This study examined the efficiency of human immunodeficiency virus type 1 (HIV-1) integration in poly(ADP-ribose)polymerase-1 (PARP-1)-deficient murine cells and in human cell lines transfected with small interfering RNA against PARP-1 (PARP-1 siRNA). To semi-quantify the amount of integrated HIV-1 genome, real-time nested PCR was carried out using primers specific for Alu and alphoid DNA combined with primers for the HIV-1 genome. The results showed that the integration efficiency of the HIV-1 genome near Alu DNA, which is randomly distributed in the chromosome, is reduced in PARP-1-deficient murine cells, but not in PARP-1 siRNA-transfected human cells. By contrast, the integration efficiency of the HIV-1 gnome near alphoid DNA, which is localized in the centromere region, is significantly reduced in PARP-1-deficient murine cells and in PARP-1 siRNA-transfected human cells. These results suggest that PARP-1 is required for HIV-1 integration near the centromere region both in human and murine cells. (c) 2005 Elsevier Inc. All rights reserved.