OBJECTIVETo observe the effect of survivin antisense oligonucleotides (ASODN) on survivin and Smac gene expression in ovarian cancer SKOV3 cells and explore the role of survivin and Smac genes in ASODN-induced ovarian cancer cell cycle alteration and apoptosis and its molecular mechanisms.

METHODSSurvivin ASODN was introduced via Lipofectamine(TM)2000 into SKOV3 cells, whose growth activity was detected subsequently with MTT assay. The apoptosis index, cell cycle and changes in survivn and Smac protein expression were determined using flow cytometry. The changes in survivn and Smac mRNA expression were detected by RT-PCR.

RESULTSIn comparison with the control cells, cells transfected with difference concentrations of survivin ASODN exhibited significantly inhibited growth, and 48 h after the transfection, the IC(50) was about 600 nmol/L. After a 48-hour transfection of the cells with 600 nmol/L ASODN, the apoptosis index significantly decreased (t=6.3671, P<0.05), and the cell percentage in (1)/G(0) phase increased (t=10.3832, P<0.01), resulting also in significantly down-regulated survivin mRNA and protein expressions (t=3.5031, P<0.05; t=7.8146, P<0.01) and up-regulated Smac mRNA and protein expressions (t= 2.8011, P<0.05; t= 11.3917, P<0.01).

CONCLUSIONASODN against survivin can induce apoptosis of ovarian cancer cell line SKOV3 and results cell growth arrest in G(1)/G(0) phase by up-regulating Smac and down-regulating survivin expression. Survivin and Smac are closely correlated in their action on SKOV3 cell cycle and apoptosis, which is one of the important mechanisms of ovarian cancer development.