Synergistic Effect of 2-deoxy-D-glucose Combined with Hydroxycamptothecin on Apoptosis of Breast Cancer Cells

Abstract

To investigate the effect of 2-deoxy-d-glucose (2-DG) combined with hydroxycamptothecin (HCPT) on anti-tumor activity of breast cancer cells and its mechanism.  Methods  MDA-MB-231 and MCF-7 breast cancer cells were incubated with varying concentrations of 2-DG (0, 1.25, 2.5, 5, 10, 20 mmol/L), HCPT(0, 5, 10, 20, 40 μmol/L) and 2-DG (5 mmol/L) combined with HCPT. Cell viability was measured using the MTT assay; Propidium iodide (PI) detected the apoptosis of MDA-MB-231 cells by 5 mmol/L 2-DG, 10 μmol/L HCPT alone or in combination; MDA-MB-231 cells were treated with 2-DG (0, 2.5, 5, 10, 20 mmol/L) and the level of ATP was detected by ATP kit; the expression of Akt, p-Akt, Bcl-2/Bax, PARP, Caspase-8 and Caspase-3 proteins in MDA-MB-231 cells were measured by Western blot assay.  Results  The combination of 2-DG (5 mmol/L) and HCPT had a synergistic effect. The 48 h combination index (CI < 1) was higher than that of the single-use group (P < 0.05). At the same time, the combination of the two drugs inhibits the phosphorylation of Akt protein and increases the activation of Caspase-3 protein, thereby increasing the cleavage of PARP proteins.  Conclusion  The combination of 2-DG and HCPT can synergistically induce the apoptosis of breast cancer cells, which may be caused by inhibiting the energy generation of tumor cells, inhibiting the phosphorylation of Akt protein and enhancing the activity of caspase-3 protein.

Keywords: Breast cancer, 2-deoxy-D-glucose, Hydroxycamptothecin, Apoptosis