[The role and the molecular mechanism of abietic acid in the proliferation, invasion and migration of cisplatin-resistant nasopharyngeal carcinoma cells].

To investigate the effects and molecular mechanisms of abietic acid in the cell proliferation, invasion and migration of cisplatin-resistant nasopharyngeal carcinoma cells. ①Cisplatin-resistant C666/DDP cell line was constructed by increasing drug concentration method. ②The effects of abietic acid on proliferation, invasion and migration of C666/DDP cells were investigated by CCK-8 method, reactive oxygen species（ROS） and mitochondrial membrane potential（MMP） level assay and subcutaneous tumorigenesis assay in nude mice to detect the effects of abietic acid on proliferation and apoptosis of C666/DDP cells in vitro and in vivo. The effect of abietic acid on the proliferation and apoptosis of C666/DDP cells in vitro and in vivo was measured by Transwell assay. ③Western blot and IHC method to detect the expression of PI3K/AKT/mTOR pathway related proteins. ①The IC50 of cisplatin cytotoxicity to C666-1 was about 25 μmol/L. RI=25 μmol/L /4 μmol/L=6.25, resistance was obtained, and the C666-1-DDP resistant strain was successfully constructed. ②Abietic acid promoted apoptosis and inhibited proliferation of C666/DDP cells, and showed G2/M phase block; transwell showed that abietic acid inhibited C666/DDP cell migration and invasion, increased ROS level of C666/DDP cells and decreased MMP. Transwell showed that abietic acid inhibited the migration and invasion ability of C666/DDP cells, increased the ROS level of C666/DDP cells and decreased MMP. ③Animal experiments showed that abietic acid inhibited the proliferation of cisplatin-resistant nasopharyngeal carcinoma in vivo in a concentration gradient and suppressed the expression of PI3K/AKT/mTOR signaling pathway-related proteins. Abietic acid inhibits proliferation, invasion and migration of cisplatin-resistant nasopharyngeal carcinoma cells by a mechanism related to inhibition of PI3K/AKT/mTOR signaling pathway.