Compositions, kits, and methods for therapeutic screening, diagnostics, and cancer treatment based on the identification or use of the different states of cancer stem cells, including cancer stem cells in the EMT (epithelial to mesenchymal transition) MET (mesenchymal to epithelial transition), and EMT-MET states are disclosed. In some methods, a subject is treated with one therapeutic that targets EMT cancer stem cells and a second therapeutic that targets MET cancers stem cells. In certain methods, the different states of cancer stem cells are distinguished based on markers CD44+CD24−, EpCam−CD49P+ (for EMT cancers stem cells), ALDH+ and EPCam+CD49r− (for MET cancers stem cells), and CD44+CD24−ALDH+ (for EMT-MET cancer stem cells). In particular methods, micro RNAs are used to transition to one particular cancer stem cell type (e.g., mir-100 for EMT and mir-93 for MET).
