OBJECTIVETo evaluate the toxic effects of the CD-TK fusion gene systems against prostate carcinoma cell line RM-1 for assessing the value of suicidal gene therapy for prostate carcinoma.

METHODSCD-TK fusion gene and green fluorescent protein (GFP) gene were transfected into RM-1 cells through adenovirus vectors. RT-PCR was used to demonstrate successful transfection and transcription of the suicidal genes. The toxic effects of 5-FC and GCV used alone or in combination on the transfected cells were observed by MTT assay, with the non-transfected RM-1 cells serving as control.

RESULTSCytotoxic activity of CD/5-FC and TK/GCV systems against RM-1 cells was observed, and combined treatment with the two drugs resulted in significantly lowered survival of CD-TK-expressing cells (P<0.05). After exposure to 5-FC and GCV for 72 h, the survival rate of the transfected cells decreased to 71.56% and 47.27%, respectively, and their combined use resulted in a survival rate as low as 18.46%.

CONCLUSIONCD-TK fusion double suicidal gene system can produce significantly stronger toxic effect against RM-1 cells in vitro than either of suicidal genes.