Fig. 1. Cephalomannine (CPM) inhibits cell growth and hypoxia-induced APEX1/HIF-1α pathways in hypoxic LC cells.

A H460 and A549 were treated with and without CPM under normoxia and hypoxia, and cell viability was examined at 24, 48, and 72 h. Data were expressed as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 compared with control cells. The results shown are representative of three independent experiments. B Hypoxia-induced APEX1/HIF-1α pathways in LC cells in vitro. Cell lines were cultured in normoxia and 1% O₂ for 0, 12, and 24 h. HIF-1α, APEX1, CA9, CXCR4, and EPO mRNA expression values were assessed by RT-qPCR. Gene expression is normalized to ACTB. Data were expressed as mean ± SEM (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 compared with control cells. C H460 and H1299 cells were incubated in 1% O₂ for 0, 12, and 24 h. Protein levels of HIF-1α and APEX1 were determined by western blotting. β-Actin were used as a control for western blots. n = 3. D H460 cells were cultured under hypoxia. APEX1 (green), HIF-1α (red), DAPI (blue) staining, and 3-channel merged images indicated the nuclear colocalization of HIF-1α. Scale bars, 50 μm. Data presented are representative of three independent experiments.