Calcium ions effectively enhance the effect of antisense peptide nucleic acids conjugated to cationic tat and oligoarginine peptides

TY - JOUR

T1 - Calcium ions effectively enhance the effect of antisense peptide nucleic acids conjugated to cationic tat and oligoarginine peptides

AU - Shiraishi, Takehiko

AU - Pankratova, Stanislava

AU - Nielsen, Peter E

N1 - Keywords: Animals; Arginine; Biological Transport; Calcium; Cell Compartmentation; Endocytosis; Endosomes; Gene Expression Regulation; Gene Products, tat; Hela Cells; Humans; Oligonucleotides, Antisense; Oligopeptides; Peptide Nucleic Acids

PY - 2005

Y1 - 2005

N2 - Cell-penetrating peptides have been widely used to improve cellular delivery of a variety of proteins and antisense agents. However, recent studies indicate that such cationic peptides are predominantly entering cells via an endosomal pathway. We now show that the nuclear antisense effect in HeLa cells of a variety of peptide nucleic acid (PNA) peptide conjugates is significantly enhanced by addition of 6 mM Ca(2+) (as well as by the lysosomotrophic agent chloroquine). In particular, the antisense activities of Tat(48-60) and heptaarginine-conjugated PNAs were increased 44-fold and 8.5-fold, respectively. Evidence is presented that the mechanism involves endosomal release. The present results show that Ca(2+) can be used as an effective enhancer for in vitro cellular delivery of cationic peptide-conjugated PNA oligomers, and also emphasize the significance of the endosomal escape route for such peptides.

AB - Cell-penetrating peptides have been widely used to improve cellular delivery of a variety of proteins and antisense agents. However, recent studies indicate that such cationic peptides are predominantly entering cells via an endosomal pathway. We now show that the nuclear antisense effect in HeLa cells of a variety of peptide nucleic acid (PNA) peptide conjugates is significantly enhanced by addition of 6 mM Ca(2+) (as well as by the lysosomotrophic agent chloroquine). In particular, the antisense activities of Tat(48-60) and heptaarginine-conjugated PNAs were increased 44-fold and 8.5-fold, respectively. Evidence is presented that the mechanism involves endosomal release. The present results show that Ca(2+) can be used as an effective enhancer for in vitro cellular delivery of cationic peptide-conjugated PNA oligomers, and also emphasize the significance of the endosomal escape route for such peptides.

U2 - 10.1016/j.chembiol.2005.06.009

DO - 10.1016/j.chembiol.2005.06.009

M3 - Journal article

C2 - 16125104

SN - 1074-5521

VL - 12

SP - 923

EP - 929

JO - Chemistry & Biology

JF - Chemistry & Biology

IS - 8

ER -