Fig. 5: IL-32γ inhibits constitutive activation of STAT5 signaling in CD133+ cancer stem cells.

a CD133+ cells were transfected with human IL-32γ, after 24 h of post transfection; expression of pSTAT5 was determined by immunofluorescence using a confocal microscope. b Human normal lung or NSCLC tissue sections (Grade I–III) were processed and stained; immunohistochemistry analyses for the expression of pSTAT5 were performed. The figures represent the sample of each cancer grade. c CD133+ A549 cells were treated with the STAT5 inhibitor (30 μM) for 24 h, and the expression of pSTAT5, pERK, CD133, and cleaved caspase-3 was determined by western blotting. d Effect of the STAT5 inhibitor on the colony formation of CD133+ CSCs. CD133+ isolated cells were cultured with or without the STAT5 inhibitor (30 μM) for 9 days in a six-well plate, which showed self-renewal capacity and tumor-sphere formation efficiency (after sphere formations, cells were stained with Crystal Violet) and photographed at 20× resolution. n = 5, *p < 0.05. e CD133+ A549 cells were transfected with human IL-32γ, after 24 h of post transfection, and it was treated with the STAT5 inhibitor (30 μM) for another 24 h. After that, pSTAT5, pERK, CD133, and cleaved caspase-3 determined by western blotting were detected using specific antibodies. f CD133+ A549 cells were transfected with human IL-32γ, after 24 h of post transfection, and it was transfected with STAT5 siRNA (100 nM) for another 24 h. After that, pSTAT5 and CD133 were determined by western blotting. Each band is representative of three independent experiments