Abstract 454: ADAM proteases shed UL-16-binding protein 2 in human lung cancer cell lines

NKG2D is an activating receptor that is expressed in immune effector cells, and the ligands for which are expressed in transformed cells. NKG2D-NKG2D ligand system might play an essential role in the tumor immunity of host cells. We have previously reported that a member of NKG2D ligand family, UL-16-binding protein 2 (ULBP2), is predominantly expressed on the surface of lung cancer cells, and is shed and solubilized into the sera of the lung cancer patients. In addition, we showed that the soluble form of ULBP2 (sULBP2) aggravates the cytotoxicity of host immune effector cells. Therefore, shedding of ULBP2 from the surface of cancer cells might be a critical component of the immune escape mechanisms employed in lung cancer. In this study, we investigated the mechanism of ULBP2 shedding from the cell surfaces in human lung cancer cell lines. First, we compared the amount of ULBP2 expression on the surface of normal cells and that in the culture medium of various lung cancer cell lines. We observed a significant correlation among non-small-cell lung cancer (NSCLC) cell lines (r=0.835, P Citation Format: Kosuke Yamaguchi, Hiroki Hikumi, Shinji Matsumaga, Miyako Takata, Naoki Kinoshita, Kiyoshi Hashimoto, Masaki Nakamoto, Jun Kurai, Masanari Watanabe, Akira Yamasaki, Tadashi Igishi, Naoto Burioka, Eiji Shimizu. ADAM proteases shed UL-16-binding protein 2 in human lung cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 454. doi:10.1158/1538-7445.AM2013-454