Curcumin is a natural compound extracted from the dried rhizomes of Curcuma (curcuma root or zedoary) that exhibits extensive pharmacological effects and low toxicity. The aim of the present study was to investigate whether curcumin inhibits cell proliferation and promotes apoptosis of laryngeal cancer through Bcl-2 and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), and by upregulating microRNA-15a (miR-15a). It was demonstrated that curcumin inhibits cell proliferation, and promotes apoptosis and increased caspase-3 activity of human laryngeal cancer cells. Furthermore, curcumin decreased Bcl-2 and PI3K protein expression, and decreased the phospho (p)-Akt protein expression of human laryngeal cancer cells. Furthermore, curcumin activated miR-15a expression by human laryngeal cancer cells. Suppression of miR-15a expression reversed the anticancer effect of curcumin on cell proliferation of human laryngeal cancer cells and increased Bcl-2 and PI3K/Akt protein expression in AMC-HN-8 cells treated with 40 µM of curcumin. The results of the present study suggest that curcumin inhibits cell proliferation and promotes apoptosis of laryngeal cancer cells through Bcl-2 and PI3K/Akt, and by upregulating miR-15a.
Keywords: apoptosis regulator Bcl-2; curcumin; laryngeal cancer; microRNA-15a; phosphoinositide 3-kinase/protein kinase B.