Fig. 1

M2 macrophage polarization is associated with Oct4 expression in lung cancer. a and b Flow cytometric analysis of M1 and M2 macrophages differentiated from PMA-stimulated THP-1 cells cocultured with the conditioned medium obtained from A549-Oct4 or A549-vector cells. Cells were then stained with PE-conjugated mouse anti-human CD86 or CD206 antibody, followed by stained with FITC-conjugated mouse anti-human CD68 antibody before flow cytometric analysis. Cells were first gated to exclude debris and dead cells (FSC vs. SSC), and then gated to exclude cell doublets (FL2-A vs. FL2-H). Within the CD68⁺ cells, differential expression of the M1 macrophage marker CD86 and M2 macrophage marker CD206 is based on CD86hi and CD206hi expression, respectively. Representative dot plots (upper) and histograms (middle), as well as percentages of M1 and M2 macrophages (lower) are shown. c Percentage of M2 macrophages differentiated from PMA-stimulated THP-1 cells cocultured with the conditioned medium obtained from Oct4 knockdown (shOct4) or control (shLuc) A549 cells. d and e Oct4 expression (D) and M-CSF production (E) in various human lung cancer cells detected by immunoblot analysis and ELISA, respectively. Expression of β-actin served as the loading control. f Positive correlation of Oct4 and M-CSF levels detected in D and E, as determined by Pearson’s correlation coefficient. All data shown represent means ± SEM (n = 3 to 4)