A, B. HCT116 (A) and KM12C (B) cells pre-treated with PCMV, Flag-ZFP91 or HA-HIF-1α together with control siRNA or HIF-1α siRNA, and subjected to MTT assay on days 1, 2, 3 and 4 under normoxic conditions. Data represented as mean ± standard deviation of three independent experiments (*p<0.05, **p<0.01). C, D. HCT116 and KM12C cells pre-treated with PCMV, Flag-ZFP91 or HA-HIF-1α together with control siRNA or HIF-1α siRNA under normoxic conditions, and then cells proliferation was measured by colony formation assay (C) and EdU assay (D). Data represented as mean ± standard deviation of three independent experiments (*p<0.05, **p<0.01). E. Flow cytometry analysis was performed to detect cell cycle of HCT116 and KM12C cells pre-treated with PCMV, Flag-ZFP91 or HA-HIF-1α together with control siRNA or HIF-1α siRNA under normoxic conditions.