title: 9-Aminoacridine inhibition of HIV-1 Tat dependent transcription.
abstract: As part of a continued search for more efficient anti-HIV-1 drugs, we are focusing on the possibility that small molecules could efficiently inhibit HIV-1 replication through the restoration of p53 and p21WAF1 functions, which are inactivated by HIV-1 infection. Here we describe the molecular mechanism of 9-aminoacridine (9AA) mediated HIV-1 inhibition. 9AA treatment resulted in inhibition of HIV LTR transcription in a specific manner that was highly dependent on the presence and location of the amino moiety. Importantly, virus replication was found to be inhibited in HIV-1 infected cell lines by 9AA in a dose-dependent manner without inhibiting cellular proliferation or inducing cell death. 9AA inhibited viral replication in both p53 wildtype and p53 mutant cells, indicating that there is another p53 independent factor that was critical for HIV inhibition. p21WAF1 is an ideal candidate as p21WAF1 levels were increased in both p53 wildtype and p53 mutant cells, and p21WAF1 was found to be phosphorylated at S146, an event previously shown to increase its stability. Furthermore, we observed p21WAF1 in complex with cyclin T1 and cdk9 in vitro, suggesting a direct role of p21WAF1 in HIV transcription inhibition. Finally, 9AA treatment resulted in loss of cdk9 from the viral promoter, providing one possible mechanism of transcriptional inhibition. Thus, 9AA treatment was highly efficient at reactivating the p53 - p21WAF1 pathway and consequently inhibiting HIV replication and transcription.
authors.affiliation: Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC 20037, USA.mtmixg@gwumc.edu
authors.forename: Irene
authors.initials: I
authors.lastname: Guendel
authors.forename: Lawrence
authors.initials: L
authors.lastname: Carpio
authors.forename: Rebecca
authors.initials: R
authors.lastname: Easley
authors.forename: Rachel
authors.initials: R
authors.lastname: Van Duyne
authors.forename: William
authors.initials: W
authors.lastname: Coley
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Agbottah
authors.forename: Cynthia
authors.initials: C
authors.lastname: Dowd
authors.forename: Fatah
authors.initials: F
authors.lastname: Kashanchi
authors.forename: Kylene
authors.initials: K
authors.lastname: Kehn-Hall
mesh_terms: D000585:Aminacrine / Q000494:pharmacology*; D019380:Anti-HIV Agents / Q000494:pharmacology*; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000502:physiology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D013601:T-Lymphocytes / Q000187:drug effects / Q000821:virology; D014158:Transcription, Genetic / Q000187:drug effects*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D014779:Virus Replication / Q000187:drug effects; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors*
chemical_list: D019380:Anti-HIV Agents; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53; D054322:tat Gene Products, Human Immunodeficiency Virus; D000585:Aminacrine