摘要目的 探讨PTEN缺失是否影响小鼠成纤维细胞Cu/Zn超氧化物歧化酶(SOD)的表达水平及其意义.方法 采用Western blot验证及检测对照永生化小鼠胚胎成纤维细胞系PTEN+/+及PTEN缺失细胞系PTEN-/-内PTEN、磷酸化Akt、Cu/Zn SOD表达水平;Northern btot检测细胞内Cu/Zn SOD表达水平;单细胞碱性电泳检测细胞DNA损伤程度;荧光探针标记检测细胞内超氧阴离子水平;MTT法检测H2O2对细胞增殖状况的影响.结果 PTEN缺失细胞系PqEN-/-中,Cu/Zn SOD表达下调,Akt激酶磷酸化水平上调,细胞内超氧阴离子水平明显增高,空白组及H2O2处理后DNA损伤程度均较PTEN+/+细胞重,H2O2对其细胞增殖的抑制作用减弱.结论 PTEN缺失细胞内Cu/Zn SOD表达下调,并由此引起了细胞内活性氧持续高水平和氧化损伤累积以及活性氧对细胞增殖的抑制作用减弱.

abstractsObjective To investigate whether the deletion of PTEN affects the expression of Cu/ZnSOD and the related biology. Methods Protein and mRNA expression levels of PTEN, P-Akt, Cu/Zn SODin the control immortalized wild type mouse embryonic fibroblast cells (PTEN+/+) and PTEN-null cells(PTEN-/-) were evaluated by Western blot and Northern blot respectively. The level of superoxide anionswere detected using fluorescent probes. The DNA damage was documented by single cell alkalescence gelassay. MTT was used to study the effect of H2O2 on the proliferation of cells. Results The expression ofCu/Zn SOD was down regulated at both protein and mRNA levels, and the level of superoxide anionsincreased in the PTEN-null cells (PTEN -/-). The phosphorylation level of Akt kinase was up-regulated andthe antiproliferative effect of H2O2 decreased in PTEN-/- cells. Furthermore, DNA damage was observedsignificantly severer in both the blank control and H2O2 treated groups than that in the PTEN+/+ cells.Conclusions Deletion of PTEN affects the expression of Cu/Zn SOD. As a result, reactive oxygen species(ROS) keep at a high level, along with decrease of accumulated oxidative damage and the antiproliferativeeffect of ROS.