2′-Hydroxyflavanone induces apoptosis through Egr-1 involving expression of Bax, p21, and NAG-1 in colon cancer cells

Scope Natural flavanones exhibit cancer preventive and/or therapeutic effects. The objective of this study was to investigate the molecular mechanism underlying the action of the antitumor activity of hydroxyflavanone using the HCT116 colon cancer cell line. Methods and results We investigated the effect of hydroxyflavanones on antitumor activity. We found that 2′‐hydroxyflavanone (2′‐HF) potently inhibited the clonogenicity of HCT116 cells. 2′‐HF triggered apoptosis in both wild‐type and p53‐null HCT116 cells, as revealed by DNA fragmentation and caspase activation. 2′‐HF upregulated nonsteroidal anti‐inflammatory drug‐activated gene 1 (NAG‐1) expression through induction of Egr‐1. Silencing of NAG‐1 or Egr‐1 using small interfering RNA (siRNA) could attenuate 2′‐HF‐induced apoptosis. Egr‐1 also upregulated the proapoptotic gene Bax and the cell cycle inhibitor p21. Conclusion Dietary 2′‐HF may possess antitumor activity against human colon cancer.