LNCaP cells were obtained from ATCC. C4-2 cells and C4-2b were obtained from MD Anderson Cancer Center, Houston, TX. LNCaP-Bic cells were a kind gift from Dr Zoran Culig (General Hospital Feldkirch). DuCaP cells were a kind gift from Philips Research (Eindhoven, The Netherlands). SKOv3 cells were a kind gift from Dr. James Brenton (University of Cambridge). LNCaP, C4-2, C4-2b and DuCaP cells were maintained at 37°C in RPMI 1640 (Invitrogen) containing L-Glutamine and supplemented with 10 % fetal bovine serum (Fbs) (Gibco) in a humidified atmosphere supplied with 5 % CO2. LNCaP-Bic cells were cultured under the same conditions but medium was supplemented with 1 μM Bicalutamide (Enzo Life Science). Cells were routinely sub-cultured 1:4 using 0.25 % Trypsin-EDTA (Invitrogen) when 80-90 % confluency was reached.
Forskolin was obtained from Sigma-Aldrich. A SIK2 inhibitor, ARN3236, was obtained from Arrien Pharmaceuticals with reported low nanomolar IC50 for SIK2 both in activity assays and cell-line experiments. [22 ] SIK2 siRNA sequences were obtained from Dharmacon. [19 (link)] The non-targeting siRNA was obtained from Dharmacon. The pCMV6-Entry-myc/flag construct was obtained from Origene. The pCMV6-Entry-WT-SIK2 -myc/flag and pCMV6-Entry-SIK2-EOS-KI-myc/flag were generated as previously described. [19 (link)]