HIV-1 viral protein R downregulates Ebp1 and stabilizes p53 in glioblastoma U87MG cells

HIV-1 viral protein R (Vpr) inhibits cell growth and induces apoptosis in a wide range of cancers. However, the mechanism by which Vpr induces cell cycle arrest and apoptosis in GBM cell lines is unclear. The present work was taken to detect the proteins interacted with Vpr in U87MG cells. We analyzed the differential expression of proteins between glioblastoma cell U87MG treated with Ad-Vpr and untreated by 2-DE. We used antibody array analysis to analyze the common molecules in the apoptosis of U87MG induced by Vpr. We analyzed the differential expression of proteins between U87MG cell treated with Ad-Vpr and untreated, and found that proteins related to DNA damage repair or different apoptosis pathways were involved in the G(2) arrest and apoptosis mediated by Vpr. In addition, proliferation-associated protein 2G4 (PA2G4), also known as Ebp1, was down-regulated and p53 was up-regulated in U87MG cells treated with Ad-Vpr. Our data suggest that Vpr may inhibit Ebp1 to stabilize p53, which in turn leads to G(2) arrest and apoptosis in U87MG cells.