[Adenovirus-mediated CDglyTK fusion gene system driven by KDR promoter selectively kills colorectal cancer cells].
OBJECTIVE
To observe the selective killing effect of adenovirus (Ad)-mediated double suicide gene driven by kinase domain-containing receptor(KDR) promoter on human colorectal cancer LoVo cells and human umbilical vein endothelial ECV304 cells.


METHODS
The plasmid pAdEasy-KDR-CDglyTK was transfected into 293 packaging cells for amplification of the infectious Ad and used to infect the KDR-producing cells (ECV304 and LoVo) and the KDR-nonproducing cells (LS174T) respectively. The three cells were treated with the prodrugs 5-flurocytosine (5-FC) and ganciclovir (GCV) at different concentrations after infection. The killing effects of the fusion gene system on the cells were evaluated. The distribution of cell cycle was detected by flow cytometry.


RESULTS
The infection rates of the recombinant Ad were similar among the 3 cells, gradually increasing with the increment of multiplicity of infection (MOI) and reaching 100% with the MOI of 200. The LoVo cells and ECV304 cells infected with Ad-KDR-CDglyTK were highly sensitive to both of the prodrugs (P>0.1), whereas the infected LS174T cells failed to exhibit similar sensitivity (P<0.001). The killing effect of CD/TK fusion gene on the target cells was much stronger than that of either suicide gene (P<0.001). The cell cycle of LoVo cells was arrested at G1 phase.


CONCLUSIONS
The CD/TK fusion gene system driven by KDR promoter can selectively kill KDR-expressing human colorectal cancer LoVo cells and endothelial cells.
Lin
Rong-kai
RK
Department of General Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. lrk7618401@163.com
Huang
Zong-hai
ZH
Su
Guo-qiang
GQ
Ke
Zhi-yong
ZY
Chen
Jian-xiong
JX
Zhou
Jin-jie
JJ
D000256:Adenoviridae / Q000235:genetics; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000628:therapy; D043525:Cytosine Deaminase / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology; 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 / Q000096:biosynthesis / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D011995:Recombination, Genetic; D013937:Thymidine Kinase / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured; D014471:Umbilical Veins / Q000166:cytology
D011993:Recombinant Fusion Proteins; D013937:Thymidine Kinase; D020794:Receptor Protein-Tyrosine Kinases; D043525:Cytosine Deaminase