Endogenous Bone Morphogenetic Protein-7 Controls the Motility of Prostate Cancer Cells Through Regulation of Bone Morphogenetic Protein Antagonists.

Purpose: We investigated the effect of manipulating endogenous BMP-7 expression on the invasion and motility of prostate cancer cells and the resulting effect on its antagonists using a ribozyme transgene. Materials and Methods: A hammerhead ribozyme transgene was synthesized and cloned into a mammalian expression vector (pcDNA3.1/nt-GFP-TOPO). PC-3 cells (American Type Culture Collection, Manassas, Virginia) were transfected with the ribozyme transgene (PC-3 ^ΔBMP7) or with an empty plasmid (PC-3^pcDNA/GFP) by electroporation. Invasion and motility were accessed by in vitro invasion and motility assays. Results: The ribozyme decreased BMP-7 expression at the mRNA and protein levels in PC-3 cells. Invasive potential was significantly increased following the loss of BMP-7 expression. The mean ± SD invading cell number for PC-3 ^ΔBMP7 was 231.3 ± 28.6 vs 7.1 ± 4.4 for the WT cell line PC-3^WT and 2.7 ± 2 for PC-3^pcDNA/GFP (each p <0.001). BMP-7 knockdown in PC-3 cells significantly increased motility with a migrating cell number for PC-3 ^ΔBMP7 of 24 ± 7.5 compared with 10.2 ± 4.5 for PC-3^WT and 11.3 ± 7.5 for PC-3^pcDNA/GFP (p <0.01 and 0.011, respectively). The change in motility was seen together with changes in the cellular location of paxillin and focal adhesion kinase (p125^FAK). Interestingly the loss of BMP-7 resulted in decreased noggin and follistatin expression. Conclusions: The loss of endogenous BMP-7 from prostate cancer cells is associated with increased invasiveness and motility, which appears to be facilitated by changes in the level of the BMP antagonists noggin and follistatin. Endogenous BMP-7 has an important role in controlling noggin and follistatin expression. [Copyright &y& Elsevier]