OBJECTIVETo investigate the in vitro effect of HSV-tk/GCV using a hTERT promoter-driven vector system on Skov3 ovarian cancer cells.

METHODSAn expression vector (pBTdel-279-tk) containing tk gene under the hTERT promoter was constructed by molecular biological methods, and then was transfected into Skov3 ovarian cancer cells, normal ovarian epithelial cells (NOEC) and human embryonic lung fibroblast by cationic liposome. Following the transfection with tk, GCV was added, and MTT and flow cytometry methods were applied to investigate its antitumor effect. RT-PCR was used to detect the tk gene in ovarian cancer cells and normal cells after the transfection of pcDNA3-tk or pBTdel-279-tk.

RESULTSpBTdel-279-tk/GCV system induced apoptosis in hTERT-positive ovarian cancer cells, but not in hTERT-negative normal ovarian epithelial cells and fibroblasts. The hTERT promoter system was almost as efficient in inducing cancer cell death as the CMV promoter. tk gene was expressed in Skov3 cells and NOEC after pcDNA3-tk transfection, while positive was only in ovarian cancer cells after pBTdel-279-tk transfection.

CONCLUSIONThe telomerasespecific transfer of the tk gene under the hTERT promoter is a novel targeting approach for the treatment of ovarian cancer and may lead to an effective and specific gene therapy.