Fig. 2: Schematic overview of the intestinal epithelium.
From: Cell competition in primary and metastatic colorectal cancer
Regeneration: Upon damage, all cell types in the intestinal villus and crypt can regenerate and repopulate. Regenerating cells activate a damage-response associated with specific gene expression as well as loss of differentiated morphology. Moreover, immune cells enter the tissue to combat inflammation. Homeostasis: Proliferation occurs in ISCs, and progeny differentiates as they move upwards along the villus. At the villus top, mature enterocytes are shed, maintaining a high cell turnover. In the center, gradients are shown as observed in homeostasis. EDAC: Early malignant cells are recognized by surrounding healthy epithelial cells and extruded locally from the tissue to prevent spread of cancer cells. Intestinal Cancer: When malignant cells are not recognized and extruded, they can progress. Upon gaining several oncogenic mutations, the cellular fitness of cancer cells increases and they gain the ability to eliminate surrounding wild-type epithelial cells.
