LAUSR

Although the neutrophil extracellular traps (NETs) are first recognized to function to trap invading microorganisms and eliminate them as a defense mechanism, the involvement of NETs in cancer metastasis is being elucidated. The mechanism of interaction between NET and cancer cells, however, remains to be fully understood. Here, we investigated the direct and indirect interaction between NETs and cancer. NETs were detected in surgically resected metastatic liver cancer tissue specimens. In direct co-culture, NETs actually attracted cancer cells with their web-like structure. Of note, indirect transwell co-culture of neutrophils and pancreatic cancer cells provoked NETs without the other stimuli. In addition, conditioned media derived from cancer cells also induced NETs. The co-culture of NETs and cancer cells dramatically accelerated their migration and invasion abilities. Further investigation revealed that NETs induced mesenchymal markers in cancer cells which was associated with upregulated epithelial to mesenchymal transition (EMT)-related transcriptional factors. Finally, the accelerated cancer migration and overexpression of mesenchymal markers induced via NETs were inhibited by pharmacological blockade of NETs including NADPH oxidase inhibitor, peptidylarginine deiminase inhibitor, and neutrophil elastase inhibitor. These results suggested that cancer cells and neutrophils reciprocally interact when they coexist and NETs drive malignant potentials via EMT, implicating NETs as a candidate therapeutic target. Citation Format: Hiroki Kajioka, Shunsuke Kagawa, Atene Ito, Kazuya Kuwada, Satoru Kikuchi, Shinji Kuroda, Ryuichi Yoshida, Hiroshi Tazawa, Toshiyoshi Fujiwara. The reciprocal interaction between neutrophil extracellular traps and cancer cells impacts on their malignant potentials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4519.