Fig. 2.

Contribution of EMT and related signaling to PCSCs. a PCSCs with tumor-initiating capability can be identified by the expression of a distinct set of marker proteins, such as CD44, CD24, CD133 or c-Met. These CSCs can self-renew and differentiate into a number of cell types to generate the heterogeneity of the originating tumor. Inducers of EMT such as TGF-β, HH or Notch cause cells to acquire a CD44+ CD24 + ESA+ phenotype, reminiscent of PCSCs. b The PCSC cell surface markers CD24, and CD44 likely promote cell–cell interactions, the c-Met respond to secreted ligands to active developmental pathways, such as β-catenin, Notch and Stat3 in PCSCs. These pathways stimulate the expression of genes that regulate stem-cell properties, such as self-renewal