FAK (
focal adhesion kinase), which plays a pivotal role in mediating cell proliferation, survival and migration, is frequently overexpressed in human
malignant glioma. The expression of FAK increases with the advance of tumour grade and stage. Based on these observations, we hypothesized that attenuation of FAK expression may have inhibitory effects on the growth of
malignant glioma. In the present study, human
glioma cell line U251 was transfected with plasmids containing U6 promoter-driven shRNAs (small-hairpin RNAs) against human FAK using cationic
liposome. The effects of FAK knockdown in U251 cells in vitro were analysed by using flow cytometry and PI (
propidium iodide)-staining assays. Based on the encouraging in vitro results with FAK silencing, plasmids encoding FAK-targeted
shRNA were encapsulated by
DOTAP (dioleoyltrimethylammonium
propane):Chol (
cholesterol) cationic
liposome and injected via tail vein to evaluate its therapeutic efficiency on suppressing tumour growth in a human
glioma xenograft model.
PCNA (
proliferating-cell nuclear antigen), CD34 immunostaining and TUNEL (
terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay were used to assess the changes in tumour angiogenesis, apoptosis and proliferation respectively. The results indicated that
DOTAP:Chol cationic
liposome could deliver therapeutic plasmids systemically to tumour xenografts, resulting in suppression of tumour growth. Treatment with plasmid encoding FAK-targeted
shRNA reduced mean tumour volume by approx. 70% compared with control groups (P<0.05), accompanied with angiogenesis inhibition (P<0.05), tumour cell proliferation suppression (P<0.05) and apoptosis induction (P<0.05). Taken together, our results demonstrated that
shRNA-mediated silencing of FAK might be a potential therapeutic approach against human
malignant glioma.