Examination of CXCR4 expression in prostate cancer cell lines expressing SLUG shRNAs. (A, B) Analysis of CXCR4 RNA transcripts by qPCR (left panel) and RT-PCR (right panel). RNA was extracted from PC3 and DU-145 prostate cancer cell lines stably expressing Slug shRNA (Sh1, Sh2) or shRNA control (ShRNA Ctr). All RNA was extracted from these cells four days after infection, and subjected to cDNA synthesis. The CXCR4 and SLUG transcripts were analyzed by qPCR or RT-PCR, or both. GAPDH was included as a control. CXCR4 was significantly downregulated in human prostate cancer cell lines harboring Slug-specific shRNAs. (C) Western Blot analysis of CXCR4 protein level in PC3 (left panel) and DU-145 (right panel) lines stably carrying Slug shRNA or control. All protein was extracted and analyzed by Western blot analysis using anti-Slug, anti-CXCR4, anti-gapdh antibodies (loading control).