Objective: To investigate cell proliferation and apoptosis status of human retinoblastoma cell line SO-Rb50 after knockdown of Survivin gene by means of small interfering RNA (siRNA).
Methods: Survivin specific siRNA designed from the human gene sequence and nonsense siRNA (as a negative control) was transfected into SO-Rb50 cells. The inhibition of the expression of Survivin mRNA and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Proliferation inhibition rate of SO-Rb50 cells was analyzed by MTT assay. Apoptotic rate and cell cycle were analyzed by flow cytometry (FCM) and the apoptotic morphology was observed by fluorescent microscope.
Results: The expression of Survivin at both mRNA and protein level in specific siRNA group decreased significantly in comparison with untransfected group and nonsense siRNA group after 24 hours of transfection. The proliferation of SO-Rb50 was inhibited in the Survivin specific siRNA group at the concentrations of 35, 70 and 100 nmol/L (P < 0.05). Flow cytometry showed obvious apoptotic peak in Survivin specific group with an accumulation of cells in the G0/G1 phase and a decrease in G2/M phase and S phase. Typical apoptosis morphology was also observed under fluorescent microscope.
Conclusions: Survivin specific siRNA could inhibit SO-Rb50 cell proliferation and induced apoptosis by knockdown of Survivin gene. Our data suggests that the use of Survivin-specific siRNA deserves further investigation as a novel approach to retinoblastoma therapy.