title: Effective inhibition of Rta expression and lytic replication of Kaposi's sarcoma-associated herpesvirus by human RNase P.
abstract: Ribonuclease P (RNase P) complexed with external guide sequence (EGS) represents a nucleic acid-based gene interference approach to knock-down gene expression. Unlike other strategies, such as antisense oligonucleotides, ribozymes, and RNA interference, the RNase P-based technology is unique because a custom-designed EGS molecule can bind to any complementary mRNA sequence and recruit intracellular RNase P for specific degradation of the target mRNA. In this study, we demonstrate that the RNase P-based strategy is effective in blocking gene expression and growth of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), the causative agent of the leading AIDS-associated neoplasms, such as KS and primary-effusion lymphoma. We constructed 2'-O-methyl-modified EGS molecules that target the mRNA encoding KSHV immediate-early transcription activator Rta, and we administered them directly to human primary-effusion lymphoma cells infected with KSHV. A reduction of 90% in Rta expression and a reduction of approximately 150-fold in viral growth were observed in cells treated with a functional EGS. In contrast, a reduction of <10% in the Rta expression and viral growth was found in cells that were either not treated with an EGS or that were treated with a disabled EGS containing mutations that preclude recognition by RNase P. Our study provides direct evidence that EGSs are highly effective in inhibiting KSHV gene expression and growth. Exogenous administration of chemically modified EGSs in inducing RNase P-mediated cleavage represents an approach for inhibiting specific gene expression and for treating human diseases, including KSHV-associated tumors.
authors.affiliation: Program in Infectious Diseases, School of Public Health, 140 Warren Hall, University of California, Berkeley, CA 94720, USA.
authors.forename: Jiaming
authors.initials: J
authors.lastname: Zhu
authors.forename: Phong
authors.initials: P
authors.lastname: Trang
authors.forename: Kihoon
authors.initials: K
authors.lastname: Kim
authors.forename: Tianhong
authors.initials: T
authors.lastname: Zhou
authors.forename: Hongyu
authors.initials: H
authors.lastname: Deng
authors.forename: Fenyong
authors.initials: F
authors.lastname: Liu
mesh_terms: D000998:Antiviral Agents / Q000378:metabolism / Q000494:pharmacology; D001483:Base Sequence; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D006367:HeLa Cells; D019288:Herpesvirus 8, Human / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008223:Lymphoma / Q000821:virology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D043262:Ribonuclease P / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D002457:Cell Extracts; D004279:DNA, Viral; C116742:ORF 50 transactivator; D012333:RNA, Messenger; D015534:Trans-Activators; D014764:Viral Proteins; D043262:Ribonuclease P