Effects of silencing PTTG expression by small interference RNA.

OBJECTIVE We investigated the effects of small interference RNA (siRNA) on the cell proliferation inhibition, sensitivity to radiotherapy effects and cell apoptosis. The siRNA used here was specific to the pituitary tumor transforming gene (PTTG). MATERIALS AND METHODS Vectors containing the specific functional siRNAs for PTTG were designed and constructed. Cells were divided into four groups: (I) blank control group; (II) radiotherapy group: cells were exposed to X-ray radiation; (III) Group PTTG siRNA: transfected with PTTG siRNA; (IV) PTTG siRNA+ radiotherapy group: transfected with PTTG siRNA and then were exposed to X-ray radiation. HEC-1A cells were transfected by the specific interfering plasmids using Lipofectamine 2000 transfection reagent. The PTTG protein expression levels were analyzed using Western blot Cell proliferation was examined by MTT assay and the HEC-1A cell line apoptosis was evaluated by flow cytometry. RESULTS Recombinant small interference RNA (siRNA) expression vectors targeting PTTG were successfully constructed. The results of MTT showed that the growth of the HEC-1A cell was negatively influenced after cells were transfected with PTTG siRNA. Furthermore, PTTG siRNA combined with radiotherapy demonstrated more powerful inhibitory effects. Cell apoptosis rates were significantly increased in the radiotherapy group and the PTTG siRNA transfection group when compared to the control group. A more pronounced cell apoptosis rate was observed in the group that was treated with PTTG siRNA combined with radiotherapy. CONCLUSIONS Recombinant small interference RNA (siRNA) expression vector targeting PTTG successfully inhibited the cell proliferation and induced apoptosis in endometrial carcinoma cells and increased the cancer cells vulnerability to the effects of radiation.