Enhanced effects of TRAIL-endostatin-based double-gene-radiotherapy on suppressing growth, promoting apoptosis and inducing cell cycle arrest in vascular endothelial cells.

This study examined the effects of TRAIL-endostatin-based gene-radiotherapy on cellular growth, apoptosis and cell cycle progression in human vascular endothelial cells ECV304 in vitro. The expression of TRAIL and endostatin protein in ECV304 cells was detected by ELISA after the transfection of recombinant plasmid pshuttle-Egr1-shTRAIL-shES and X-ray irradiation. Then MTT assay was used for determining the cellular proliferation, and flow cytometry (FCM) plus Annexin V and propidium iodide (PI) double-staining or PI single-staining were employed for the detection of apoptosis and cell cycle progression. The results showed that expression of TRAIL and endostatin protein exhibited a time- and dose-dependent change in ECV304 cells after pshuttle-Egr1-shTRAIL-shES transfection in conjunction with irradiation. In the TRAIL-endostatin-based single- or double-gene-radiotherapy, the cell viability declined in a time- and dose-dependent manner, the percentage of cells at G(2)/M phase and apoptotic rate was increased, and the percentage of cells at G(0)/G(1) phase was lowered as compared with those receiving radiotherapy alone. Moreover, TRAIL-endostatin-based double-gene-radiotherapy demonstrated better effects on growth inhibition, promotion of apoptosis and induction of cell cycle arrest in ECV304 cells than single-gene-radiotherapy.