Effects of down-regulation of clusterin by small interference RNA on human acute myeloid leukemia cells.

AIMS AND BACKGROUND Up-regulation of clusterin is associated with the survival and progression of various malignancies, and down-regulation of clusterin promotes apoptosis and inhibits invasion. The aim of this study was to explore the effect of clusterin small interference RNA (siRNA) on the proliferation, apoptosis and invasion of HL-60 acute myeloid leukemia (AML) cells. METHODS siRNA transfection was performed using Lipofectamine™2000 reagent. Relative protein expressions were quantified by Western blot. Trypan blue assay was performed to assess tumor cell proliferation after siRNA transfection. The cytotoxic effect of clusterin siRNA on leukemic cells was measured using MTT assay. Apoptosis was detected using fluorescence microscopy assay. Migration and invasion was detected after clusterin was silenced. RESULTS Clusterin siRNA clearly lowered clusterin protein levels in a time- dependent manner, leading to marked inhibition of cell survival, proliferation and invasion. Furthermore, clusterin down-regulation significantly enhanced the extent of HL-60 apoptotic cells. CONCLUSIONS Our results suggest that the down-regulation of clusterin by siRNA can effectively trigger apoptosis and inhibit the proliferation and invasion of leukemic cells. Therefore, clusterin siRNA may be a potent adjuvant in AML therapy.