Figure 1
Model showing mechanisms of clonal expansion of transformed cells. At the initial step of carcinogenesis, transformation occurs in a single cell within an epithelial monolayer. (A) As the organized epithelium creates suppressive environments, a single mutation in some of oncogenes such as AKT is not sufficient to cause clonal expansion, and the transformed cell remains dormant. (B) For clonal expansion of the transformed cell, additional mutations that induce luminal translocation such as upregulation of MMP will be required. (C) Perturbation of cell-cell adhesions will also help transformed cells escape from the epithelial suppressive environments.
