Characterization of oligonucleotide transport into living cells.

TLDR

Antisense oligonucleotides have been used to inhibit gene expression, and understanding their transport mechanism could improve the design of therapeutic oligomers. The study aimed to investigate how oligonucleotides enter living cells. The authors examined the cellular uptake mechanism of oligonucleotides. Oligonucleotides are taken up via a saturable, size‑dependent, receptor‑mediated endocytic pathway; polynucleotides bearing a 5′‑phosphate competitively inhibit transport, and affinity purification identified an 80‑kDa surface protein that may mediate this process.

Abstract

Addition of antisense oligonucleotides to cell cultures has been used to specifically inhibit gene expression. We have investigated the mechanism by which oligonucleotides enter living cells. These compounds are taken up by cells in a saturable, size-dependent manner compatible with receptor-mediated endocytosis. Polynucleotides of any length are competitive inhibitors of oligomer transport, providing they possess a 5'-phosphate moiety. Using oligo(dT)-cellulose for affinity purification, we have identified an 80-kDa surface protein that may mediate transport. Knowledge of the oligonucleotide transport mechanism should facilitate the design of more effective synthetic antisense oligomers as potential clinical agents.