Figure 1.

Hypoxia induces transcriptional and translational up-regulation of Noxa. SK-N-MC neuroblastoma cells in serum- and glucose-deficient medium were subjected to hypoxic condition (0.5% O₂) for the indicated times. (A) cDNA was synthesized from the total RNAs extracted from SK-N-MC cells exposed to hypoxia and subjected to RT-PCR analysis. 32 and 26 cycles of amplification were performed for Noxa and GAPDH, respectively. Fold increases of Noxa expression (mean ± SD) were presented using densitometry. Noxa expression level at 0 h was arbitrarily defined as 1. *, a statistically significant difference in Noxa expression levels (P < 0.05 in A and C). (B) A representative RT-PCR result. (C) 30 μg cell lysates extracted from hypoxia-exposed cells were subjected to Western blot analysis using polyclonal anti-Noxa and β-tubulin antibodies. Fold increases of Noxa protein expression was presented. Noxa expression level at 0 h was arbitrarily defined as 1. (D) Representative Western blot.