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 groups:group 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.
ABSTRACT
Objective To investigate the curative effect of the adenovirus-mediated fusion gene system driven by KDR promoter (AdKDR-CDglyTK) on a model of pancreatic cancer. Methods By using transplantation of the cultivated cells, human pancreatic cell line Capan-2 was injected subcutaneously on the back of nude mice to establish the animal model of the pancreatic cancer. Twenty nude mice were divided randomly and equally into four groups. The mice in group Ⅰ were injected with AdKDR-CDglyTK and 5-FC/GCV, those in group Ⅱ were injected with 5-FC/GCV, those in group Ⅲwere injected with AdKDR-CDglyTK and those in group Ⅳ received no any injection. AdKDR-CDglyTK was injected directly into the tumor and 5-FC/GCV was given by intraperitoneal injection. The observing parameters included common status, tumor bulk, tumor weight, inhibition rate of tumor growth, pathology, immunohistochemistry and treatment effect in each group. Electron microscopy was performed to observe the pathological changes of cells. The apoptotic cells in tumor were detected using the TUNEL assay. The expression of CDglyTK in tumors from each group was examined by RT-PCR. Results Tumor growth was dramatically inhibited in group Ⅰ. Tumor growth has no significant difference among groupⅡ , group Ⅲ and group Ⅳ. The apoptotic rate (34.20±4.60)% was significantly increased in group Ⅰ (F= 243. 22, P= 0. 00) and it had no significant difference among groupⅡ , group Ⅲ and group Ⅳ (P＞0.05). Conclusion AdKDR-CDglyTK with 5-FC/GCV can obviously inhibit the growth of human KDR-expressing pancreatic cell line Capan-2 and induce the cell apoptosis in vivo. The probable molecular mechanism lies in the facts that the system can cause a decline in the level of Bcl-2.
ABSTRACT
Objective To study the inhibitory effects of adenovirus-mediated fusion gene system driven by KDR promoter(AdKDR-CDglyTK) on angiogenesis and growth of pancreatic cancer.Methods The nude mice model was reproduced bearing pancreatic cancer cell lines Capan-2.Twenty nude mice were randomly and equally divided into four groups: AdKDR-CDglyTK and 5-FC/GCV were injected to the animals of group Ⅰ;group Ⅱ received 5-FC/GCV injection,group Ⅲ received AdKDR-CDglyTK injection,and group Ⅳ as control,received neither AdKDR-CDglyTK nor 5-FC/GCV.AdKDR-CDglyTK was injected directly into the tumor,while 5-FC/GCV was given by intraperitoneal injection.The treatment efficiency in each group was observed and the tumor microvessel density(MVD) was analyzed.RT-PCR was employed to examine the expression of CDglyTK in tumors.Results Tumor growth was dramatically inhibited in group Ⅰ,while no significant difference was found in group Ⅱ,group Ⅲ and group Ⅳ.The MVD in the four groups were 2.08?0.79,10.01?0.77,9.91?0.63 and 10.39?1.35,respectively(F=93.29,P=0.00).The MVD decreased significantly in group Ⅰ compared to the other three groups(P0.05).RT-PCR showed that a 2.4kB fragment had been amplified in the tumor tissues of groupⅠand group Ⅲ,but not in groupⅡand group Ⅳ.Conclusion AdKDR-CDglyTK with 5-FC and GCV can significantly inhibit the angiogenesis and growth of implanted pancreatic cancer in nude mice.