Fig. 9.
Hypoxia up-regulates the CXCR4 expression in the PLC/PRF5 cells. To induce hypoxia, the cells were incubated in serum-free X-VIVO medium at 1% O2 for 16 h. (A) The cell surface expression of CXCR4 in the five liver cancer cell lines that were subjected to normoxia and hypoxia. (B) The cell surface expression of CXCR4 was enhanced in the PLC/PRF5 cells by hypoxic incubation. (a) Isotype control. (b) Normoxia. (c) Hypoxia. (C) The Western blotting showed the induction of the HIF-1α expression by hypoxia in the PLC/PRF5 cells. (D) Flow cytometric analysis after permeabilization revealed that hypoxia enhanced the cytoplasmic expression of CXCR4. (E) Hypoxia induced the transmigration of PLC/PRF5 cells in response to SDF-1. The data is given as the mean±S.D. of the migration index from three independent experiments. *p<0.05.