RRC ID 76362
著者 Gohara Y, Tomonobu N, Kinoshita R, Futami J, Audebert L, Chen Y, Komalasari NLGY, Jiang F, Yoshizawa C, Murata H, Yamamoto KI, Watanabe M, Kumon H, Sakaguchi M.
タイトル Novel extracellular role of REIC/Dkk-3 protein in PD-L1 regulation in cancer cells.
ジャーナル J Mol Med (Berl)
Abstract The adenovirus-REIC/Dkk-3 expression vector (Ad-REIC) has been the focus of numerous clinical studies due to its potential for the quenching of cancers. The cancer-suppressing mechanisms of the REIC/DKK-3 gene depend on multiple pathways that exert both direct and indirect effects on cancers. The direct effect is triggered by REIC/Dkk-3-mediated ER stress that causes cancer-selective apoptosis, and the indirect effect can be classified in two ways: (i) induction, by Ad-REIC-mis-infected cancer-associated fibroblasts, of the production of IL-7, an important activator of T cells and NK cells, and (ii) promotion, by the secretory REIC/Dkk-3 protein, of dendritic cell polarization from monocytes. These unique features allow Ad-REIC to exert effective and selective cancer-preventative effects in the manner of an anticancer vaccine. However, the question of how the REIC/Dkk-3 protein leverages anticancer immunity has remained to be answered. We herein report a novel function of the extracellular REIC/Dkk-3-namely, regulation of an immune checkpoint via modulation of PD-L1 on the cancer-cell surface. First, we identified novel interactions of REIC/Dkk-3 with the membrane proteins C5aR, CXCR2, CXCR6, and CMTM6. These proteins all functioned to stabilize PD-L1 on the cell surface. Due to the dominant expression of CMTM6 among the proteins in cancer cells, we next focused on CMTM6 and observed that REIC/Dkk-3 competed with CMTM6 for PD-L1, thereby liberating PD-L1 from its complexation with CMTM6. The released PD-L1 immediately underwent endocytosis-mediated degradation. These results will enhance our understanding of not only the physiological nature of the extracellular REIC/Dkk-3 protein but also the Ad-REIC-mediated anticancer effects. KEY MESSAGES: • REIC/Dkk-3 protein effectively suppresses breast cancer progression through an acceleration of PD-L1 degradation. • PD-L1 stability on the cancer cell membrane is kept high by binding with mainly CMTM6. • Competitive binding of REIC/Dkk-3 protein with CMTM6 liberates PD-L1, leading to PD-L1 degradation.
巻・号 101(4)
ページ 431-447
公開日 2023-4-1
DOI 10.1007/s00109-023-02292-w
PII 10.1007/s00109-023-02292-w
PMID 36869893
PMC PMC10090029
MeSH Adaptor Proteins, Signal Transducing / metabolism B7-H1 Antigen* Breast Neoplasms* Female Humans Intercellular Signaling Peptides and Proteins
リソース情報
ヒト・動物細胞 293T(RCB2202)