Role of Sonic Hedgehog signaling during progression from inflammation to cancer in the stomach

Figure 1 Neoplastic transformation of the stomach triggered by chronic inflammation. A: Helicobacter infection induces chronic inflammation mediated by Th1 cells leading to loss of Shh-secreting parietal cells; B: Inflammatory cytokines present in stomach influence expression of recruited MSCs, altering their expression profile leading to metaplastic changes, the preliminary step in gastric carcinogenesis. IL-1β: Interleukin-1beta; IFN: Interferon; TNF: Tumor necrosis factor; Shh: Sonic hedgehog; Cdx2: Caudal type homeobox 2; MSCs: Mesenchymal stem cells.