Abstract: Abstract Objective: To observe the therapeutic efficacy of siRNA silencing P75 neurotrophin receptor (P75NTR) to induce apoptosis of U251 glioma cells. Methods The siRNA fragments targeting P75NTR were transferred into glioma cell line U251. RT-PCR was used to explore the expression of P75NTR mRNA. Platelet counting method was employed to get cell growth curve, in situ apoptosis assay to detect cell apoptosis, and Western blot to proteins expression of P75NTR, pro-apoptotic gene caspase-3 and anti-apoptosis gene Bcl-2, after gene transfection 1,3,5 and 7d. Results The siRNA targeting P75NTR can decrease mRNA expression of P75NTR in U251 cell, decrease cell proliferation, and increase cell apoptosis. P75NTR and Bcl-2 protein level in RNAi group were lower than the other two groups. This trend was contrast with the caspase-3. Conclusion The gene silencing technique by siRNA targeting P75NTR can induce cell apoptosis through the mechanisms regulating the expression of apoptosis-related genes. It is expected to become a new choice for gene therapy of glioma.

Key words: glioma, RNA interfere, invasion, apoptosis