Figure 2. Generation-2.5 ASO targeting mouse Ar decreases expression of full-length AR and putative splice variants.

Expression of full-length AR (AR-FL) and aberrant AR in mouse prostate tumors was determined by automated capillary electrophoresis with an AR antibody targeting the n-terminal domain (AR-NTD, aa204-221) and the ligand binding domain (AR-LBD, aa660-899, see Supplemental Figure 3C) in prostates from 20-week-old normal WT (Pten^+/+) mice or prostate tumors from untreated and ISIS581088-treated Pten-deficient (Pten^–/–) mice. ISI581088 was administered for 4 weeks (40 mg/kg/d for first week loading, followed by 3 weeks of maintenance dosing, 40 mg/kg 3×/week). The results are shown as a virtual blot (A) and electropherogram (B). AR-FL, putative AR-Vs and high molecular weight bands are represented by blue, red, and black arrows, respectively. Shaded areas in the electropherogram denote peaks after baseline correction. (C) Western blot of AR expression using anti–AR-NTD and anti–AR-LBD antibodies in prostate tumors from untreated Pten-KO mice and 14 days after orchidectomy or 10 days of treatment with ISIS581088 (ISIS581088 was administered according to the dosing schedule in Supplemental Figure 1A). GAPDH was used a loading control. (D) Plots of Ar mRNA expression by qPCR. Horizontal bars represent mean ± SEM, and diamonds represent individual samples; n = 3 mice/group. Significance represent Student-Newman-Keuls post hoc test for individual comparisons, upon significant 1-way ANOVA (Ar Ex2, F_2,8 = 65.306, P < 0.001; Ar Ex7, F_2,8 = 46.706, P < 0.001).