Abstract 2960: Anti-cancer activity of NCTD: promotion of pro-apoptosis and anti-invasion in human oral cancer cells

Abstract

Abstract Norcantharidin (NCTD), a demethylated analog of cantharidin isolated from blister beetles, has been used as a promising anticancer agent; however, the anti-tumor potentials of NCTD against human oral cancer has not been fully understood. Here, this study was aimed to investigate the pro-apoptotic and anti-invasive effect and its molecular targets of NCTD in human oral cancer cell lines. Trypan blue exclusion assay, live/dead assay, western blotting, 4-6-Diamidino-2-Phenylindole staining, flow cytometric analysis, Terminal Deoxynucleotidyl Transferase dUTP Nick end Labeling (TUNEL) assay, immunohistochemistry and tumor xenograft mice models were performed to investigate the pro-apoptotic effect of NCTD. Clonogenic, wound healing, invasion, zymography, western blotting and immunocytochemistry assays were performed to investigate the anti-invasive effect of NCTD. NCTD significantly inhibited cell growth and increased the number of dead cells in oral cancer cell lines. It induced the following apoptotic phenomena: (1) the cleavages of poly (ADP-ribose) polymerase and casepase-3; (2) increase in apoptotic morphological changes (nuclear condensation and fragmentation); (3) increase in annexin V-positive cells or sub-G1 population of cells. NCTD significantly activated the p38 mitogen-activated protein kinase (MAPK) pathway. A p38 MAPK inhibitor (SB203580) partially attenuated NCTD-induced apoptosis in oral cancer cell lines. NCTD strongly suppressed tumor growth in the tumor xenograft bearing HSC-3 cells, and the number of TUNEL-positive cells increased in NCTD-treated tumor tissues. Also, NCTD markedly suppressed the colony formation, migration, and invasion of YD-15 cells as well as the activities of MMP-2 and MMP-9. It disrupted F-actin reorganization through suppressing the FAK/Paxillin axis. Moreover, NCTD exhibited a powerful anti-invasive effect compared with that of PF-562271. Collectively, these results suggest that NCTD has a potential pro-apoptotic and anti-invasive activity against oral cancer cell lines. Therefore, these results suggest that NCTD could be a potential anticancer drug candidate for the treatment of human oral cancer. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and future Planning [2017R1D1A1B03029317, 2018R1D1A1B07043080, and 2019R1A2C1085896]. Citation Format: Chi-Hyun Ahn, Kyoung-Ok Hong, Ji-Ae Shin, Seong Doo Hong, Sung-Dae Cho. Anti-cancer activity of NCTD: promotion of pro-apoptosis and anti-invasion in human oral cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2960.