TGF-β and Hypoxia/Reoxygenation Promote Radioresistance of A549 Lung Cancer Cells through Activation of Nrf2 and EGFR

Figure 1

Combined treatment with TGF-β and hypoxia induced the expression of Nrf2 and its downstream targets in a human non-small cell lung cancer cell line. A549 cells were treated with 1 ng/mL TGF-β and incubated under hypoxia for 2 h, followed by reoxygenation. Cells were prepared 8 h after cotreatment with TGF-β and hypoxia/reoxygenation. ((a) and (b)) Protein levels of Nrf2, HO-1, NQO-1, and Srx1 (a) and levels of phospho-Smad3, vimentin, and HIF-1α (b) were determined by western blotting. GAPDH was used as a loading control. (c) Proteins were detected with antibodies for Nrf2 and visualized by confocal microscopy. (d) RT-PCR analysis was performed to analyze the expression of Nrf2 mRNA and its target genes. The expression of HO-1 mRNA was determined by real-time PCR.

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