Cellular uptake of neutral phosphorodiamidate morpholino oligomers.

Journal Article (Journal Article)

Phosphorodiamidate morpholino oligomers (PMO), which have a neutral chemistry, are extensively being used as tools for selective inhibition of gene expression in cell culture models and are currently in human clinical trials. Unlike phosphorothioates (PS ODN) and other charged oligonucleotides, little is known about the uptake characteristics of neutral oligomers. The purpose of this study was to understand the kinetics of PMO transport in cells and correlate with antisense activity. In contrast to primary cells and some transformed cell lines which were uptake permissive, established cancer cell lines showed very poor uptake with an occasional diffuse intracellular pattern. Differential PMO uptake was also observed in immune cells, with dendritic cells and monocytes showing highest uptake compared to T and B cells. In addition, PMO localization was observed to be heterogeneous within a population of uptake permissive cells. Unassisted PMO delivery targeting specific genes was correlated with functional antisense efficacy in experiments showing correction of pre-mRNA missplicing and inhibition of target enzyme activity in cells in culture. PMO internalization in uptake-permissive cells was identified to be specific, saturable, and energy-dependent, suggesting a receptor mediated uptake mechanism. Understanding PMO transport should facilitate the design of more effective synthetic antisense oligomers as therapeutic agents.

Full Text

Duke Authors

Cited Authors

  • Iversen, PL; Aird, KM; Wu, R; Morse, MM; Devi, GR

Published Date

  • September 2009

Published In

Volume / Issue

  • 10 / 6

Start / End Page

  • 579 - 588

PubMed ID

  • 19619124

Electronic International Standard Serial Number (EISSN)

  • 1873-4316

Digital Object Identifier (DOI)

  • 10.2174/138920109789069279


  • eng

Conference Location

  • Netherlands