FIGURE 7.

SRC-1 cooperates with SRC-3 to promote HCC cell proliferation. A, PCNA protein levels were increased in SRC-1(+)/SRC-3(−), SRC-1(−)/SRC-3(+), and SRC-1(+)/SRC-3(+) HCC specimens compared with SRC-1(−)/SRC-3(−) HCC specimens. B, simultaneous down-regulation of SRC-1 and SRC-3 led to a more significant reduction in cell proliferation than down-regulation of SRC-1 or SRC-3 alone. HepG2 cells were transfected with siRNAs specific for SRC-1 and/or SRC-3 for 48 h and seeded into 96-well plates for MTT assays. This experiment was performed three times with similar results. C, c-Myc protein levels were further decreased after simultaneous knockdown of SRC-1 and SRC-3. This experiment was performed three times with similar results. D, bufalin treatment for 24 h dramatically reduced the protein levels of SRC-1, SRC-3, and c-Myc in HepG2 and SK-Hep-1 cells. HepG2 and SK-Hep-1 cells were treated with 10 or 20 nm bufalin for 24 h, and cells were lysed for Western blot analysis. This experiment was performed twice with similar results. E, bufalin treatment significantly inhibited proliferation in HepG2 and SK-Hep-1 cells. A total of 3000 cells were seeded into 96-well plates and treated with 10 or 20 nm bufalin for the indicated time before MTT was added. This experiment was performed twice with similar results. *, p < 0.05; **, p < 0.01. Error bars, S.E.