Abstract
We investigated the transfection efficiency mediated by asialoganglioside-containing cationic liposomes. Previously we reported that monosialoganglioside GM1 (GM1a) enhanced transfection efficiency. In this study, we investigated the effects of sialic acid in gangliosides on transfection efficiency. Two mammalian culture cell lines HeLa and HepG2 were transfected with luciferase plasmids (pGL3) using cationic liposomes which contain monosialoganglioside GM1 (GM1a) or its asialic counterpart, asialoganglioside GM1 (GA1). Both GM1a and GA1 enhanced the efficiency of transfection mediated by cationic liposomes, and GA1 exhibited higher efficiency than GM1a in both cell lines. Transfection efficiency of ganglioside-containing liposomes was also assessed by the effects of antisense oligonucleotides (AS-ODN) for bcl-2 gene, which suppresses apoptotic cell death. Western blotting analysis revealed that the expression of Bcl-2 was decreased by AS-ODN, and the reduction of protein expression in cells treated with GA1-containing liposomes was more remarkable than that with GM1a-containing liposomes. Furthermore, the induction rate of apoptosis was higher in cells treated with AS-ODN with GA1-containing liposomes. Together with the results obtained by luciferase assay mentioned above, the removal of sialic acid from ganglioside causes the enhancement of efficiency of transfection mediated by cationic liposomes.
