Fig. 3
From: Natural compounds targeting major cell signaling pathways: a novel paradigm for osteosarcoma therapy
Wnt signaling pathway. a In the absence of the Wnt glycoprotein, β-catenin is degraded after being ubiquitinated and phosphorylated by the destruction complex. Target genes in the nucleus are not activated. b In the presence of Wnt, the glycoprotein binds to the extracellular transmembrane Frizzled receptor family (Fz and LRP5/6). Thereafter, the signal activates the protein Dishevelled (Dsh/DV1) in the cytoplasm. This binding results in disrupting the β-catenin destruction complex of various proteins including: axin, casein kinase 1α, adenomatous polyposis coli (APC), protein phosphatase 2A (PP2A), and glycogen synthase kinase 3 (GSK–3β). β-catenin translocates to nucleus where it can act as transcriptional coactivator of transcription factors of TCF/LEF family. Resveratrol and apigenin decrease protein expression of β-catenin