热休克蛋白70对突变型p53稳定性的影响

目的：探讨热休克蛋白70(heat shock protein 70,HSP70)对突变型p53(mutant type p53,mtp53）稳定性的影响。方法：将反义HSP70真核表达重组质粒pXAHSP70脂质体介导转染至MCF7/Adr人乳腺癌细胞，PCR确定转染细胞中外源DNA存在，Western blot检测HSP70蛋白的抑制程度，p53稳定性实验分析反义HSP70 RNA对mtp53半衰期的改变。结果：转染重组质粒的MCF7/Adr细胞中HSP70蛋白表达下降42%，其胞内mtp53含量下降，半衰期缩短了6h，稳定性下降。结论：反义HSP70 RNA能够明显地降低mtp53稳定性，提示肿瘤细胞中HSP70高表达可增强mtp53的稳定性。

Effect of HSP70 on Stability of Mutant p53 Protein

Objective:The current study was designed to investigate the effect of heat shock pro tein 70(HSP70)on stability of mutant p53protein.Methods :Retroviral recombinant expressing antisense HSP70RNA was constructed and transfected into MCF7/Adr breast ca ncer cells.The existence of foreign DNA was identified by PCR method and t he HSP70protein level was determined by Western blot analysis.The half-life of m utant p53protein(mtp53)was measured by p53stability assay.Results:The stable expressing strain(MAp70)from transfected cells was obtained through G418selection.The foreign DNA in transfectant cells were confirmed by PCR,and the repre ssion rate of HSP70protein was 42%.T he half-life of mutant p53in MAp70cell was 12hours,significantly lower th an that of the control cells.Conclusion:Antisense HSP70RNA can decrease the HSP70protein level and significant ly increase instability of mutant p53protein in MCF7/Adr breast cancer cell.