Fig. 5.

CTK7A-mediated increase in Noxa expression was regulated by ROS generation in CoCl₂-treated GCCs. (A) Immunoblot analysis (n = 3) of AGS cells after treatment with SOD for 4 h followed by treatment with CoCl₂ (200 µM) and/or CTK7A (100 µM) for detection of Noxa and Hif1α expression. GAPDH was used as a loading control. Bars depict Noxa expression normalized to GAPDH (mean ± SEM, n = 3), *P < 0.05. (B) Western blotting (n = 3) of cell lysates after treatment with catalase (350 units/ml) for 4 h followed by above mentioned combination of CTK7A and CoCl₂ for detection of Noxa and Hif1α expression. Graphical presentation of Noxa expression was shown by bar diagrams (mean ± SEM, n = 3), *P < 0.05. (C) AGS cells were treated with CoCl₂ (200 µM) alone or in combination with CTK7A (100 µM) for 24 h with or without catalase pre-treatment (350 units/ml, 4 h). Cells were then incubated with fluorescence probe CM-H₂DCFDA at a final concentration of 1 µM for 10 min followed by fixation with paraformaldehyde at 37°C for 20 min. ROS generation was measured under a fluorescence microscope (Olympus, Japan). Scale bar, 20 µm. Bars depict mean fluorescence intensity (mean ± SEM, n = 3), *P < 0.05.