6-acrylic phenethyl ester-2-pyranone derivative induces apoptosis and G2/M arrest by targeting GRP94 in colorectal cancer

Colorectal cancer (CRC) is ranked the third driving reason for cancer death in the world. Surgery and chemotherapy have long been the first choices for cancer patients. However, the prognosis of CRC has never been satisfying, necessitating new effective treatment strategies. In our previous study, we synthesized compound 5o that showed high anticancer potential with a 6-acrylic phenethyl ester-2-pyranone backbone, but its mechanism of action (MOA) is not understood. To articulate the MOA of 5o against colon cancer, we evaluated the anti-cancer effect of compound 5o on CRC cells by cell proliferation assays. The MOA of 5o was explored through cell cycle assays and apoptosis assays. The target of 5o was identified by molecular dynamic assays, ATPase assays, and surface plasmon resonance (SPR) analysis. We discovered 5o, a compound capable of inhibiting CRC cell proliferation with 1/25 folds in IC50 values compared with NCM460 cells (normal human colonic epithelial cell line). 5o induces cell apoptosis in a dose-dependent manner through PI3K/Akt/FoxO1 and NF-κB signaling pathways. In addition, 5o arrests cell cycle at G2/M by regulating MAPKs (ERK1/2 and p38) pathway. We further confirmed that 5o inhibits ATPase activity of GRP94 (Glucose-regulated protein 94) with the IC50 1.45 ± 0.06 μM. Compound 5o inhibits GRP94 to trigger regulation of PI3K/Akt and MAPKs pathways. This study reveals that 5o is a promising therapeutic agent against CRC as a novel GRP94 inhibition.