简介：Peptidenucleicacids(PNAs)aresyntheticoligonucleotideswithchemicallymodifiedbackbones.PNAscanbindtobothDNAandRNAtargetsinasequence-specificmannertoformPNA/DNAandPNA/RNAduplexstructures.Whenboundtodouble-strandedDNA(dsDNA)targets,thePNAmoleculereplacesoneDNAstrandintheduplexbystrandinvasiontoformaPNA/DNA/PNA[or(PNA)2/DNA]triplexstructureandthedisplacedDNAstrandexistsasasinglestrandedD-loop.PNAhasbeenusedinmanystudiesasresearchtoolsforgeneregulationandgenetargeting.TheDloopsgeneratedfromthePNAbindinghavealsobeendemonstratedforitspotentialininitiatingtranscriptionandinducinggeneexpression.PNAprovidesapowerfultooltostudythemechanismoftranscriptionandaninnovativestrategytoregulatetargetgeneexpression.AnunderstandingofthePNA-mediatedgeneregulationwillhaveimportantclinicalimplicationsintreatmentofmanyhumandiseasesincludinggenetic,cancerous,andage-relateddiseases.