Helichrysetin (HEL), a
chalcone isolated from Alpinia katsumadai Hayata, has an antitumor activity in human lung and
cervical cancers. However, the inhibitory effect and underlying mechanism of HEL in
gastric cancer have not been elucidated. Here, HEL significantly inhibited the growth of
gastric cancer MGC803 cells in vitro and in vivo. HEL decreased expression and transcriptional regulatory activity of c-Myc and
mRNA expression of c-Myc target genes. HEL enhanced mitochondrial oxidative phosphorylation (OXPHOS) and reduced glycolysis as evidenced by increased mitochondrial
adenosine triphosphate (
ATP) production and excessive
reactive oxygen species (ROS) accumulation, and decreased the pPDHA1/PDHA1 ratio and Glyco-
ATP production.
Pyruvate enhanced OXPHOS after HEL treatment. c-Myc overexpression abolished HEL-induced inhibition of cell viability, glycolysis, and
protein expression of PDHK1 and LDHA. PDHK1 overexpression also counteracted inhibitory effect of HEL on cell viability. Conversely, c-Myc
siRNA decreased cell viability, glycolysis, and PDHK1 expression. NAC rescued the decrease in viability of HEL-treated cells. Additionally, HEL inhibited the overactivated mTOR/
p70S6K pathway in vitro and in vivo. HEL-induced cell viability inhibition was counteracted by an mTOR agonist. mTOR inhibitor also decreased cell viability. Similar results were obtained in SGC7901 cells. HEL repressed
lactate production and efflux in MGC803 cells. These results revealed that HEL inhibits
gastric cancer growth by targeting mTOR/
p70S6K/c-Myc/PDHK1-mediated energy metabolism reprogramming in
cancer cells. Therefore, HEL may be a potential agent for
gastric cancer treatment by modulating
cancer energy metabolism reprogramming.