Geraniol inhibits cell growth and promotes caspase-dependent apoptosis in nasopharyngeal cancer C666-1 cells via inhibiting PI3K/Akt/mTOR signaling pathway

Abstract

BackgroundNasopharyngeal carcinoma (NPC) is a major type of head and neck cancer that develops from the nasopharynx with a highly distorted cultural and regional prevalence. ObjectiveThe present work was aimed at discovering the anticancer activity of geraniol on C666-1 cells by inhibiting PI3K/Akt/mTOR signaling and promoting apoptosis. MethodologyThe viability of geraniol (5–50 µM)-treated C666-1 cells was investigated using an MTT assay. The MMP levels were evaluated using JC-1 staining. The apoptosis level was studied by dual staining, DAPI staining, and flow cytometry techniques. The oxidative stress markers (TBARS, SOD, and GSH) and apoptotic biomarkers (Bcl-2, Bax, caspase-3, and −9) in the geraniol-treated C666-1 cells were analyzed using respective kits. The RT-PCR technique was done to evaluate the inhibition of PI3K/Akt/mTOR signaling in the geraniol-treated C666-1 cells. ResultsThe outcomes of the MTT assay demonstrated that geraniol decreased C666-1 cell viability. The geraniol treatment reduced MMP and promoted apoptosis in C666-1 cells, which is evidenced by the fluorescent staining assay results. The flow cytometry assay results also confirmed the occurrence of apoptosis in the geraniol-treated C666-1 cells. The levels of TBARS were increased, while decreased GSH and SOD levels were observed in the geraniol-treated C666-1 cells. The geraniol also promoted pro-apoptotic gene expressions, including Bax, caspase-3, and -9, and additionally inhibited PI3K/Akt/mTOR signaling in the C666-1 cells. ConclusionThe present results elucidate that geraniol is an effective anticancer agent for NPC. It can effectively inhibit cell growth, promote apoptosis, and inhibit the PI3K/Akt/mTOR pathway. Therefore, it can be an effective antitumor drug for NPC treatment.