Research On The Subcellular Localization Of P21Protein Expression And Its Influence On Human Bronchial Epithelial Cell Apoptosis

Objective:Study on the subcellular localization of P21protein overexpression and itsinfluence on cell apoptosis,when p21expression plasmid transfects human bronchialepithelial cell line (16HBE).Method:p21expression plasmid transfects16HBE cell,and then extract total RNA andnucleus and cytoplasm protein respectively,measure the subcellular localization ofp21protein overexpression by RT-PCR and western blot semi-quantitative methodand analyze the influence of cell apoptosis by flow cytometry and fluorescencemicroscope.Result:1. P21plasmid group is significantly differ from control group (p=0.000), andp21RNA expression has no obvious difference between the empty plasmid group andblank control group (p=0.704).2. P21protein in the cytoplasm of p21expression plasmid group is obviouslyhigher than that of the protein from nucleus (p=0.002), while p21protein fromnucleus of the empty plasmid group and the blank control group is higher than that inthe cytoplasm (p=0.033,0.033).P21protein in the cytoplasm of p21expressionplasmid group is higher than others (p=0.000).The empty plasmid group and blankcontrol group have no difference on the cytoplasm protein (p=0.87). P21protein inthe nucleus among the three groups have no significant difference (p>0.05).3. P21plasmid transfecting16HBE cells can lead to cell apoptosis, apoptosis islower than the empty plasmid group and the blank control group,16HBE cellapoptosis in time-dependent in time≤48hour.But in time72h cell apoptosis and deathobviously increase.Apoptosis rate in time24h of p21plasmid group is obviouslyhigher than that of48h (p=0.036);As for the empty plasmid group (p=0.033) andblank control group (p=0.037) apoptosis rate of24h is obviously lower than that of48h.P21plasmid and the empty plasmid group or blank control group have significant difference (p <0.05), while the empty plasmid group and the blank control grouphave no significant difference (p>0.05) on apoptosis rate.Conclusion:P21protein expresses mainly in the cytoplasm and that can suppress cellapoptosis,when P21expression plasmid transfects human bronchial epithelial cell line(16HBE).