OBJECTIVETo construct a tumor-targeting recombinant adenovirus vector containing hepatocellular carcinoma suppressor gene HCCS1 to enhance the safety of tumor treatment.

METHODSCCK-8 assay was used to observe different inhibitory effects on normal and malignant liver cells with high expressions of HCCS1 protein. The relative transcriptional activity of PEG-3p was quantified by luciferase assay. Recombinant adenovirus Ad-PEG-3p-HCCS1 was packaged with AdEasy system and confirmed by PCR. The tumor-targeted expression of HCCS1 protein in cells infected with Ad-PEG-3p-HCCS1 was determined by Western blot. Crystal violet assay and MTT assay were applied to observe the selective anti-tumor effects of the newly constructed virus in vitro.

RESULTSA higher inhibitory rate of about 60% was found in BEL-7404 and SW-620 than that in L02 and NHLF 96 h after the high expression of HCCS1. Luciferase assay showed 3.9-, 4.7-, and 1.5-fold transcriptional activity in BEL-7404, BEL-7405 and QGY-7703 respectively, in comparison with that in L02. Ad-PEG-3p-HCCS1 was constructed successfully and was verified by PCR. Western blot indicated that high expression of HCCS1 could be induced in BEL-7404 and QGY-7703 but not in L02. Crystal violet assay and MTT assay showed that it remarkably reduced the toxicity to L02 but still had enough antitumoral effect on Ad-CMV-HCCS1.

CONCLUSIONSWith high expression of HCCS1 the tumor cells we used are being inhibited more. PEG-3p has the tumor-selective driving function in malignant liver cells. Our recombinant adenovirus Ad-PEG-3p-HCCS1 can tumor-targeting induce HCCS1 expression in tumor cells, which can improve the safety of gene therapy with HCCS1.