Antisurvivin Oligonucleotides Promote In Vitro Cisplotin Induction of Apoptosis in Osteosarcoma Cells

OBJECTIVE To study the effect of antisense oligonucleotides (ASODN) of survivin, a member of a gene family of Inhibitors of apoptosis, on the ability of cisplatin (DDP) to induce apoptosis in osteosarcoma cells.

METHODS ASODN of survivin were synthesized and transfected into osteosarcoma OS-732 cells. The effects of ASODN alone, and with DDP as well as the effect of sense oligonucleotides (SODN) with and without DDP were examined. The reverse tanscriptase-polymerase chain reaction (RT-PCR) was utilized to detect the expression of survivin mRNA in each group of OS-732 cells. The cells were examined by flow cytometry (FCM) and staining with acridine orange (AO) to determine the morphology of the cells and the level of apoptosis in each group. The MTT assay was used to estimate the condition of cell growth.

RESULTS In comparing the cells transfected with ASODN with the control, SODN and DDP groups, we found that the expression of survivin mRNA was significantly decreased (P<0.01), and the level of apoptosis enhanced. ASODN-treated cells appeared atrophic with condensed chromatin, characteristic of typical apoptotic changes. Cell growth was relatively inhibited in the ASODN groups. Furthermore, the apoptotic index (Al) and cell growth-inhibition ratio (IR) were significantly higher in the ASODN+DDP group compared to each group treated with a single agent and compared to the SODN+DDP group.

CONCLUSION ASODN can specifically inhibit the expression of the survivin gene in OS-732 cells, and correspondingly suppress survivin function, resulting in an increase in sensitivity to DDP and thus the ability of DDP to induce apoptosis in osteosarcoma cells.