OBJECTIVETo explore the effects of lentivirus-mediated RNA interference silencing HMGA2 on proliferation and expressions of cyclin B2 and cyclin A2 in HL-60 cell line.

METHODSThe protein and mRNA expressions of HMGA2 in HL-60 cells transduced by recombinant lentivirus producing HMGA2 gene short hairpin (shRNA) were examined by Western-blot and reverse transcription-polymerase chain reaction (RT-PCR) analysis; The effects of the lentivirus on cell proliferation inhibiting rate, the ability of cell proliferation and cell cycle were analyzed by soft agar colony formation assay and FCM, respectively; The protein and mRNA expressions of cyclin B2 and cyclin A2 were also examined by Western-blot and RT-PCR.

RESULTSRecombinant lentivirus producing HMGA2 shRNA was successfully constructed, which was identified by PCR and sequencing; Stable HMGA2-deficient HL-60 cell line was established by puromycin, its mRNA and protein expression inhibition rates were (80.66 ± 7.98)% and (76.35 ± 12.72)%, respectively. Silencing of endogenous HMGA2 resulted in efficient inhibition of the cellular proliferative activity, low and flat of the cell growth curve and the lack of typical character of exponential growth. FCM revealed significant more cell cycle G(2)/M arrest \[(30.00 ± 5.78)%\] in HL-60 cell line transfected specific shRNA than control group \[(13.90 ± 4.07)%\] (P < 0.05). The cyclin B2 mRNA and protein expression inhibition rates in stable HMGA2-deficient HL-60 cell line were (67.55 ± 7.69)% and (51.77 ± 4.81)%, respectively, while the expression of cyclin A2 had no significant change compared with control group.

CONCLUSIONRNAi silencing of HMGA2 down-regulated cyclinB2, significantly inhibited the proliferation of HL-60 cells and induced the accumulation of HL-60 cells in the G(2)/M phase. Thus, HMGA2 may be an important target for anti-leukemia therapy.