Objective    To construct a recombinant expression plasmid containing hTERT promoter and Fcy∷Fur suicide gene and to explore its killing effect on ovarian cancer cells.     Methods    ①In order to construct recombinant plasmid p2XEB-Fcy::Fur and pGL3-Pro-Fcy::Fur

Fcy::Fur gene was amplified first from plasmid pORF5-Fcy::Fur using PCR and inserted into plasmid p2XEB and pGL3-promoter respectively. ②We detected the expression of hTERT at mRNA level in SKOV3 and MRC-5 cells by RT-PCR and analyzed its promoter activity using luciferase analysis method. ③We transfected the 2 recombinant plasmids into SKOV3 and MRC-5 cells by ultrasound destructing microbubble and co-cultured cells with 5-FC. The changes of cell proliferation and apoptosis were analyzed by CCK-8 and AO/EB dyeing. Fcy::Fur mRNA was measured by RT-PCR.     Results    The plasmids of p2XEB-Fcy::Fur and pGL3-Pro-Fcy::Fur were constructed successfully and identified by restriction endonuclease and sequencing. SKOV3 and MRC-5 cells showed respectively positive and negative expression of hTERT mRNA

with hTERT promoter activity of 26.2% in SKOV3 cells and 0.65% in MRC-5 cells. Cell proliferation inhibitory rate was higher in p2XEB-Fcy::Fur/SKOV3 than that in p2XEB-Fcy::Fur/MRC-5 (P=0.036)

while the inhibitory rate was of no distinction in pGL3-Pro-Fcy::Fur/SKOV3 and pGL3-Pro-Fcy::Fur/MRC-5 (P=0.87). Except in p2XEB-Fcy::Fur/MRC-5

large scale of cell apoptosis and Fcy::Fur mRNA expression were found in the other three transfected groups (P0.01).     Conclusion    The recombinant plasmid of p2XEB-Fcy::Fur is constructed successfully

and in the combination with 5-FC

it can kill targeted ovarian cancer cells.