start-ver=1.4 cd-journal=joma no-vol=8 cd-vols= no-issue=12 article-no= start-page=e1671760 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20191022 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Intraperitoneal cancer-immune microenvironment promotes peritoneal dissemination of gastric cancer en-subtitle= kn-subtitle= en-abstract= kn-abstract= A solid tumor consists of cancer and stromal cells, which comprise the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are usually abundant in the TME, contributing to tumor progression. In cases of peritoneal dissemination of gastric cancer (GC), the contribution of intraperitoneal TAMs remains unclear. Macrophages from peritoneal washings of GC patients were analyzed, and the link between intraperitoneal TAMs and GC cells was investigated to clarify the interaction between them in peritoneal dissemination. Macrophages were predominant among leukocytes constituting the microenvironment of the peritoneal cavity. The proportion of CD163-positive TAMs was significantly higher in stage IV than in stage I GC. Co-culture with TAMs potentiated migration and invasion of GC. IL-6 was the most increased in the medium of in vitro co-culture of macrophages and GC, and IL-6 elevation was also observed in the peritoneal washes with peritoneal dissemination. An elevated concentration of intraperitoneal IL-6 was correlated with a poor prognosis in clinical cases. In conclusion, intraperitoneal TAMs are involved in promoting peritoneal dissemination of GC via secreted IL-6. TAM-derived IL-6 could be a potential therapeutic target for peritoneal dissemination of GC. en-copyright= kn-copyright= en-aut-name=SakamotoShuichi en-aut-sei=Sakamoto en-aut-mei=Shuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KagawaShunsuke en-aut-sei=Kagawa en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=KuwadaKazuya en-aut-sei=Kuwada en-aut-mei=Kazuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=ItoAtene en-aut-sei=Ito en-aut-mei=Atene kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KajiokaHiroki en-aut-sei=Kajioka en-aut-mei=Hiroki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KakiuchiYoshihiko en-aut-sei=Kakiuchi en-aut-mei=Yoshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=WatanabeMegumi en-aut-sei=Watanabe en-aut-mei=Megumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=KagawaTetsuya en-aut-sei=Kagawa en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=YoshidaRyuichi en-aut-sei=Yoshida en-aut-mei=Ryuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=KikuchiSatoru en-aut-sei=Kikuchi en-aut-mei=Satoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=KurodaShinji en-aut-sei=Kuroda en-aut-mei=Shinji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=TazawaHiroshi en-aut-sei=Tazawa en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=FujiwaraToshiyoshi en-aut-sei=Fujiwara en-aut-mei=Toshiyoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= affil-num=1 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=2 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=3 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=4 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=5 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=6 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=7 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=8 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=9 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=10 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=11 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=12 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= affil-num=13 en-affil=Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences kn-affil= en-keyword=Gastric cancer kn-keyword=Gastric cancer en-keyword=tumor-associated macrophages kn-keyword=tumor-associated macrophages en-keyword=tumor microenvironment kn-keyword=tumor microenvironment en-keyword=peritoneal dissemination kn-keyword=peritoneal dissemination END