Intestinal stem cells and the colorectal cancer microenvironment

Figure 2 Niche regulation of the normal intestinal epithelium and colorectal cancer. A: Intestinal subepithelial myofibroblasts (ISEMFs) surround the crypt. Along with paneth cells (P), they supply the stem cell niche with trophic signals. Developing intestinal cells migrate upwards towards the villus apex, during which time they are subject to niches among the various strata in the crypt. B: Redundant mediators expressed by ISEMFs and Paneth cells contribute to the preservation of the stem cell compartment and normal intestinal proliferation. C: The local niche immediately around CRC likely fosters tumor growth by activating stem cell pathways. CRC cells lacking proliferative ability may re-awaken upon re-entry into the niche. CRC: Colorectal cancer; BMP: Basic metabolic panel.