tumor monitoring is a major problem for soft-tissue sarcomas. Here we describe a sensitive analytical technique for tumor monitoring by detecting circulating extracellular vesicles (EVs) of patients with synovial sarcoma (SS). The proteomic analysis of purified EVs from SYO-1, HS-SY-II, and YaFuSS identified 199 common proteins. DAVID GO analysis identified monocarboxylate transporter 1 (MCT1) as a surface marker of SS-derived EVs, which was also highly expressed in SS patient-derived EVs compared with healthy individuals. MCT1(+)CD9(+) EVs were also detected from SS-bearing mice and their expression levels were significantly correlated with tumor volume (p = 0.003). Furthermore, serum levels of MCT1(+)CD9(+) EVs reflected tumor burden in SS patients. Immunohistochemistry revealed that MCT1 was positive in 96.7% of SS specimens and its expression on the cytoplasm/plasma membrane was significantly associated with worse overall survival (p = 0.002). Silencing of MCT1 reduced the cellular viability, and migration and invasion capability of SS cells. This work describes a new liquid biopsy technique to sensitively monitor SS using circulating MCT1(+)CD9(+) EVs and indicates the therapeutic potential of MCT1 in SS. en-copyright= kn-copyright= en-aut-name=YokooSuguru en-aut-sei=Yokoo en-aut-mei=Suguru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FujiwaraTomohiro en-aut-sei=Fujiwara en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YoshidaAki en-aut-sei=Yoshida en-aut-mei=Aki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UotaniKoji en-aut-sei=Uotani en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MoritaTakuya en-aut-sei=Morita en-aut-mei=Takuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KiyonoMasahiro en-aut-sei=Kiyono en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=HaseiJoe en-aut-sei=Hasei en-aut-mei=Joe kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=NakataEiji en-aut-sei=Nakata en-aut-mei=Eiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=KunisadaToshiyuki en-aut-sei=Kunisada en-aut-mei=Toshiyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=IwataShintaro en-aut-sei=Iwata en-aut-mei=Shintaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=YonemotoTsukasa en-aut-sei=Yonemoto en-aut-mei=Tsukasa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=UedaKoji en-aut-sei=Ueda en-aut-mei=Koji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=OzakiToshifumi en-aut-sei=Ozaki en-aut-mei=Toshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= affil-num=1 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Orthopaedic Surgery, Okayama Rosai Hospital kn-affil= affil-num=5 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=7 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=8 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Orthopaedic Surgery, Chiba Cancer Center kn-affil= affil-num=11 en-affil=Department of Orthopaedic Surgery, Chiba Cancer Center kn-affil= affil-num=12 en-affil=Cancer Precision Medicine Center, Japanese Foundation for Cancer Research kn-affil= affil-num=13 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences kn-affil= en-keyword=liquid biopsy kn-keyword=liquid biopsy en-keyword=synovial sarcoma kn-keyword=synovial sarcoma en-keyword=monocarboxylate transporter 1 kn-keyword=monocarboxylate transporter 1 en-keyword=extracellular vesicles kn-keyword=extracellular vesicles en-keyword=non-invasive biomarker kn-keyword=non-invasive biomarker END