2-脱氧-D-葡萄糖联合羟基喜树碱协同诱导乳腺癌细胞凋亡的作用

  目的  探究2-脱氧-D-葡萄糖(2-deoxy-D-glucose, 2-DG)联合羟基喜树碱(hydroxycamptothecin, HCPT)对乳腺癌细胞抗肿瘤活性的影响及其机制。  方法  采用2-DG(0、1.25、2.5、5、10、20 mmol/L)、HCPT(0、5、10、20、40 μmol/L)单独作用以及5 mmol/L 2-DG与各浓度HCPT联合作用于乳腺癌细胞MDA-MB-231与MCF-7，使用MTT法检测细胞增殖；溴化丙啶(propidium iodide，PI)检测5 mmol/L 2-DG、10 μmol/L HCPT单独作用以及联合作用对MDA-MB-231细胞的凋亡作用；不同浓度2-DG作用于MDA-MB-231细胞6 h后，测定细胞内ATP含量变化；Western blot检测MDA-MB-231细胞Akt、P-Akt、Bcl-2/Bax、PARP、Caspase-8和Caspase-3蛋白的表达。  结果  5 mmol/L 2-DG与HCPT联合具有协同作用，处理48 h结合指数(CI < 1)，合用组凋亡率均高于单用组(P < 0.05), 同时两者合用抑制Akt蛋白的磷酸化以及增加了Caspase-3蛋白的活化，增加了对PARP蛋白的剪切。  结论  2-DG联合HCPT可以协同诱导乳腺癌细胞凋亡，其机制可能是抑制肿瘤细胞能量生成以及抑制Akt蛋白的磷酸化和增强Caspase-3蛋白的活性。

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

  Objective  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.