Down-regulation of ALDH3A1 relieves the resistance of oncogene-transformed Per2m/m cells against chemotherapeutic drugs.
A, the expression profiles of catalase, GSH peroxidase, and SOD3 in oncogene-transformed WT and Per2m/m cells. The results shown are representative of three independent experiments. B, effects of NAC, a GSH precursor, on the sensitivity of oncogene-transformed Per2m/m cells to chemotherapeutic drugs. Cells were treated with 1 μm MTX, 0.5 μm GEM, 50 μm VP-16, 5 μm VCR, or 50 μm L-OHP at the indicated concentrations in the presence or absence of NAC (2 mm). After treatment with each drug for 48 h, cell viability was determined by an ATP luminescent assay. Values are means ± S.D. (error bars) (n = 4). **, p < 0.01, significantly different from WT cells. C, effects of selective ALDH3A1 inhibitor CB29 on the sensitivity of oncogene-transformed Per2m/m cells to chemotherapeutic drugs. Cells were treated with chemotherapeutic drugs in the presence or absence of CB29 (30 μm). Cell viability was assessed 48 h after the initiation of drug treatment. Values are means ± S.D. (n = 4). **, p < 0.01, significantly different from WT cells. ##, p < 0.01, significantly different from Per2m/m cells without treatment with CB29. D, down-regulation of ALDH3A1 in oncogene-transformed Per2m/m cells by infection with shRNA-expressing vectors. E, effects of chemotherapeutic drugs on viability of Aldh3a1 down-regulated oncogene-transformed Per2m/m cells. Cell viability was assessed 48 h after the initiation of drug treatment. Values shown are means ± S.D. (n = 3–4). **, p < 0.01; *, p < 0.05, significantly different from WT cells. ##, p < 0.01; #, p < 0.05, significantly different from control shRNA-transfected oncogene-transformed Per2m/m cells (Per2m/m Control shRNA). F, influence of down-regulation of ALDH3A1 on the chemotherapeutic drug–induced production of ROS in oncogene-transformed Per2m/m cells. Values shown are means ± S.D. (n = 3). **, p < 0.01, significantly different between the two groups. ##, p < 0.01; #, p < 0.05, significantly different from the vehicle-treated group.