Targeting therapy for colorectal cancer with double suicide genes driven by VEGF promoter / 中华普通外科杂志

ABSTRACT

Objective To investigate the curative effect of an adenovirus-mediated fusion gene system driven by VEGF promoter (AdVEGF-CDglyTK) on a nude mouse model of colorectal cancer and analyze the mechanism underlying its therapeutic effect.Methods The animal model of the colorectal cancer was established by using transplantation of the cultivated cells,human colorectal cell line LoVo,via subcutaneous injection on the back of nude mice.Twenty nude mice were equally divided into four groupsgroup Ⅰ received injection of AdVEGF-CDgiyTK plus 5-flurocytosine/ganciclovir(5-FC/GCV);group Ⅱwere given 5-FC/GCV;group Ⅲ were with AdVEGF-CDglyTK;group Ⅳ were used as control.Results CDglyTK was expressed exclusively in the tumor tissues from the group Ⅰ and Ⅲ by RT-PCR.The phenotype and pathological analysis showed that tumor growth was dramatically inhibited in group Ⅰwhen compared with other three groups,while no significant difference was found between group Ⅱ,group Ⅲ and group Ⅳ.The TUNEL assay demonstrated that the apoptosis rate of 38.65% ± 4.20 significantly increased in group Ⅰ when compared with other three groups (F = 397.530,P =0.000).The tumor microvessel density of 3.08±0.79 decreased significantly in group Ⅰ (F = 34.081,P = 0.000) when compared with other three groups.Conclusion The results suggested that AdVEGF-CDglyTK with 5-FC/GCV can inhibit the tumor growth of colorectal cancer significantly in vivo by a mechanism of systeminduced apoptosis and the efficient suppression of angiogenesis.