BTG2 inhibits the proliferation, invasion, and apoptosis of MDA-MB-231 triple-negative breast cancer cells

The purposes of this study were to investigate the effects of B cell translocation gene 2 (BTG2) on the proliferation, apoptosis, and invasion of triple-negative breast cancer and to provide an experimental basis for the future treatment of human triple-negative breast cancer. A pcDNA3.1-BTG2 eukaryotic expression vector was constructed and transfected into the MDA-MB-231 human triple-negative breast cancer cell line using lipofection. Then, relevant changes in the biological characteristics of the BTG2-expressing cell line were analyzed using MTT (tetrazolium blue), flow cytometry, and Transwell invasion chamber assays. Additionally, the effects of BTG2 expression on cyclin D1, caspase 3, and matrix metalloproteinases 1/2 (MMP-1/-2) expression were analyzed. Cell proliferation was significantly lower in the pcDNA3.1-BTG2-transfected group compared to the empty vector and blank control groups (p < 0.05). There was no significant difference between the empty vector and blank control groups. FCM results demonstrated that there were significantly more cells in the G1 phase of the cell cycle and fewer S phase cells in the pcDNA3.1-BTG2 group than in the empty vector and blank control groups (p < 0.05). Additionally, the proportion of cells that migrated across the membrane was significantly lower in the pcDNA3.1-BTG2 group than in the empty vector and blank control groups (p < 0.05). Cyclin D1 and MMP-1/-2 expression were significantly lower in MDA-MB-231 cells transfected with pcDNA3.1-BTG2 as compared to the empty vector and blank control groups (p < 0.05). Caspase 3 expression was significantly higher in MDA-MB-231 cells from the pcDNA3.1-BTG2 group compared to the empty vector and blank control groups (p < 0.05). In conclusion, BTG2 may inhibit MDA-MB-231 proliferation and promote apoptosis. Additionally, BTG2 may also inhibit the invasion of MDA-MB-231 human triple-negative breast cancer cells.