Objective: To preliminarily investigate the mechanism of small interfering RNA (siRNA) induced apoptosis in glioma U251 cells by silencing basic fibroblast growth factor (bFGF).
Methods: U251 cells were divided into the normal control group, the mock group and experiment group, the mock and experiment group were transfected with mock vector (Ad-null) and the recombinant adenovirus carrying bFGF-siRNA (Ad-bFGF-siRNA) respectively at a multiplicity of infection (MOI) of 100. After 72 hours, the expression of related proteins was revealed by the method of Western blot. Mitochondrial transmembrane potential (ΔΨm) was measured with flow cytometry and confocal microscopy, Groups were compared using single factor analysis of variance (One-way ANOVA).
Results: After U251 cells were transfected with bFGF-siRNA, the results of Western blot showed that after 72 hours of transfection the bFGF protein in the experiment group decreased obviously, meanwhile Cytochrome C, Caspase-3 and Bax showed increased expression while in the Bcl-xl and Bcl-2 proteins decreased expression. The proportion of high mitochondrial membrane potential of cells by flow cytometry, the experimental group was 74.4% ± 4.7% decreased significantly compared with the control group 92.1% ± 2.5%, the mock group 90.9% ± 1.8% (F = 28.805, P < 0.05); laser scanning confocal microscopy results showed that the red fluorescence and green fluorescence ratio of the experimental group was 0.83 ± 0.12 decreased significantly compared with 1.36 ± 0.40 of the control group and 1.32 ± 0.35 of the mock group(F = 7.920, P < 0.05).
Conclusion: siRNA targeting bFGF induced U251 cell apoptosis may be achieved through the mitochondrial pathway.