Fig. 3.

PVT1 promotes NPC cell proliferation via HIF-1α. a The signaling pathways response upon PVT1 knockdown by Gene KGEE analyses. Quantitative RT-PCR (b) and WB (c) analyses of effects of PVT1 knockdown on HIF-1α activation. d Quantification of HIF-1α protein in c. e Reduction of HIF-1α mRNA stability in PVT1 knockdown HNE-1 cells compared with control cells. Cells were treated with 1 μg/ml actinomycin D and RNA was extracted at the time of 0, 1, and 2 h. f HIF-1α protein expression assays for HNE-1 and CNE-1 under hypoxia conditions (1% O₂). g Quantification of HIF-1α protein in f. Cell proliferation (h) and colony formation (i) assays for HNE-1 cells under hypoxic conditions. Hypoxia induced the cell proliferation and colony formation of NPC cells. The cell proliferation and colony formation abilities of NPC cells under hypoxic conditions were suppressed by PVT1 knockdown, and these suppressed cell proliferation and colony formation abilities of NPC cells were restored by HIF-1α overexpression. Error bars ± SD. *P < 0.05. **P < 0.01. ***P < 0.001. Data are representative from three independent experiments