高浓度胰岛素抑制人白血病细胞株K562增殖的实验研究

目的 探讨高浓度胰岛素(insulin,INS)对K562细胞株增殖的抑制作用及其机理。方法 用不同浓度胰岛素处理K562细胞，分别用CCK-8法、细胞计数法和台盼蓝拒染法检测K562细胞的增殖活性，同时检测培养基中葡萄糖浓度变化；流式细胞术检测K562细胞的凋亡效应；并分别采用不同浓度的胰岛素样生长因子-1（IGF-1）和IGF-1受体非特异性阻滞剂苏拉明（Suramin）对高浓度胰岛素影响K562细胞增殖作用进行干预。结果 胰岛素在0.1～1 mU/mL浓度下具有明显促进K562细胞增殖的作用，而高浓度胰岛素（1.6～100 mU/mL）则相反；无论培养基中葡萄糖浓度高低，高浓度胰岛素都有对K562细胞增殖的抑制作用；高浓度胰岛素抑制K562细胞增殖呈时效和量效关系；0.1、1、10、100 mU/mL胰岛素处理K562细胞48 h，与对照组比较，0.1、1 mU/mL浓度下抑制细胞凋亡，而10、100 mU/mL浓度下促进细胞凋亡（P均<0.05）；IGF-1能逆转高浓度胰岛素对K562细胞增殖的抑制作用，并且具有量效和时效关系；Suramin能增强高浓度胰岛素对K562细胞增殖的抑制作用，并且具有量效和时效关系。结论 胰岛素对K562细胞有双重作用，即在0.1～1 U/mL浓度下促进细胞增殖、抑制凋亡，高浓度（1.6～100 mU/mL）下抑制细胞增殖、促进凋亡，且其抑制作用与培养基中葡萄糖代谢无关与抑制IGF-1途径有关。

Inhibitory Effect of High Concentration Insulin on the Proliferation of Human Leukemia Cell Strain K562

Objective To study the impact of high concentration insulin on the proliferation and apoptosis of K562 cell strain. Methods K562 cells were treated with different concentrations of insulin. The proliferation activity was tested by CCK-8 assay, cytometry, and trypan blue exclusion. The alterations in glucose concentration of the culture media were monitored while the apoptosis of K562 cells was detected by flow cytometry. The effects of high concentration insulin on the proliferation of K562 cells were inhibited by varying concentrations of insulin-like growth factor-1 (IGF-1) and Suramin. Results Under the range of concentration (0.1-1 mU/mL), insulin facilitated the proliferation of K562 cells. In contrast, insulin at high concentrations (1.6-100 mU/mL) had the opposite effect, in a dose- and time-dependent manner. Different concentrations of glucose in the culture medium had no significant influence on the inhibitory effect of high concentration insulin on the proliferation of human leukemia cell strain K562. At low concentration insulin inhibited the apoptosis of K562 cells, in a dose-dependent manner. In contrast, insulin at high concentration had the opposite effect, in a dose-dependent manner. Furthermore, IGF-1 reversed the inhibitory effect of high concentration insulin on the proliferation of K562 cell in a dose- and time-dependent manner. Suramin, which is an IGF-1 receptor non-specific blocker, had the opposite effect on K562 cells, also in a dose- and time-dependent manner. Conclusion These results indicate insulin has a dual effect on K562 cells. The dual effect is probably mediated by the binding of insulin and IGF-1R. Inhibitory effect of high concentration insulin on the proliferation of K562 cells is unrelated with the glucose metabolism in the culture media.