title: A study of the topoisomerase II activity in HIV-1 replication using the ferrocene derivatives as probes.
abstract: Human Topoisomerase II is present in two isoforms, 170KDa alpha and 180KDa beta. Both the isoforms play a crucial role in maintenance of topological changes during DNA replication and recombination. It has been shown that Topoisomerase II activity is required for HIV-1 replication and the enzyme is phosphorylated during early time points of HIV-1 replication. In the present study, we have studied the molecular action of Topoisomerase II inhibitors, azalactone ferrocene (AzaFecp), Thiomorpholide amido methyl ferrocene (ThioFecp), and Ruthenium benzene amino pyridine (Ru(ben)Apy) on cell proliferation and also on various events of HIV-1 replication cycle. The Topoisomerase II beta over-expressing neuroblastoma cell line shows a higher sensitivity to these compounds compared to the Sup-T1 cell line. All the three Topoisomerase II inhibitors show significant anti-HIV activity at nanomolar concentrations against an Indian isolate of HIV-1(93IN101) in Sup-T1 cell line. An analysis of action of these compounds on proviral DNA synthesis at 5h of post-infection shows that they inhibit proviral DNA synthesis as well as the formation of pre-integration complexes completely. Further analysis, using polymerase chain reaction and western blot, showed that both the Topoisomerase II alpha and beta isoforms are present in the pre-integration complexes, suggesting their significant role in HIV-1 replication.
authors.affiliation: Department of Biochemistry, University of Hyderabad, School of Life Sciences, Hyderabad 500 046, India. akksl@uohyd.ernet.in
authors.forename: Anand K
authors.initials: AK
authors.lastname: Kondapi
authors.forename: Nathamu
authors.initials: N
authors.lastname: Satyanarayana
authors.forename: A D
authors.initials: AD
authors.lastname: Saikrishna
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005296:Ferrous Compounds / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D000075163:Metallocenes; D009025:Morpholines / Q000494:pharmacology; D009942:Organometallic Compounds / Q000494:pharmacology; D010080:Oxazoles / Q000494:pharmacology; D010766:Phosphorylation; D011533:Proviruses / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D059005:Topoisomerase II Inhibitors; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000951:Antigens, Neoplasm; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D005296:Ferrous Compounds; D007527:Isoenzymes; D000075163:Metallocenes; D009025:Morpholines; D009942:Organometallic Compounds; D010080:Oxazoles; D059005:Topoisomerase II Inhibitors; C502556:azalactone ferrocene; C502555:thiomorpholide amido methyl ferrocene; D004250:DNA Topoisomerases, Type II