In vitro and in vivo transfection of plasmid DNA in the Dunning prostate tumor R3327-AT1 is enhanced by focused ultrasound

Abstract

Gene therapy as a form of molecular medicine is expected to have a major impact on medical treatments in the future. However, the clinical use of gene therapy today is hampered by inadequate gene delivering systems to ensure sufficient, accurate and safe DNA uptake in the target cells in vivo. Nonviral transfection methods might have the advantage of safe application, but it would be helpful to increase their transfection rates, especially in vivo. In this study, we show that focused ultrasound provides an enhanced transfer of DNA plasmids in vitro and in vivo. In vitro, the ␤-galactosidase and luciferase DNA reporter plasmid were transfected into four cell lines (NIH 3T3 fibroblasts, malignant melanoma Mewo, HeLa, Dunning prostate tumor R3327-AT1). Ultrasound induced a 55-(Mewo) to 220-fold (AT1) stimulation resulting in transfection efficiencies in vitro

Development of safe and efficient novel nonviral gene transfer using ultrasound: enhancement of transfection efficiency of naked plasmid DNA in skeletal muscle

“…Recently, the transfection efficiency of plasmid DNA was increased by ultrasound in cultured cells. [34][35][36] Consistent with previous reports, [34][35][36] the present study revealed a marked increase in transfection efficiency using ultrasound. Nevertheless, the degree of increased efficiency was still not enough.…”

Ultrasonic drug delivery – a general review

“…Huber et al delivered a naked plasmid DNA reporter gene into subcutaneous Dunning prostate tumors in rats [76,77]. Insonation at 0.85 MHz produced a 10-fold to 15-fold increase in reporter activity compared to non-insonated controls.…”

Focused ultrasound (HIFU) induces localized enhancement of reporter gene expression in rabbit carotid artery

“…Although the ELISA test demonstrated increased gene expression after ultrasound, in the b-galactosidase staining, we could not detect b-gal-positive cells, presumably because of the low sensitivity of the X-gal staining procedure or a low protein expression per cell, which has been documented in earlier ultrasound studies. 23 Therefore, we were not able to assess transmural distribution of transgene expression. This discrepancy is a potential weakness of the study.…”

“…Ultrasonically induced heat elevation has not been reported to be an important mechanism of transfection induction, 23 while acoustic cavitation as a nonthermal phenomenon is considered to augment ultrasoundmediated transfection. 26,[29][30][31][32] Cavitation involves the formation of gaseous bubbles, a few micrometers in diameter, because of a disruption of the propagation medium by the negative pressure cycle in ultrasonic fields.…”

“…22 A wide range of ultrasonic waves have been used to augment gene transfer such as low-level diagnostic ultrasound, 20 ultrasonic shockwaves 22 and HIFU. 23 Furthermore, the application of ultrasound towards cardiovascular gene therapy was suggested in recent reports that demonstrated enhanced reporter gene expression following unfocused low-dose ultrasoundassisted transfection of vascular smooth muscle cells and cardiac myocytes 24,25 in the vessel system in vivo. 26 In the present study, we hypothesized that the use of focused sinusoidal ultrasound at higher intensities (HIFU) during intralumenal DNA administration could enhance the expression of reporter plasmid DNA in rabbit carotid artery in vivo.…”