Protein tyrosine phosphatase receptor-type O (PTPRO) is co-regulated by E2F1 and miR-17-92

PTPRO is often silenced by DNA hypermethylation in primary human tumors and cancer cell lines and functions as a tumor suppressor. Here we show that PTPRO is a target of E2F1. In addition, the microRNA cluster miR-17-92, another target of E2F1, participates in PTPRO regulation. PTPRO mRNA was up-regulated during S phase in synchronized HeLa cells and in vitro PTPRO promoter activity is high in early S phase while the PTPRO 3′UTR reporter activity is low in late S phase. This study provides evidence that the PTPRO gene is co-regulated by both E2F1 and miR-17-92.