||REG Iα Promotes PD-L1 Expression in Esophageal Cancer Cells.
食道扁平上皮癌細胞において REG Iαは PD-L1 の発現を誘導する
脇田, 晃行WAKITA, Akiyuki
Regenerating gene (REG)Iα is known to contribute to carcinogenesis and to be associated with a poor prognosis in various cancers. Programmed death-1 ligand(PD-L1) is a negative regulator of T cell activation thought to play an important role in tumor evasion from host immunity.In the present study, we tested the hypothesis that the pro-survival effects of REG Iα in cancer reflect enhanced expression of PD-L1.We found that PD-L1 mRNA expression tended to correspond to REG Iα mRNA levels in esophageal squamous cancer cells, and that REG Iα expression significantly increased expression of both PD-L1 mRNA and protein in TE-5 and TE-9 squamous esophageal cancer cells transfected with REG Iα.In addition, immunohistochemical analysis of squamous cell esophageal cancer specimens revealed that the spatial distribution of PD-L1 expression corresponded to that of REG Iα. These findings suggest that REG Iα may suppress antitumor immunity by inducing PD-L1 expression.