Astaxanthin suppresses the malignant behaviors of nasopharyngeal carcinoma cells by blocking PI3K/AKT and NF-κB pathways via miR-29a-3p

Background As a natural extraction, astaxanthin is gaining increasing attention because of its safety and anti-tumor properties. It has been reported to participate in the progression of various types of cancer such as gastric cancer and ovarian cancer. Nevertheless, the role of astaxanthin in nasopharyngeal carcinoma (NPC) has not been investigated.Object The study aimed to explore the anticancer mechanism of astaxanthin in regulating NPC cell proliferation, cell cycle progression, apoptosis, migration, and invasion.Methods Human NPC cells (C666-1) were treated with different concentrations of astaxanthin (0, 1, 10, 20 mg/mL) followed by detection of cell viability. Then, C666-1 cell proliferation, apoptosis, cell cycle progression, invasion, and migration in response to 10 mg/mL astaxanthin, LY294002 (PI3K/AKT inhibitor) or parthenolide (PTL; NF-kappa B inhibitor) treatment were measured using cell counting kit-8 assay, colony forming assay, flow cytometry analyses, Transwell assay, and wound healing assay, respectively. Western blotting was performed to quantify protein levels of factors involved in PI3K/AKT and NF-kappa B signaling pathways, cell cycle phase markers (Cyclin D1, p21) and apoptotic markers (Bcl-2 and Bax).Results C666-1 cell proliferation, invasion, and migration were significantly suppressed by astaxanthin while cell apoptosis and cell cycle arrest at G1 phase were effectively enhanced in the context of 10 mg/mL astaxanthin. Protein levels of p-AKT, p-P65 and p-I kappa B levels were suppressed by astaxanthin treatment. After LY294002 or PTL treatment, the suppressive impact of astaxanthin on C666-1 cell process was strengthened, accompanied by the more obvious decrease in cell activity and cell colony number, more enhanced cell apoptosis and G1 phase arrest, and further inhibited cell migration and invasion. Moreover, the inhibitory effect of astaxanthin on Cyclin D1 and Bcl-2 protein levels as well as the promoting impact of astaxanthin on p21 and Bax were also amplified in combination with LY294002 or PTL treatment.Conclusions Astaxanthin significantly suppresses NPC cell proliferation, cell cycle arrest, migration, invasion while promoting cell apoptosis by inactivating PI3K/AKT and NF-kappa B pathways. The study first reveals the anticancer role of astaxanthin in NPC, providing a potential candidate for NPC treatment.