简介：Cisplatindamagescochlearhaircellsandspiralganglionneuronsthroughcelldeathsignalingpathwaysthatarenotfullyunderstood.Weusedfocusedapoptosisgenemicroarraystostudyearlychangesingeneexpres-sionincochlearculturesfromP3neonatalratstreatedwithcisplatin(0.2mM).After12hoursofcisplatintreat-ment,morethan50%ofthe96genesonthearrayshowedasignificantdecreaseinexpression,consistentwithwidespreadcelldeath.However,after3hoursofcisplatintreatment,10genesshowedsignificantincreaseinex-pressionintotalcochleartissue.Inexperimentswithsubsetsofcochleartissues,at3h,cisplatininducedincreasedexpressionof12genesinthecochlearsensoryepithelium(basilarmembrane)and11genesinthespiralganglion(tissueofRosenthal'scanal,containingthespiralganglion).Theseincludedpro-andanti-apoptoticgenesin-volvedinthep53signalingpathway,TNFreceptorfamily,NF-kappaBpathway,deathdomainfamily,deatheffec-tordomainfamily,Bcl-2family,CARDfamily,TRAFfamily,andGTPsignaltransduction.Althoughthechangesingeneexpressionshowedanoverlapbetweenbasilarmembraneandspiralganglion,otherchanges,whichmayreflecttheuniqueresponseofeachtissue,werealsoobserved.Pifithrin-αblockedcisplatin-inducedup-regulationofgenesinthep53signalingpathwaywhenassayedbybothsuperarrayandrealtimePCR.Thedataaddtoourunderstandingoftheinvolvementofp53incisplatin-inducedototoxicityandotoprotection,conferredbythep53inhibitorPifithrin-α.