Abstract:
Objective To observe the effect of the proteininhibitor of activated STAT 3 (PIAS3) on the proliferation and apoptosis of U251 glioma cells after PIAS3 expression was inhibited by RNAi.
Methods Three RNAi expression vectorstargeting PIAS3 were constructed and transfected into CHG-5 cells by liposomein vitro. The most efficient RNAi vector was subsequently selected by examiningthe mRNA expressions of PIAS3 in the transfected cells by semi-quantitativeRT-PCR. The selected RNAi vector was then transfected into U251 cells. After 48h of transfection, the mRNA and protein expressions of PIAS3 in glioma cellswere examined by semi-quantitative RT-PCR and western blot. Apoptosis wasobserved by flow cytometry using a double-staining method with FITC-conjugatedannexin V and PI. Flow cytometry was also applied in cell cycle assay.
Results RNAidownregulated the mRNA (P < 0.01) and protein (P < 0.01) expressionsof PIAS3 in transfected cells.RNAi promoted the resistance of U251 cells to apoptosisand subsequently altered the cell cycle. A high percentage of G2 phaseand a low percentage of Sphase were observed in U251 cells.
Conclusion The downregulation of PIAS3arrested U251 cells in the G2 phase andinduced the resistance of U251 cells to apoptosis.