Fig. 1

MiR-224 is hypoxia-responsive and upregulated by HIF-1α in gastric cancer cells. a HIF-1α expression was analyzed by Western blot in SGC-7901 and MGC-803 cells under hypoxia and normoxic condition. GAPDH was employed as a loading control. b MiR-224 expression was analyzed by Northern blotting in SGC-7901 and MGC-803 cells under hypoxia or normoxic condition. U6 snRNA was used as an internal control. The graph represented the relatively quantitative expression of miR-224. c MiR-224 expression was analyzed by real-time PCR in SGC-7901 cells exposed to hypoxia for 6, 24 and 48 h. U6 snRNA was used as an internal control. d SGC-7901 and MGC-803 cells were transfected with either HIF-1α overexpressing plasmid or HIF-1α siRNA or controls, and then subjected to Western blot or real-time PCR to determine HIF-1α or miR-224 expression levels. *P < 0.05, **P < 0.01