Insulin-like Growth Factor-I cDNA Gene Transfer in vitro and in vivo

Our hypothesis is that gene transfer of an IGF-I CMV-cDNA with cholesterol containing cationic liposomes is an efficient tool Afor transient transfection of growth factors in vitro and in vivo. In vitro, we transiently cotransfected IGF-I cDNA with a CMV construct and a Lac Z CHK?CHK-galactosidase cDNA/CMV construct using cholesterol containing cationic liposomes and measured CHK?CHK-galactosidase and IGF-I mRNA and protein. In vivo, we subcutaneously injected 3-month-old male Sprague–Dawley rats with IGF-I cDNA and CHK?CHK-galactosidase cDNA into rat skin. After IGF-I and CHK?CHK-galactosidase were cotransfected into PC12 cells, Northern blot analysis showed that the peak time of IGF-I expression was 2 days for mRNA and 5 days for protein. In vivo, a cDNA/liposome ratio of 1:2 was most effective. IGF-I protein expression in IGF-I-transfected skin resulted in significant transfection from day 5 to day 7. In situ determination of CHK?CHK-galactosidase activity confirmed that transfections resulted in a restricted expression area.