Crocetin suppresses angiogenesis through inhibiting Sonic hedgehog signaling pathway in gastric cancer

BackgroundCrocetin is an active component of saffron stigma, which has important therapeutic effects on various diseases including tumors, arthritis, hemorrhages, etc. However, the effects of crocetin on gastric cancer (GC) cells and their underlying mechanisms remain unclear.MethodsCell counting kit‑8 (CCK‑8), transwell assays, F-actin staining, tube formation and vasculogenic mimicry (VM) assays were used to examine the effects of crocetin on cell proliferation, migration and angiogenesis in GC. Enzyme linked immunosorbent assay (ELISA) and Western blot assay were performed to evaluate expression level of Sonic hedgehog (Shh) signaling and activation of epithelial‑mesenchymal transition (EMT) in GC cells treated with or without crocetin. Proliferation of xenograft tumors was detected by immunohistochemistry. ResultsCrocetin significantly inhibited tube formation of human umbilical vein endothelial (HUVEC) cells and VM formation of GC cells, as well as its proliferation, invasion and migration. Crocetin destroyed cytoskeleton and mosaic vessels formed by HUVEC and GC cells. Furthermore, we found that crocetin suppressed cell proliferation, migration, EMT, tube and VM formation through inhibiting Shh signaling pathway. Utilization of recombinant Shh reversed the suppressing effects of crocetin on cell proliferation, migration, angiogenesis and EMT. In addition, anti-tumor effect of crocetin was confirmed in xenograft tumors.ConclusionsCrocetin suppressed GC progression by inhibiting cell proliferation, migration and angiogenesis including tubes formed by HUVEC cells and VM vessels formed by GC cells, which were mediated by suppressing Shh signaling pathway. These results indicated that crocetin may function as an effective therapeutic drug against GC.