Targeting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which has been clinically established for anticancer therapy, is the attractive strategy to specifically kill cancer cells through the death receptors. Nonetheless, its therapeutic potential is limited due to the resistance in cancer cells. Thus, in the present study, we evaluated the therapeutic potential of Decursin, a pyranocoumarin isolated from the Korean Angelica gigas root as a TRAIL sensitizer in a variety of resistant lung cancer cells. Co-treatment of Decursin with TRAIL synergistically induced apoptosis in TRAIL resistant lung cancer cells, A545, H1299, H596 and Calu-1. This synergistic effect through the induction of DR5 in Decursin treated cells was also confirmed by immunoblotting and immunoanalysis of endogeneous and surface expression of DR5, respectively. In contrast, in DR knockdown cells, combination treatment Decursin and TRAIL did not induce apoptosis at all. Furthermore, we found that DR5 induction by Decursin was mediated by ER-stress and its byproduct CHOP. Depletion of CHOP via siRNA transfection completely blocked Decusin induced apoptosis cell death in TRAIL resistant lung cancer cells. Taken together, induction of the DR5 via upregulation of CHOP and its inducer, ER stress, by Decursin leads to synergistically increase the TRAIL mediated cell death in TRAIL resistant lung cancer cells. Our results indicate that Decursin is a useful therapeutic strategy for overcoming TRAIL resistance in lung tumor treatment.

Key words: Decursin, DR-5, ER stress, CHOP, Trail resistant, Lung cancer

Conflict of Interests: The authors disclose no potential conflicts of interest.

Acknowledgment: This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea Government (MEST) (no. 2012-0005755).

Citation Format: Kim Jae Kwang. Decursin synergistically enhances TRAIL-induced apoptosis through CHOP dependent DR5 signaling in TRAIL resistant lung cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5118. doi:10.1158/1538-7445.AM2014-5118

©2014 American Association for Cancer Research.
2014