However, comparison of the luciferase activity of these transfected prostate cancer cell lines and those with endogenous osteonectin RNA expression (Fig 1A) revealed that hON-522E promoter activity is relatively higher in AR-negative, more aggressive, and metastatic cell lines, including DU145, PC3 and PC3M cells as compared to AR-expressing LNCaP, C4-2 and C4-2B cell lines (Fig 2C). This evidence concerns the gene SPARC and prostate cancer.