Cationic
lipids and
polyamines have been used as non-viral gene transfer
reagents, both in vitro and in vivo. One of the limitations to their use in vivo is the inhibition of gene delivery by serum. We showed previously that, in the absence of serum, relatively high cytotoxicity in
oral cancer cell lines could be achieved via transfection of the Herpes Simplex Virus
thymidine kinase (HSV-tk) gene followed by treatment with
ganciclovir (GCV), despite the low efficiency of transfection (Konopka et al., Gene Ther. Mol. Biol. 8 (2004) 307-318). In this study we evaluated the effect of high concentrations (20-60%) of
fetal bovine serum (FBS) on the transfection efficiency of two novel
reagents, the polycationic
liposome,
Metafectene, and the
polyamine reagent,
GeneJammer, in HSC-3 and H357 human
oral squamous cell carcinoma (OSCC) cells. We also examined whether the HSV-tk gene delivered in the presence of FBS (up to 60%, could induce cell death following treatment with GCV. Transfection was optimized using a
luciferase-expressing plasmid. Both
Metafectene- and
GeneJammer-mediated
luciferase gene expression in HSC-3 cells was reduced by 40-50% when transfection was performed in the presence of 20-60% FBS. The delivery of the HSV-tk gene by
Metafectene in the absence and the presence of 60% FBS, followed by GCV treatment for 9 days, resulted in 95% and 70% cytotoxicity, respectively. With
GeneJammer, transfection in 0% and 60% FBS resulted in 90% and 40% cytotoxicity, respectively, after 9 days. In contrast, very low transfection activity and a much higher inhibitory effect of serum were observed in H357 cells. Nevertheless, about 35% GCV-mediated cytotoxicity was observed with H357 cells at both 0% and 60% FBS, using GeneJamer. Thus,
Metafectene and
GeneJammer can be used in the delivery of genes in
biological milieu and in the gene therapy of OSCC in animal models.