Inhibitory effects of small interfering RNA on the expression of cbl-b gene in mouse lymphocytes

Objective To design, synthesize screen small interfering RNA (siRNA) targeting to Casitas B-cell lineage lymphoma-b (cbl-b).Methods Four pairs of 21 nucleotide siRNAs directed to Cbl-b mRNA were designed and synthesized by utilizing RNA design software to simulate secondary structure of cbl-b mRNA in mice. These siRNAs were respectively transfected into lymphocytes in 96 shadows mask by oligofectamine package, and untreated and unspecific siRNA-transfected lymphocytes served as controls. The expression of cbl-b protein was detected by Western blotting.Results When the work concentration of siRNA was 100 nmol/L, transfection efficiency of lymphocytes was highest, up to (87.48±1.94)% and the mean fluorescence intensity was strongest, up to 33.09±1.77. Compared with bland controls, the expression of cbl-b protein level was markedly down-regulated in siRNA-transfected lymphocytes. The inhibitory rate of the siRNA of the target-4 was highest, up to 85%. The expression of cbl-b protein in unspecific siRNA-transfected lymphocytes had no significant changes.Conclusion siRNA-4, which can highly effectively inhibit protein expression of cbl-b gene, was screened successfully, and its inhibition effect can maintain near 48 h. It is hopeful that the cbl-b siRNA will activate lymphocytes directly by cbl-b gene silencing, and kill tumor by activate immunization. Key words: cbl-b;  Small interfering RNA;  Lymphocytes