MMP9 and CXCL12 expression in prostate cancer cells expressing shRNAs targeting SLUG or CXCL12 mRNA. (A, B) qPCR (left panel) and RT-PCR (right panel) analysis of MMP9 RNA transcripts in prostate cancer cell lines harboring SLUG shRNAs. RNA was extracted from PC3 and DU145 cell lines stably expressing SLUG shRNA (Sh1, Sh2) or control shRNA (Ctr), and subjected to cDNA synthesis. Transcript level of MMP9 in these cell lines was analyzed by qPCR (left panel) and RT-PCR (right panel). GAPDH was included as a control. MMP9 was significantly downregulated in PC3 and DU145 cell lines carrying Slug shRNAs. (C) Identification of CXCL12-specific shRNAs. PC3-pMig and PC3-pMig-Slug stable cells lines were infected with lentiviruses expressing control shRNA (sh Ctr) and CXCL12 shRNAs (Sh1, Sh2), and followed by puromycin selection. Total RNA was extracted from these stable cell lines and CXCL12 expression was analyzed by RT-PCR.