Figure 6
From: Radiation-induced non-targeted response in vivo: role of the TGFβ-TGFBR1-COX-2 signalling pathway
A signalling model for the induction of non-targeted responses in the out of field lung tissues after lower abdomen irradiation. Lower abdomen irradiation induces TGF-β ligands and receptors in non-targeted lung tissues but not released forms in the blood. TGF-β in stromal regions binds to its corresponding receptors on bronchial epithelial cells and activates a range of signalling pathways involving ERK, JNK, AKT, NFκB and Smad2, which lead to the upregulation of COX-2 in non-targeted lung tissues. COX-2 further induces prostaglandin production, oxidative DNA damage and mutagenesis in the non-targeted lung tissues.
