Figure 2.

The effects of PCSK9 on cell proliferation, cell cycle phase distribution and apoptosis. (A) PCSK9 overexpression in 97H cells and successful knockdown of PCSK9 in HepG2 cells were confirmed by Western blot and qRT-PCR. (B) The proliferations of 97H and HepG2 cells were significantly changed after knockdown and overexpression of PCSK9, respectively. (C) Representative results of cell cycle analysis by flow cytometry after propidium iodide (PI) staining. (D) Representative results of apoptosis analysis by flow cytometry after dual staining with annexin V and PI. (E) Western blot analysis shows the levels of a proliferation marker (proliferating cell nuclear antigen), apoptosis markers (Bcl-2, Bax, Bid, and cleaved caspase-3) and cell cycle proteins (cyclin D1, cyclin D3, and CDK4). The data are expressed as the mean ± SD of 3 independent experiments, each performed in triplicate; *P < 0.05, **P < 0.01.