       Document 3322
 DOCN  M94A3322
 TI    Inhibitory mechanism of camptothecin on HIV-1 replication.
 DT    9412
 AU    Takahashi H; Kojima A; Kurata T; Dep. of Pathology, National Institute
       of Health, Tokyo, Japan.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):102 (abstract no. PA0028). Unique
       Identifier : AIDSLINE ICA10/94369253
 AB    OBJECTIVES--Camptothecin (CPT), a topoisomerase I inhibitor was reported
       to block retroviral infection in vitro and in vivo. CPT is also known as
       an antitumor drug and is toxic to eukaryotic cells. As HIV-1 replicates
       very poorly in non-dividing cells, CPT inhibits HIV possibly by
       suppressing cell growth, otherwise it may attack virion directly. Our
       object is to know inhibitory effects of CPT on HIV and to understand a
       role of topoisomerase I on HIV-1 replication. METHODS--HIV-1 viruses
       were treated with CPT for 1-2 hours. The pretreated viruses were
       infected to MT4 cells in the presence or absence of CPT. HIV-1
       replication was measured by p24 ELISA and RT assays. RESULTS AND
       DISCUSSION--Pretreatment of HIV-1 with CPT inhibited viral replication
       in a dose-dependent fashion. Presence of CPT during infection showed
       higher blocking of HIV-1 replication. Reduction of topoisomerase I
       activity in infected MT-4 cells by CPT was associated with decrease of
       HIV-1 infectivity. These results suggested that both virion-associated
       and cellular topoisomerase I play a regulatory role of HIV-1
       replication.
 DE    Camptothecin/*PHARMACOLOGY  Cell Division/DRUG EFFECTS  Cell Line  DNA
       Topoisomerase/ANTAGONISTS & INHIB/PHYSIOLOGY  Human  HIV Core Protein
       p24/BIOSYNTHESIS  HIV-1/*DRUG EFFECTS/ENZYMOLOGY/PHYSIOLOGY  In Vitro
       Reverse Transcriptase/BIOSYNTHESIS  Virus Replication/*DRUG
       EFFECTS/PHYSIOLOGY  MEETING ABSTRACT

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

