The inhibitory effect of 5‐hydroxy‐hexamethoxyflavone on human colon cancer cells

Previously, we reported that 5‐hydroxy‐3,6,7,8,3′,4′‐hexamethoxyflavone(5HHMF), a polymethoxyflavone found in citrus peels, potently induced apoptosis and cell cycle arrest in multiple human colon cancer cells. Herein, we further investigated the anti‐cancer mechanisms of 5HHMF in colon cancer cells. Colony formation assay revealed that 5HHMF dose‐dependently inhibited colony formation of multiple colon cancer cells. Add‐back study showed that the inhibitory effect of 5HHMF was not associated with production of reactive oxygen species. Western blot analysis demonstrated 5HHMF decreased nuclear β‐Catenin levels and increased the post‐nuclear E‐cadherin level in a dose‐dependent manner. Moreover, 5HHMF selectively modified plasma membrane‐associated proteins such as K‐Ras, EGFR, and their downstream effectors, such as Akt and NFκB, which may contribute to its anti‐cancer effects. In addition, 5HHMF treatment inhibited the capillary tube formation of human umbilical vein endothelial cells (HUVEC) on matrigel, suggesting a potential anti‐tumor angiogenesis effect. Taken together, our results demonstrated that 5HHMF suppressed multiple oncogenic molecular events in colon cancer cells.