Fig. 4.

Inhibition of and/or knocking-out HIF-1α or miR-210 abolished Nano-Ni-induced Rad52 down-regulation. A–C BEAS-2B cells were pretreated with 1 µM of 17-AAG for 4 h, followed by treatment with 20 µg/mL of Nano-Ni for 24 h. D–F HIF-1α wild-type (+ / +) and knock-out (−/−) cells were treated with 20 µg/mL of Nano-Ni for 24 h. G–I BEAS-2B cells were transfected with mirVana™ miRNA inhibitor for has-miR-210-3p or Negative Control #1 for 24 h, followed by treatment with 20 µg/mL of Nano-Ni for another 24 h. A, D, G miR-210 expression was determined by real-time PCR. Values of miR-210 expression was normalized to the endogenous control U6 snRNA. Data are shown as mean ± SEM (n = 3–4). B–C, E–F, H–I Nuclear proteins were subjected to Western blot. Equal nuclear protein loading was verified by Coomassie Brilliant Blue staining. B, E, H are results of a single Western blot experiment, while C, F, I are quantified band densitometry readings averaged from at least 3 independent experiments ± SEM of Western blot results. *, p < 0.05 vs. control; #, p < 0.05 vs. group with Nano-Ni treatment, but without 17-AAG treatment (A, C), Nano-Ni-treated HIF-1α (+ / +) group (D, F), or group with Negative Control transfection and Nano-Ni treatment (G, I)