Methylation of the CD133 promoter in prostate primary tissues and xenografts. Methylation analysis of the CD133 promoter in primary prostate cancer xenografts generated in RAG2-/- gamma C-/- mice (A), in PC3 xenografts (D) and in prostate tissues (DNA extracted from glass slides of pooled snap frozen tissue sections) (E) and by pyrosequencing (PYRO 1 assay; bars = single CpG sites; n = 3 technical replicas; ± SD; black line = average of 10 CpG sites; * = p < 0.05; ** = p < 0.01; *** = p < 0.001 in an unpaired t-test). (B) Representative image of CD133 expression measured by FACs in disaggregated primary prostate cancer xenografts. X axes: FITC channel fluorescence (not stained); Y axes: APC channel fluorescence (CD133-APC); Percent of CD133+ cells is indicated. (D) qRT-PCR analysis (relative to RPLP0, calibrator = PC3; N.D. = expression undetectable after 40 cycles) of CD133 expression in PC3 xenografts compared to PC3 (RC-165N/hTERT was used as a positive control).