Ectopic expression of active processed form of atrial natriuretic peptide in skeletal myoblasts

Intraperitoneal gene delivery mediated by a novel cationic liposome in a peritoneal disseminated ovarian cancer model

We have previously synthesized a new cationic liposome that displays high efficiency and low toxicity, 3 beta[l-ornithinamide-carbamoyl] cholesterol (O-Chol), using solid-phase synthesis. In this study, O-Chol was applied to in vitro and in vivo models of ovarian cancer. Intraperitoneal gene delivery for peritoneal disseminated ovarian cancer in nude mice was achieved using a stable chloramphenicol acetyl transferase (CAT)-expressing ovarian cancer cell line (OV-CA-2774/CAT), which allowed us to quantify the exact tumor burden of organs. When luciferase and beta-galactosidase genes were used as reporter genes, O-Chol showed better efficiency than other commercial transfection reagents such as lipofectin, lipofectAMINE, DC-Chol, and FuGENE 6, both in vitro and in vivo. Moreover, the transfection efficiency of this new cationic lipid reagent remained high in serum-containing medium and under serum-free conditions. Furthermore, in vivo transfection with O-Chol showed high levels of gene expression specific to peritoneal tumor cells. Consequently, the O-Chol:DNA lipoplex appears to offer potential advantages over other commercial transfection reagents because of (1) its higher level of gene expression in vitro and in vivo; (2) its reduced susceptibility to serum inhibition; and (3) its highly selective transfection into tumor cells. These results suggest that the O-Chol:DNA lipoplex is a promising tool in gene therapy for patients with peritoneal disseminated ovarian cancer.

Efficient expression of the vascular endothelial growth factor gene in vitro and in vivo, using an adeno-associated virus vector

Vascular endothelial growth factor (VEGF) has proven to be one of the most effective growth factors for therapeutic angiogenesis. The biological efficacy of the adeno-associated virus (AAV) vector has recently been demonstrated in muscle tissues, including the heart. Apart from these promising insights into VEGF and the AAV vector, studies on VEGF gene transfer using the AAV vector have been limited. Here, we evaluate AAV-mediated VEGF gene transfer, both in vitro and in vivo, using the AAV-mVEGF vector that contains cDNA for murine VEGF(120) within an HCMV-driven expression cassette. Transient transfection of AAV-mVEGF plasmid significantly increased mVEGF expression in 293T cells. The secreted VEGF in the conditioned medium had strong biological activity, as confirmed by the Miles' vascular permeability assay. Transduction of 293T and HeLa cells with AAV-mVEGF stock of high titer, that is essentially adenovirus-free, showed significantly increased mVEGF expression above that of AAV-eGFP-transduced cells. When human umbilical vein endothelial cells were transduced, a higher level of mVEGF expression, together with higher cell counts, was observed compared to AAV-eGFP-transduced cells. In vivo transduction of mouse tibialis anterior muscle resulted in an increased level of mVEGF expression, and higher capillary-to-myofibre ratio, 8 weeks post-transduction. In a rat hindlimb ischemia model, regional blood flow, as well as the capillary-to-myofibre ratio, was significantly increased at 4 weeks post-transduction. These findings demonstrate the efficient delivery of the VEGF gene using an AAV vector, which has implications for angiogenic gene therapy in ischemic diseases.