Systemic administration of optimized aptamer-siRNA chimeras promotes regression of PSMA-expressing tumors.

Published

Journal Article

Prostate cancer cells expressing prostate-specific membrane antigen (PSMA) have been targeted with RNA aptamer-small interfering (si)RNA chimeras, but therapeutic efficacy in vivo was demonstrated only with intratumoral injection. Clinical translation of this approach will require chimeras that are effective when administered systemically and are amenable to chemical synthesis. To these ends, we enhanced the silencing activity and specificity of aptamer-siRNA chimeras by incorporating modifications that enable more efficient processing of the siRNA by the cellular machinery. These included adding 2-nucleotide 3'-overhangs and optimizing the thermodynamic profile and structure of the duplex to favor processing of the siRNA guide strand. We also truncated the aptamer portion of the chimeras to facilitate large-scale chemical synthesis. The optimized chimeras resulted in pronounced regression of PSMA-expressing tumors in athymic mice after systemic administration. Anti-tumor activity was further enhanced by appending a polyethylene glycol moiety, which increased the chimeras' circulating half-life.

Full Text

Duke Authors

Cited Authors

  • Dassie, JP; Liu, X-Y; Thomas, GS; Whitaker, RM; Thiel, KW; Stockdale, KR; Meyerholz, DK; McCaffrey, AP; McNamara, JO; Giangrande, PH

Published Date

  • September 2009

Published In

Volume / Issue

  • 27 / 9

Start / End Page

  • 839 - 849

PubMed ID

  • 19701187

Pubmed Central ID

  • 19701187

Electronic International Standard Serial Number (EISSN)

  • 1546-1696

International Standard Serial Number (ISSN)

  • 1087-0156

Digital Object Identifier (DOI)

  • 10.1038/nbt.1560

Language

  • eng