Figure 5

Expression of breast cancer stem cell markers CD44⁺/CD24^-/low in R2d and R2N1d cells and Modulation of HER2, Oct-4, AKT and HDAC6 expression in R2N1 cells by cell culture condition. A, higher frequency of CD44⁺/CD24^-/low cells was found in R2N1d cells than R2d cells (~50% vs. ~10%). R1 region denotes a small population of CD44^high cells which was increased in R2N1d cells. The fluorescence cut off level: high expression was fluorescence intensity > 10³; negative or low expression was fluorescence intensity < 10². B, CD44⁺/CD24^- cells sorted by flow cytometry tend to show contact-insensitive growth in confluent culture and gave rise to non-adherent cells in suspension. By flow cytometric analysis (C, E), and by western blotting (D), adherent cells and re-attached cells were found to be HER2⁺/OCT4⁺/AKT⁺/HDAC6⁺, whereas non-adherent cells were HER2^-/OCT4⁺/AKT ^-/HDAC6^-. The length of the scale bar of these photos is 100 μm.