PT  - JOURNAL ARTICLE
AU  - SHIMIZU, KATSUHIKO
AU  - OKITA, RIKI
AU  - SAISHO, SHINSUKE
AU  - MAEDA, AI
AU  - NOJIMA, YUJI
AU  - NAKATA, MASAO
TI  - Impact of COX2 Inhibitor for Regulation of PD-L1 Expression in Non-small Cell Lung Cancer
AID  - 10.21873/anticanres.12768
DP  - 2018 Aug 01
TA  - Anticancer Research
PG  - 4637--4644
VI  - 38
IP  - 8
4099  - http://ar.iiarjournals.org/content/38/8/4637.short
4100  - http://ar.iiarjournals.org/content/38/8/4637.full
SO  - Anticancer Res2018 Aug 01; 38
AB  - Background/Aim: There is no clear evidence in the literature regarding the regulation of programmed cell death-ligand 1 (PD-L1) expression by cyclo-oxygenase-2 (COX2). In this study, whether PD-L1 expression was regulated by COX2 activity was examined in vitro. Materials and Methods: Resected lung cancer specimens were analyzed for PD-L1 and COX2 expression by immunohistochemical analysis. Next, co-localization of PD-L1 and COX2 expression was analyzed by double-fluorescence staining. Lastly, the effect of COX2 inhibition on the expression of PD-L1 was examined using lung cancer cell lines. Results: PD-L1 expression was significantly correlated with COX2 expression in the resected specimens. The majority of cancer cells that expressed PD-L1 also co-expressed COX2. However, treatment of lung cancer cell lines with a COX2 inhibitor had no impact on PD-L1 expression. Conclusion: Our results suggest that COX2 inhibition might have no effect on the usage of immune checkpoint inhibitors in lung cancer treatment.