Levels of effectiveness of gene therapies targeting survivin and its splice variants in human breast cancer cells

抄録

In order to develop an effective strategy of breast cancer therapy targeting survivin and its splice variants survivin-ΔEx3 and survivin-2B, the present study constructed four expression vectors by fusing the survivin antisense gene, the survivin (T34A) gene, the survivin-ΔEx3 antisense gene, and the survivin-2B gene with the enhanced green fluorescent protein (eGFP) gene. Each of these vectors was transiently transfected into the B-Cap-37 human breast cancer cell line. The effects of these four vectors with diverse genes on the proliferation and apoptosis of B-Cap-37 breast cancer cells were examined and compared in vitro using MTT and flow cytometry assays. Results of the MTT assay indicated that all four gene therapy plasmids were most effective at inhibiting the proliferation of B-Cap-37 cells 72 h after transfection. However, the four gene therapies had different rates of cell inhibition. pcDNA3.1(+)-egfp-anti-survivin and pcDNA3.1(+)-survivin (T34A)-egfp had almost equivalent or better effectiveness at suppressing cell growth. pcDNA3.1(+)-egfp-anti-survivin-ΔEx3 moderately inhibited the growth of B-Cap-37 cells. In contrast, pcDNA3.1(+)-survivin-2B-egfp had limited inhibition of cell growth. Similar profile of effectiveness of four gene therapies in soliciting cell apoptosis was also observed. These results suggest the relative importance of targeting survivin and its splice variant survivin-ΔEx3 in breast cancer treatment.