A combination of all-trans retinoic acid derivative and COX-2 inhibitor has anticancer effects in human pharyngeal carcinoma cells

Backgrounds and aims: Carcinogenesis is characterized by an unlimited growth of cells exacerbated by Cox-2 overexpression. Cox-2 inhibitors have been proven effective in preventing and treating tumors. In our previous studies, we found that 4-Amino-2-Trifluoromethylphenyl Retinate (ATPR) induces cell apoptosis and inhibits cell proliferation to exhibit anti-cancer properties. The use of ATRA as well as Cox-2 inhibitors in clinical settings can cause adverse reactions. It is unknown what the effects and mechanisms of co-administration of ATPR and Cox-2 inhibitors are. Results: A combination of ATPR and Cox-2 inhibitors, Celecoxib, inhibited pharyngeal cancer cell proliferation in vitro and induced apoptosis. The cell cycle was arrested at G0/G1 by activating P53 and CDNA1. By activating MAPK/JNK pathways, ATPR and Celecoxib led to intrinsic and extrinsic apoptosis in pharyngeal cancer cells. ATPR/Celecoxib combined treatment suppressed tumor growth in the pharyngeal cancer cell-derived xenograft mouse model by increasing the number of apoptotic cells. The expression of the RARA and PTGS2 genes was significantly increased in tumor tissue compared to non-tumor tissue in the clinical analysis of the head and neck squamous cell carcinoma dataset. An association was found between this and the level of intrinsic apoptotic signals. Furthermore, a survival analysis conducted over a period of five years indicated that higher levels of RARA expression were associated with a better clinical outcome. Conclusion: ATPR and celecoxib inhibit the proliferation of cancer cells as well as induce apoptosis. Co-administration of ATPR and Cox-2 inhibitors has the potential to be a novel treatment plan for cancer.