Multiple centrosome formation induced by the expression of Vpr gene of human immunodeficiency virus

We previously established a cell line called MIT-23 in which expression of the Vpr gene of human immunodeficiency virus 1 (HIV-1) can be controlled by the addition of tetracycline. Vpr expression induces multiple nuclear form ation and increased ploidy in MIT-23 cells, We herein report that multipola r mitotic spindles were formed upon induction of Vpr. Further analysis of c entrosomes with anti-gamma-tubulin immunostaining revealed that a significa nt population of cells 1 week after expression of Vpr gene product had an i ncreased number of centrosomes in the cells with abnormal nuclei. Taking in to account that the centrosome plays an important role in genome integrity, the abnormal number of centrosomes in cells expressing Vpr may be directly related to aneuploidy or the formation of micronuclei in MIT-23 cells, sug gesting that Vpr has an oncogenic role in HIV infected cells. (C) 1999 Acad emic Press.