Figure 4

HXR9 induced apoptosis is mediated by cFos . (a) QPCR analysis of cFos expression in response to treatment of PC3, DU145, LNCaP and WPMY-1 cells with 60 μM HXR9 or CXR9 for two hours. ‘Unt’ – untreated cells; cFos expression is shown as a ratio with the β-actin gene (×10,000). (b) Knock down of cFos expression using siRNA. DU145 cells were incubated with transfection reagent alone (‘Transf only’), or were transfected with a control siRNA with a random sequence (‘rnd siRNA’), or with one of two siRNA targeting cFos (‘cFos siRNA 1’ and ‘cFos siRNA 2’). Cells were also either treated with 60 μM HXR9 or CXR9, or with HXR9 in combination with one of the transfected cFos specific siRNAs (‘HXR9 + s1’ or ‘HXR9 + s2’). The expression of cFos in treated cells was determined either at the RNA level using QPCR (upper section) or at the protein level using western blotting (lower section). (c) The % cell survival for each of the treatments described in (b). Knock down of cFos in HXR9 treated cells results in a statistically significant decrease in cell death. Error bars show the SEM. *p < 0.05, ***p < 0.001 with respect to untreated cells.