Exogenous PTEN gene induces apoptosis in breast cancer cells

Abstract

To investigate the effects of exogenous PTEN gene on apoptosis of breast cancer cells. Human breast cancer cells of the line MDA468 were cultured. Recombinant plasmid pcDNA3.1-PTEN was constructed and transfected into the breast cancer cells with the lipofectAMINE 2000 transfection technique. Parental MDA468 cells and parental MDA468 cells transfected with blank vector pcDNA3.1(-) were used as control groups. RT-PCR was used to detect the expression of the PTEN mRNA and Western blotting was used to determine the expression of PTEN protein. Epithelial growth factor (EGF) was added into the cultures of MDA468 cells transfected with pcDNA3.1-PTEN or blank vector. Then Western blotting was used to detect the expression of phosphospecific protein kinase B (PKB/Akt) and focal adhesion kinase (FAK) protein stimulated by EGF. The aapoptosis of the MDA468 cells was determined by flow cytometry with the double-staining method using FITC-conjugated annexin V and PI. Expressions of PTEN mRNA and protein were shown in the MDA468 cells transfected with pcDNA3.1-PTEN by RT-PCR and Western blotting. Both the expression of p-AKT and that of p-FAK were down-regulated in the MDA468 cells transfected with pcDNA3.1-PTEN in comparison with those in the control cells. The apoptotic rate of the MDA468 cells transfected with PCDNA3.1-PTEN was 21.68%, significantly higher than those of the blank control cells (1.17%) and pcDNA3.1(-)-transfected cells (3.55%, both P < 0.01). Exogenous PTEN suppress the growth of human breast cancer cell and induces apoptosis by phosphatase activity, which provides a new clue to gene therapy for breast cancer.