22Rv1 cells (2×106) were injected sub-cutaneously into both flanks of SCID mice and tumor growth was monitored. Once the tumors were palpable, the mice were randomly divided into 4 groups (n=6/group) and treated with: 1) vehicle (0.5% Methocel 4AM), 2) 25 mg/kg enzalutamide via oral gavage daily for 5 days/week, 3) 20 mg/kg quercetin i.p. daily for 5 days/week, and 4) a combination of quercetin and enzalutamide daily for 5 days/week. Tumors (n=12/group) were monitored twice a week and were harvested and weighed at the end of 3 weeks. Tumor volumes (A) and weights (B) of tumors treated with the combination of quercetin and enzalutamide were significantly reduced. C) Total RNAs derived from the tumor tissues were analyzed by qRT-PCR for the expression levels of hnRNPA1, FL AR, and AR-V7. Transcript levels of hnRNPA1, FL AR, and AR-V7 were reduced significantly in the tumor tissues by treatment with the combination of quercetin and enzalutamide. * denotes p ≤0.05.