Effect of Bcl-2-siRNA on proliferation and apoptosis of pediatric acute B lymphoblastic leukemia (A-BLL) cells.

This study analyzed the effect of small interfering RNA specific for the Bcl-2 gene (siRNA Bcl-2) on the proliferation and chemotherapeutic sensitivity of pediatric A-BLL cells. Marrow samples were obtained from sixty newly-diagnosed A-BLL pediatric patients. The Bcl-2 mRNA expression in these samples was quantified by real time polymerase chain reaction. The Bcl-2 mRNA re-expression was analyzed by RNA interference using Bcl-2-siRNA. Cellular proliferation was detected using the MTT (Thiazolyl Blue Tetrazolium Bromide) assay. The cell apoptosis was quantified by flow cytometry. The Bcl-2 mRNA expression was significantly higher in the drug-resistance group than in the chemotherapy sensitivity group prior to chemotherapy (P < 0.05). In addition, the Bcl-2 mRNA expression in the chemotherapy sensitivity group was significantly higher before chemotherapy than that after chemotherapy (P < 0.05). The Bcl-2 mRNA expression significantly decreased in the leukemic cells of the Bcl-2-siRNA transfection group. We observed statistically significant differences in the relative mRNA expression levels among the Bcl-2-siRNA transfection, blank control, liposome empty transfection, and unrelated sequence oligonucleotide groups (P < 0.05). The rate of apoptosis in pediatric A-BLL leukemic cells was observed to increase significantly after transfection with Bcl-2-siRNA compared to the control, liposome empty transfection, and unrelated sequence oligonucleotide groups (P < 0.05). Therefore, we concluded that Bcl-2-siRNA can successfully inhibit the multiplicative capacity of A-BLL leukemic cells and promote apoptosis.