Ultraviolet C Irradiation Induces Different Expression of Cyclooxygenase 2 in NIH 3T3 Cells and A431 Cells: The Roles of COX-2 Are Different in Various Cell Lines

• Main Authors: Ming-Hsiu Wu, Chun-Yi Hu, Ming-Hong Tai, Chien-Hui Weng, Dir-Pu Mon
• Format: Article
• Language: English
• Published: MDPI AG 2012-04-01
• Series: International Journal of Molecular Sciences
• Subjects: ultraviolet C (UVC); cyclooxygenases-2 (COX-2); prostaglandin E2 (PGE2); NIH 3T3 cells; A431 cells
• Online Access: http://www.mdpi.com/1422-0067/13/4/4351/

Ultraviolet C (UVC) is a DNA damage inducer, and 20 J/m2 of UVC irradiation caused cell growth inhibition and induced cell death after exposure for 24–36 h. The growth of NIH 3T3 cells was significantly suppressed at 24 h after UVC irradiation whereas the proliferation of A431 cells was inhibited until 36 h after UVC irradiation. UVC irradiation increased COX-2 expression and such up-regulation reached a maximum during 3–6 h in NIH 3T3 cells. In contrast, UVC-induced COX-2 reached a maximum after 24–36 h in A431 cells. Measuring prostaglandin E2 (PGE2) level showed a biphasic profile that PGE2 release was rapidly elevated in 1–12 h after UVC irradiation and increased again at 24 h in both cell lines. Treatment with the selective COX-2 inhibitor, SC-791, during maximum expression of COX-2 induction, attenuated the UVC induced-growth inhibition in NIH 3T3 cells. In contrast, SC-791 treatment after UVC irradiation enhanced death of A431 cells. These data showed that the patterns of UVC-induced PGE2 secretion from NIH 3T3 cells and A431 cells were similar despite the differential profile in UVC-induced COX-2 up-regulation. Besides, COX-2 might play different roles in cellular response to UVC irradiation in various cell lines.