Cell AgingTumor Suppressor Protein p53Cyclin-Dependent Kinase Inhibitor p16TelomereFibroblastsAging, PrematureTelomere ShorteningCyclin-Dependent Kinase Inhibitor p21Telomerasebeta-GalactosidaseAgingDNA DamageCell ProliferationCells, CulturedRetinoblastoma ProteinCell Cycle CheckpointsCell CycleCell Line, TumorOxidative StressCell Transformation, NeoplasticTumor Suppressor Protein p14ARFSirtuin 1Signal TransductionTumor Suppressor ProteinsCell LineProgeriaLongevityTelomeric Repeat Binding Protein 2NeoplasmsNuclear ProteinsGenes, p16RNA, Small InterferingReactive Oxygen SpeciesDiploidy