Fig. 2

Expression of hypoxia-induced EMT markers and stem cell markers. a E-cadherin expression decreased according to the length of exposure to hypoxia in four lung cell lines (BEAS-2B, A549, H292, and H226). Expression of fibronectin, vimentin, and α-SMA increased; although, the expression levels differed according to the duration of exposure to hypoxic stimuli. b Confocal microscopy images of E-cadherin, α-SMA, and CXCR4 expression. Expression of the epithelial cell marker E-cadherin was lost following hypoxic stimuli; although, the expression of the mesenchymal cell marker α-SMA and the stem cell marker CXCR4 increased following hypoxic stimuli. E-cadherin (gray), α-SMA (red), CXCR4 (green), and DAPI (blue) (scale bar = 50 μm). c The time-dependent mRNA and protein expressions of CXCR4 are shown. Compared with the normoxic condition, the cells exposed to the hypoxic condition displayed increased CXCR4 mRNA and protein expressions. The mRNA expressions of CXCR4 in each cell line increased as early as 2 h; although, the protein expressions were definite in 24 or 48 h according to the cell lines