Q.Yangetal.
Fig.3.Thechangeoflet-7aexpressionandinhibitionofanchorage-dependentgrowthbyoverexpressionoflet-7a.(AandB)Thechangeoflet-7aexpressionafter1,2,3,4,7,10,14and21daysfromlet-7amimicandlet-7amimicNCtransfectedoruntransfectedAGS(A)orBGC-823(B)cells.(CandD)Inhibitionofanchorage-dependentgrowthbythelet-7amimicinAGS(C)andBGC-823(D)cells.(E)Representativeresultsofcolonyformationofuntransfected,NC-transfectedandmimic-transfectedAGSandBGC-823cells.Thedatain(A–D)areshownasmean±SDfromthreeindependentexperiments.?P,0.05;??P,0.01,comparedwiththelet-7amimicNC-transfectedgroup.Pvalueswereobtainedbyone-wayanalysisofvarianceorthenon-parametricKruskal–WallisHtestformultiplecomparisons.
clinicopathologicfactorsorprognosisincancerpatients(22,23,30).Inthepresentstudy,the75%let-7aexpressionofgastriccarcinomasampleswassigni?cantlylowerthanthatofmatchednormaltissues,suggestingthatreducedlet-7aexpressionisafrequenteventingastriccancer.Furthermore,wefoundthattheexpressionleveloflet-7awasassociatedwiththedifferentiationstageinpatientsandthesameresultswereobservedinthecells.Ouranalyticalresultsshowedthattumortissueofpatientsandcelllineswithlowerlevelsoflet-7atendedtohavepoordifferentiation.Thisobservationwasconsistentwithanearlierreportthatidenti?edthelossoflet-7expressionasamarkerforlessdifferentiatedcancer(31).Theseresultsindicatedthatlet-7aexpressionmightbeanimportantin-dicatorforgastriccancerdiagnosisandclinicalstage.
miRNAshavebeenshowntobeimportantinthedevelopmentandmaintenanceofnormalcellularfunction,andalterationinexpressionofmiRNAscanresultinhumancancerinitiationandtumorprogres-sion.Somestudieshavereportedthatlet-7miRNAwasamasterregulatorofcellproliferationandcellcyclepathwaysinlung,co-lorectalandhepaticcells(22,23,32).However,noinformationisavailableontheimpa