[Adenovirus-mediated CDglyTK fusion gene system driven by KDR promoter selectively kills MCF-7 breast cancer cells and vascular endothelial cells].
OBJECTIVE
To observe the selective killing of MCF-7 human breast cancer cells and vascular endothelial ECV304 cells by adenovirus (Ad)-mediated double suicide gene driven by KDR promoter.


METHODS
The plasmid pAdEasy-KDR- CDglyTK was transfected into 293 packaging cells for amplification of the infectious Ad, which were then used to infect KDR-producing ECV304 and MCF-7 cells and LS174T cells that did not produce KDR. The infected cells were treated with 5-FC and/or GCV at different doses to observe the cell-killing and bystander effects of AdKDR-CdglyTK. The cell cycle changes were also detected by flow cytometry.


RESULTS
The Ad at the titer of 2.0 x 10(12) pfu/ml was obtained after the amplification, whose infection rates of the cells were similar, but could be increased gradually with the multiplicity of infection (MOI) till reaching 100% with the MOI of 200. The infected cells exhibited different sensitivities to the two prodrugs: ECV304 cells and MCF-7 cells infected with Ad-KDR-CDglyTK showed similar high sensitivity to the prodrugs (P=1.00), whereas the infected LS174T cells appeared to be less sensitive (P<0.001). The killing effect of CD/TK fusion gene on the target cells was much stranger than that of either suicide gene (P<0.001), but all exhbiting considerable bystander effect. In addition, the cell cycle of MCF-7 cells was arrested at G1 phase.


CONCLUSIONS
CD/TK fusion gene system driven by KDR promoter can selectively kill KDR-expressing vascular endothelial cells and MCF-7 cells.
Su
Guo-qiang
GQ
Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. suguoquang66@yahoo.com.cn
Huang
Zong-hai
ZH
Liu
Zhi-feng
ZF
Guo
Ai-hua
AH
Yu
Jin-long
JL
Li
Zhou
Z
Song
Hui-juan
HJ
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000473:pathology* / Q000628:therapy; D043525:Cytosine Deaminase / Q000096:biosynthesis / Q000235:genetics*; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D041722:Genes, Transgenic, Suicide / Q000235:genetics; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D011401:Promoter Regions, Genetic / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D013937:Thymidine Kinase / Q000096:biosynthesis / Q000235:genetics*; D014407:Tumor Cells, Cultured
D011993:Recombinant Fusion Proteins; D013937:Thymidine Kinase; D020794:Receptor Protein-Tyrosine Kinases; D043525:Cytosine Deaminase