Publications (2)0 Total impact
Article: [Suppression of osteosarcoma in vitro by coexpression of antisense VEGF165 cDNA and thymidine kinase gene].[show abstract] [hide abstract]
ABSTRACT: To investigate the effect of VEGF expression in osteosarcoma cell line and the target killing effect of HSV1-TK/GCV system on transfected osteosarcoma cells under hypoxia conditions. Eukaryotic expression plasmid with HRE promoter was constructed to express the antisense VEGF165 cDNA and Hygromycin phospho-transferase-thymidine kinase (HyTK) fusion gene. The recombinant vectors were then transfected into osteosarcoma cell line MG63 with lipofectin mediated gene transfer methods. PCR and RT-PCR were used to confirm the presence and expression of TK gene. The sensitivity of transfected cells to GCV and "bystander effect (BSE)" of HSV1-TK/GCV system under normoxia or hypoxia conditions were measured by MTT assay and mixed co-culture experiment. The expression of VEGF protein was detected by ELISA under hypoxia condition. Cell cycle phase distribution was determined by flow cytometry. In addition, electromicroscopy was used to document ultrastructural alterations. The eukaryotic expression vector pBI-HRE-AsVEGF165 -HyTK was constructed successfully. The transfected cell line MG63TV was established and confirmed by PCR and RT-PCR of the presence of transgene and its mRNA expression. GCV was toxic to transfected cells in a concentration-dependent manner. The sensitivity to GCV toxicity was 100 times higher under hypoxia condition than that under normoxic condition. The mixed culture experiments showed that the "bystander effect" was enhanced significantly under hypoxia condition. VEGF expression of transgene cells under hypoxia condition decreased 50% compared to that of normal condition. Under hypoxia and GCV, DNA synthesis of MG63TV cells was inhibited along with an increase of cells at G0 approximately G1 phase, apoptosis and necrosis. Antisense VEGF expression driven by HRE promoter in combination with hypoxia can provide a target inhibition of VEGF expression in human osteosarcoma cells, with an enhanced selective killing effect and BSE of the HSV-TK/GCV system. The double-gene co-expression system in study provides experimental basis for therapy against osteosarcoma by a synchronous antiangiogenic and suicide gene approach.Zhonghua bing li xue za zhi Chinese journal of pathology 04/2007; 36(3):190-5.
Article: [Targeted inhibition of vascular endothelial growth factor (VEGF) expression in human osteosarcoma cell line by antisense VEGF165 cDNA promoted by hypoxia reaction element].[show abstract] [hide abstract]
ABSTRACT: Utilizing the hypoxia inducible factor 1/hypoxia reaction element (HIF-1/ HRE) gene regulation system to construct antisense vascular endothelial growth factor (VEGF165) cDNA eukaryotic expression vector promoted by HRE, and investigate its targeted inhibiting VEGF expression of osteosarcoma cells in hypoxia environment. Eukaryotic expression plasmid with HRE promoter was constructed containing luciferase reporter gene and antisense VEGF165 cDNA by using PCR and recombinant DNA techniques. The recombinant vectors were transfected into osteosarcoma cells with lipofectin method. Hypoxia-inducible reporter gene expression was determined by liquid scintillation analyzer and the expression of VEGF protein was detected by ELISA method. The eukaryotic expression plasmid containing antisense VEGF165 and luciferase promoted by HRE was constructed successfully. After being transferred into MG63 cells, luciferase expression was increased 3.5 x 10(2) times and VEGF protein expression decreased 45% under hypoxia condition. Antisense VEGF165 cDNA expression, efficiently realized by HRE promoter under hypoxia condition, provides an experimental basis for targeted antiangiogenesis of tumors.Zhonghua bing li xue za zhi Chinese journal of pathology 10/2005; 34(9):588-91.