Fig. 8

KH-3 inhibits BCAT1 expression and attenuates CRPC cell progression in vitro and in vivo. A RIP qRT-PCR analysis showed that the binding of HuR to BCAT1 mRNA was affected by KH-3 (10 μM) in PC3 and DU145 cells. Isotype IgG was used as a negative control for the HuR antibody. B Representative immunoblots showing ERK5, p-ERK5, HuR, and BCAT1 expression in PC3 and DU145 cells incubated with KH-3 (10 μM) for 24 h (left). The right show the expression intensity normalized to that of β-tubulin. C–E PC3 and DU145 cells were treated with KH-3 (10 μM) as above, after which proliferation (C), colony formation (D), migration, and invasion (E) were measured. The right show the quantitative results. F The volume of tumour xenografts in nude mice inoculated with PC3 cells an intraperitoneally injected with 70 mg/kg KH-3 twice per week starting from the first day after tumours grew to an approximate diameter of 4 mm and continuing to the third week (n = 3). G After 21 days, the mice were sacrificed, and the size (left panel) and weight (right panel) of the tumour xenografts in nude mice were measured (n = 3). H Representative immunostaining (scale bar: 50 μm) of Ki67 and BCAT1 expression in tumour xenografts in nude mice inoculated with PC3 cells and treated with KH-3 at 21 days. The dashed square outlines the higher magnification image. The right show the percentages of Ki67- and BCAT1-positive areas (brown) (n = 3). p values are shown for each comparison (^**p < 0.01, ^##p < 0.01)