Objectiveandbackground:Althoughp21rashasbeenreportedtobeupregulatedinhepatocellularcarcinomacomplicatingchronichepatitisCtypeI,p21rashasadifferentroleinadvancedstages,asithasbeenfoundtobedownregulated.Thegoalofthisstudywastoinvestigatethestatusofp21rasinearly-stage/low-gradeandlate-stage/high-gradehepatocellularcarcinomaanditspossiblelinktoapoptosis.Materialandmethods:Thirty-fivecaseseachofchronicHCVhepatitistype4(groupI)andcirrhosiswithhepatocellularcarcinoma(HCC)complicatingchronicHCVhepatitis(groupsIIandIII)wereimmunohistochemicallyevaluatedusingap21raspolyclonalantibody.Theapoptoticindexwasdeterminedinhistologicsectionsusingtheterminaldeoxynucleotidyltransferase-mediatedd-UTPbiotinnickendlabeling(TUNEL)assay.Results:Significantdifferences(P=0.001)weredetectedinp21rasproteinexpressionbetweenthethreegroups.Anear2-foldincreaseinp21rasstainingwasobservedinthecirrhoticcasescomparedtothehepatitiscases,andp21rasexpressionwasdecreasedintheHCCgroup.p21rasexpressioncorrelatedwithstage(r=0.64,P=0.001)andgrade(r=-0.65,P=0.001)intheHCCgroupandgradeintheHCVgroup(r=0.44,P=0.008).Bothp21rasexpressionandTUNEL-LIweresignificantlylowerinlargeHCCscomparedtosmallHCCs(P=0.01each).TheTUNELvalueswerenegativelycorrelatedwithstageintheHCCgroup(r=-0.85,P=0.001).TheTUNELvalueswerealsonegativelycorrelatedwithgradeinboththeHCVandHCCgroups(r=0.89,P=0.001andr=-0.53,P=0.001,respectively).Thep21rasscoresweresignificantlycorrelatedwiththeTUNEL-LIvaluesintheHCCgroup(r=0.63,P=0.001)andHCVgroup(r=0.88,P=0.001).Conclusions:p21rasactsasaninitiatorinHCCcomplicatingtype4chronicHCVandisdownregulatedwithHCCprogression,whichmostlikelypromotestumorcellsurvivalbecauseitfacilitatesthedownregulationofapoptosiswithtumorprogression.
