Effects of PIAS3 silencing by RNAi on the proliferation and apoptosis of U251 glioma cells in vitro / 中国肿瘤临床

ABSTRACT

Objective:To observe the effect of the proteininhibitor of activated STAT 3 (PIAS3) on the proliferation and apopto-sis 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-con-jugatedannexin 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 al-tered the cell cycle. A high percentage of G2 phaseand a low percentage of Sphase were observed in U251 cells. Conclusion:The down-regulation of PIAS3arrested U251 cells in the G2 phase andinduced the resistance of U251 cells to apoptosis.