[Pilot study of PTEN deletion affecting the expression of Cu/Zn SOD].

Objective: To investigate whether the deletion of PTEN affects the expression of Cu/Zn SOD and the related biology.

Methods: Protein and mRNA expression levels of PTEN, P-Akt, Cu/Zn SOD in 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 anions were detected using fluorescent probes. The DNA damage was documented by single cell alkalescence gel assay. MTT was used to study the effect of H2O2 on the proliferation of cells.

Results: The expression of Cu/Zn SOD was down regulated at both protein and mRNA levels, and the level of superoxide anions increased in the PTEN-null cells (PTEN-/-). The phosphorylation level of Akt kinase was up-regulated and the antiproliferative effect of H2O2 decreased in PTEN-/- cells. Furthermore, DNA damage was observed significantly 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 antiproliferative effect of ROS.