Antisense oligonucleodes targeting the focal adhesion kinase inhibit proliferation, induce apoptosis and cooperate with cytotoxic drugs in human glioma cells

To examine the role of focal adhesion kinase in human glioma cells, we studied its effects on proliferation and apoptosis using FAK antisense oligonucleotide. U251 MG cells were transfected with ODNs, sense FAK, mismatch FAK and antisense-FAK, respectively. Expression of FAK proteins were detected by Western blots and Immno-fluoressence. Cell apoptosis and mitochondrial membrane potential were analyzed by flow cytometry. Caspase-3 activity was measured by spectrofluorometer. MTT assay was used to examine changes in cell proliferation. The protein expression of FAK in U251 MG cells decreased in antisense-FAK ODNs group significantly. Caspase-3 activity increased in cells treated with antisense-FAK and down-regulated when treated with caspase-3 inhibitor. The level of cell apoptosis and loss of mitochondrial membrane potential in antisense-FAK group was higher than in the mismatch sense group. Cells proliferation was inhibited by antisense-FAK, and the effects were clearly additive when antisense oligonuceotides were added to cells treated with the anticancer agents. The results suggest that antisense-FAK ODNs inhibit U251 MG cells proliferation and induce their apoptosis. It is possible that FAK via mitochondrial and caspase-3 inhibits U251 MG cells apoptosis. And antisense oligonucleotide treatment enhances U251 MG cells sensitivity to chemotherapy.