Figure 4.

Effects of HIF-1α siRNA on morphology and invasion in MiaPaCa2 cells treated with CoCl₂. (A) The morphology of cells was detected by hematoxylin and eosin staining and observed from five randomly selected microscopic visual fields (magnification, ×200) following treatment with or without CoCl₂ for 24 h in the presence or absence of HIF-1α siRNA. (B) Cell invasion was detected in MiaPaCa2 cells following treatment with or without CoCl₂ for 24 h in the presence or absence of HIF-1α siRNA. Invaded cells were stained with crystal violet and observed from five randomly selected microscopic visual fields (magnification, ×200). (C) Number of invaded cells were counted and expressed as cell invasion rate (%) compared with those untreated cells without CoCl₂ or HIF-1α siRNA. Data were representative of three independent experiments and expressed as the mean ± standard error of the mean. **P<0.01, ***P<0.001. HIF-1α, hypoxia inducible factor-1α; si, small interfering; NC, negative control; CoCl₂, cobalt II chloride.