Objective To study the effects on MCF-7 breast cancer cells with combination of tamoxifen（TAM） and antisense oligonucleotide （ASODN） targeting survivin mRNA. Methods MCF-7 breast cancer cells were treated with a 20 mer ASODN targeting survivin mRNA and TAM, which were divided into three groups: TAM group (treated by TAM only), ASODN group (by ASODN only), and TAM+ASODN combined group (by TAM+ASODN combination). The growth inhibition of MCF-7 cells, the changes of cell cycles and apoptotic rate, the positive rate of survivin mRNA expression, and the activity of caspase-3 were tested by MTT, flow cytometry, hybridization in situ, and spectrophotometric method, respectively.Results The rate of growth inhibition of MCF-7 cells in the TAM+ASODN combined group was (62.26±3.92)%, which was significantly higher than that in the TAM group 〔(42.30±6.63)%〕 or ASODN group 〔(54.77±9.99)%〕, Plt;0.05. The apoptotic rate of MCF-7 cells was (28.08±4.32)% in the TAM+ASODN combined group, which was significantly higher than that in the TAM group 〔(18.94±4.01)%〕 or ASODN group 〔(21.12±3.95)%〕, Plt;0.01. The effect of arresting MCF-7 cells in G0/G1 phase in the TAM+ASODN combined group was ber than that in the TAM or ASODN group (Plt;0.05, Plt;0.01). The positive rate of survivin mRNA in the TAM+ASODN combined group was (13.38±3.45)%, which was significantly lower than that in the TAM group 〔(39.67±7.42)%〕 or ASODN group 〔(27.50±5.80)%〕, Plt;0.01. The activity of caspase-3 in the TAM+ASODN combined group （0.93±0.13） was significantly higher than that in the TAM group (0.50±0.09) or ASODN group (0.64±0.08), Plt;0.01. Conclusion The ASODN targeting survivin mRNA can promote the apoptosis of MCF-7 breast cancer cells, and make MCF-7 cells more sensitive to tamoxifen.
Objective To observe the effects of vascular endothelial growth factor antisense oligonucleotide (VEGF-ASODN) on expression of vascular endothelial growth factor (VEGF) and growth in gastric cancer cells. Methods The VEGF-ASODN was synthesized artificially with phosphorothioic acid. After transfecting with VEGF-ASODN in gastric cancer cells SGC-7901, the initial copy number of mRNA was detected by real-time RT-PCR, and the quantity of VEGF protein in both cell and supernatant were detected by ELISA. The levels of expression of survivin protein in cells were measured by Western blot. FCM and MTT method were used to detect cellular apoptosis and the activity of cells, respectively. The effect of transfection on the growth of cells was evaluated by growth curve. Results The copy number of VEGR mRNA, protein levels of VEGF in the cells and in culture fluid all decreased when the concentration of transfected VEGF-ASODN increased, as well as the levels of survivin protein （P＜0.05）. The ratio of apoptosis increased, the activity of cells also decreased as the concentration of transfected VEGF-ASODN increased （P＜0.05）. Conclusion Transfection with VEGF-ASODN in gastric cancer cells SGC-7901 can inhibit the expressions of VEGF and survivin remarkably. It can enhance cellular apoptosis and suppress growth of cells.