简介：Theeventsofcelldeathandtheexpressionofnuclearmatrixprotein(NMP)havebeeninvestigatedinapromyelocyticleukemiccelllineHL-60inducedwithetoposide.BymeansofTUNELassay,thenucleidisplayedacharacteristicmorphologychange,andtheamountofapoptoticcellsincreasedearlyandreachedmaximunabout39%aftertreatmentwithetoposidefor2h.NucleosomalDNAfragmentationwasobservedaftertreatmentfor4h.ThemorphologicalchangeofHL-60cells,thus,occurredearlierthantheappearanceofDNAladder.Totalnuclearmatrixproteinswereanalyzedby2-dimensionalgelelectrophoresis.Differentialexpressionof59nuclearmatrixproteinswasfoundin4hetoposidetreatedcells.Westernblottingwasthenperformedonthreenuclearmatrixacssociatedproteins,PML,HSC70andNuMA.TheexpressionofthesuppressorPMLproteinandheatshockproteinHSC70weresignificantlyupregulatedafteretoposidetreatment,whileNuMA,anuclearmitoticapparatusprotein,wasdownregulated.Theseresultsdemonstratethatsignificantbiochemicalalterationsinnuclearmatrixproteinstakeplaceduringtheapoptoticprocess.