Growth inhibition of neurofibroma by ultrasound-mediated interferon γ transfection

We have previously shown that ultrasound-mediated transfection (sonotransfection) can be optimized using a concept based on the ultrasound-induced apoptosis produced in our in vitro experiments. At optimized conditions, we have shown, using five cancer cell lines, that sonotransfection is superior to other conventional nonviral methods. Interferon gamma (IFN-γ) transfection using lipofection has been found to markedly inhibit the proliferation of neurofibroma cell lines. In this study, we investigated whether sonotransfection of IFN-γ to neurofibroma cell lines can suppress cell proliferation.

The ultrasound device used was the SonoPore KTAC-4000, which is capable of various acoustic settings. Ultrasound transducers at an oscillation frequency of 1.011 MHz were used; the potential ideal conditions were an intensity of 0.17 W/cm(2) at a burst frequency of 0.5 Hz, 25% duty factor, and 30-s sonication duration. Cells were assayed at 3 and 5 days after sonication.

The transfection efficiency was found to be 12%. The ultrasound-treated cells were successfully transfected with IFN-γ genes as detected by enzyme-linked immunosorbent assay, and the cell growth ratio in the IFN-γ sonotransfection group tended to be lower than that in the other experimental groups.

These results suggested that IFN-γ sonotransfection could potentially become a nonsurgical method for treating skin lesions such as neurofibromas.