Inhibition of expression of bcl-2 gene by siRNA in glioma cell line U251

AIM: To evaluate the effectiveness of small interference RNA on inhibiting bcl-2 gene expression. METHODS: With Ambion's software and kit, we designed and synthesized siRNA targeted bcl-2, which were transfected into astrocytoma cell line U251 with lipofectamine. The non-transfected cells and treatment with antisense drug G-3139 were taken as controls. MTT was used to detect the inhibitory rate of cell growth. Flow cytometric method was used to detect the change in cycle of the cells. The inhibitory effect of siRNA on mRNA level was detected by RT-PCR and on protein level was by immunohistochemical method. RESULTS: For the living rate of cell, siRNA 2, 3, 5, 6 groups were significantly lower than siRNA 1, 4 groups, lipofectamine and control group at 24, 48, and 96 h. siRNA 1-6 groups only had statistic difference with antisense group at 24, 48 h. As for PCR and immunohistochemical method, the expression of bcl-2 on siRNA 2, 3, 5, 6 groups were significant lower than other groups. The results of flow cytomytric method showed the cells transfected with siRNA 1-6 and antisense were blocked at S stage. CONCLUSION: siRNA inhibited bcl-2 gene expression more than 50%.