Figure 5
Blocking the lipid synthesis pathways suppresses tumor growth in the CWR22-RV1-derived CRPC xenograft model. (a) Immunofluorescence staining for cholesterol (blue) in CWR22-RV1 cells treated with DHT (10nM) for 1d, 2d and cholesterol trafficking inhibitor U-18666 A (1 μM) for 1d (positive control). Nuclear compartment was determined by SYBR green staining (green). (b, c) CWR22-RV1 cells were treated with DHT alone and/or statin (10 μM, pretreat 4 h), followed by (b) qRT-PCR for indicated genes and (c) immunoblotting for Ser244-phosphorylated S6 and AR (using antibody against N-terminus of AR). (d, e) CWR22-RV1 cells were treated with statin and/or DHT, followed by flow cytometry cell counting of (d) live cells and (e) caspase-3/7 activity-high cells. (f–h) Castrated SCID mice (age ~6 weeks) bearing CWR22-RV1 xenograft tumors (N=5) were treated with vehicle or statin (10 mg/kg daily), followed by (f) measuring tumor volume, (g) qRT-PCR analysis for mRNA expression from biopsies collected at day 15, and (h) immunoblotting for p-S6 in those samples. The statistical analysis was done using student’s t-test and the sample size was estimated based on power analysis. The animals were randomized into two experimental groups and blinding was done for tumor measurement.
