Bcl-2 small interfering RNA inhibits the growth of human lymphoma transplanted subcutaneously in nude mice

Abstract

OBJECTIVE To investigate whether small hairpin RNA (shRNA) targeting Bcl-2 mRNA could inhibit the growth of lymphoma transplanted subcutaneously in nude mice. METHODS Recombinant Bcl-2 shRNA expression vector with green fluorescence protein (GFP) gene was constructed and preserved in our lab. We evaluated the antitumor effect of the Bcl-2 shRNA in vivo which was the model of nude mice bearing Raji cells xenografts. Human Raji cells were injected subcutaneously into nude mice to establish lymphoma models. When the diameters of tumor were above 0.5 cm after Raji cells injection,the mice bearing tumor were randomly divided into four groups: saline control group, negative shRNA group, plasmid vector group, Bcl-2 shRNA group. The polyethylenimine (PEI) was used to transfect shRNA into tumor. The mixed PEI and shRNA was injected into tumors. The growth and size of tumor were observed. Tissue was stained by H&E for its pathological morphology. The expression of Bcl-2 mRNA in the tumor mass was detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS A significant difference in median tumor weight was observed in mice treated with Bcl-2 shRNA, compared with those in the groups of negative shRNA or plasmid vector or saline solution ( P < 0.05). Pathological evaluation was completed in all excised tumors from nude mice bearing Raji cells xenografts. The tumor tissue of the mice treated with Bcl-2 shRNA showed apoptosis, serious necrosis of the cells and inflammatory cells infiltration. There was no change in the morphology of cells among negative shRNA , plasmid vector and saline solution group. In the group of the Bcl-2 shRNA, the expression levels of Bcl-2 mRNA of the tumor tissue were eff ectively inhibited ( P < 0.05). CONCLUSION The shRNA targeting at the Bcl-2 mRNA could inhibit the growth of human lymphoma transplanted subcutaneously in nude mice.