Figure 4.

PKM2 upregulates HIF-1α via Erk and is important in regulating proliferation of arsenic-transformed cells. (A) Arsenic transformed cells were transfected with vectors expressing NC, PKM2 or siPKM2, and 60 h later, PKM2 and HIF-1α expression was tracked using Western blotting. (B) As-T cells were co-transfected with an HIF-1α promoter reporter (containing PKM2 binding sites) and PKM2. After 6 h, the cells were cultured with an ERK1/2 inhibitor or HB-EGF, as indicated, and luciferase (Luc) activities were determined. (C) The CCK-8 assay monitored proliferation of As-T cells transfected with an HIF-1α expression vector or a control, according to the manufacturer's instruction. Proliferation rates were determined daily for 4 days after seeding. (D) As-T cells were analyzed as in (C), after transfection with PKM2, ashPKM2 plasmid, or a control. (E) PKM2's effect on trans-well migration of As-T cells. Passaged cells were stained with a crystal violet solution and counted. Data are presented as the mean±SD. *p < 0.05, **^,##p < 0.01, ***^,###p < 0.001.