fig6

Figure 6. Transition of colon cancer cell phenotypes in relation to alteration of status of CXCR4 and CRC markers for acquiring irinotecan resistance. The G-protein coupled chemokine receptor, CXCR4, co-localizes with CRC stem cell markers, such as Lgr5, CD133, and CD44, which are thought to be associated with the epithelial-mesenchymal transition process and resistance to cancer drug therapy. CSC: Cancer stem cell; SDF-1α: stromal cell-derived factor-1α; TGFα: tumor growth factor-α; ERK1/2: extracellular signal-regulated kinase 1/2.