Using the Oncomine database we investigated changes in e pression patterns for these methylated targets, and we found a significant associa tion between progression of prostate cancer and metas tasis our website with e pression of a number of genes including G protein, beta 1 subunit, retinoblastoma binding protein 8, secretogranin III and So 1. Albeit a number of these proteins have been shown to play a role in cancer, we chose to investigate the role of So 1 in our model since it is very homolo gous to the induced pluripotent stem cell regulator So 2, and has been shown to play a role in progression of lung and nasopharyngeal cancer. We also chose to investigate bone marrow tyrosine kinase gene in chromosome protein since it has been shown to regulate hematopoiesis and play a role in the regulation of prostate cancer.

However, from our Oncomine analysis Bm was not shown to signifi cantly affect prostate cancer metastasis. Verification of methylation array data To verify the results from our methylation specific pro moter tiling arrays, we performed methylation specific PCR where primers were designed around the probe sequences identified from the arrays. Both Bm and So 1 were found to be methylated in the parental LNCaP and DU145 cell lines, representing the non invasive phenotype. To deter mine if this pattern of methylation correlated with the level of gene e pression, real time quantitative PCR was performed. Significant differences in the e pression of Bm and So 1 were seen when comparing the e pression in non invasive and invasive cell popula tions in both LNCaP and DU145 cell lines.

To further validate the results, immunocytochemistry was performed to analyze differences in protein e pres sion between non invasive and invasive cells. There is significantly higher e pression of activated BM and SO 1 in the invasive versus non invasive cells. Therefore, we validated the methylation and resul tant decreased e pression of BM and SO 1 in the non invasive cells. Functional role of Bm and So 1 during invasion To further determine the role of Brefeldin_A Bm and So 1 during the process of invasion we performed the invasion assay with DU145 cells stably infected with shRNAs directed against So 1or Bm . A significant decrease in e pression of SO 1 and BM following induction with 1 ug mL of do ycycline for 24 hours was first verified using western blotting. Upon induction with Do , the shRNA is turned on and a downstream red fluorescent protein demonstrates efficiency of this induction. Densitometry analysis was per formed to compare e pression of individual clones with the NS cells, and no significant differences in protein e pression were seen using the non silencing con trols.