Heterogeneity in 2-deoxy-D-glucose-induced modifications in energetics and radiation responses of human tumor cell lines
Heterogeneity in 2-deoxy-D-glucose-induced modifications in energetics and radiation responses of human tumor cell lines
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DOI：
10.1016/s0360-3016(01)01534-6
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发表时间：
2001-07-15
影响因子：
7
通讯作者：
Jain, V
中科院分区：
文献类型：
--
作者：
Dwarkanath, BS;Zolzer, F;Jain, V
目的：葡萄糖类似物和糖酵解抑制剂2-脱氧-D-葡萄糖(2-DG)可通过抑制放射后修复过程而不同程度地增强肿瘤细胞的辐射损伤。本研究旨在探讨2-DG诱导的能量代谢改变与细胞放射反应的关系，并确定预测放射+2-DG联合治疗肿瘤反应的最相关参数(S)。方法与材料：以6种人肿瘤细胞系(胶质瘤：BMG-1和U-87，鳞癌：4451和4197，黑色素瘤：MeWo和BE-11)为研究对象。细胞暴露于2GyCo-60或250KVPX射线，并在保液条件下维持2~4h，以促进修复。照射时加入的2-DG(5 mM，与葡萄糖等摩尔)在液体保存过程中存在。葡萄糖利用率、乳酸产量(酶分析)和腺嘌呤核苷酸(高效液相和毛细管等速电泳法)作为能量代谢的参数进行了研究。结果：胶质瘤细胞系(BMG-1和U-87)的葡萄糖消耗和乳酸产生是鳞癌细胞系(4197和4451)的近2倍，三磷酸腺苷(ATP)含量在3.0~6.5毫微摩尔/细胞之间变化不大，而能量负荷(0.86~0.90)变化不大。在胶质瘤细胞系中，2-DG的存在抑制了葡萄糖的利用和糖酵解的速率，在鳞癌细胞系中抑制了15-20%，而在所有四种细胞系中，ATP水平都降低了近40%。与鳞癌4451和MeWo细胞相比，胶质瘤细胞中ATP：ADP比率的下降幅度更大(接近40%)；相反，2-DG的存在使鳞癌4451中的ADP/AMP比率降低了3倍，而在胶质瘤细胞系BMG-1中观察到了增加。2-DG显著降低了所有细胞的DNA修复初始速率，导致BMG-1、U-87和4451细胞在修复2小时后出现过度的残留损伤，而在其他细胞株中则没有明显的差异。在BMG-1细胞中，从潜在的致命损伤中恢复也受到显著抑制。2-DG可使黑色素瘤细胞系(MeWo)辐射诱导的微核形成率增加近60%，而对胶质瘤细胞系(BMG-1和U-87)的微核形成率有中等程度的增加(25%~40%)。结论：2-DG对不同肿瘤细胞系的能量学和辐射反应的影响存在较大差异，能量代谢与放射生物学参数之间的关系本质上是复杂的。2-DG诱导的辐射反应的改变与ATP水平的变化没有严格的相关性。然而，在高葡萄糖使用率和糖酵解的细胞中，观察到2-DG对辐射损伤的显著增强，这似乎是决定2-DG+放射治疗联合治疗的两个最重要的因素。(C)2001年爱思唯尔科学公司。
Purpose: The glucose analog and glycolytic inhibitor, 2-deoxy-D-glucose (2-DG), has been shown to differentially enhance the radiation damage in tumor cells by inhibiting the postirradiation repair processes. The present study was undertaken to examine the relationship between 2-DG-induced modification of energy metabolism and cellular radioresponses and to identify the most relevant parameter(s) for predicting the tumor response to the combined treatment of radiation + 2-DG.Methods and Materials: Six human tumor cell Lines (glioma: BMG-1 and U-87, squamous cell carcinoma: 4451 and 4197, and melanoma: MeWo and Be-11) were investigated. Cells were exposed to 2 Gy of Co-60 gamma -rays or 250 kVP X-rays and maintained under liquid-holding conditions 2-4 h to facilitate repair. 2-DG (5 mM, equimolar with glucose) that was added at the time of irradiation was present during the liquid holding. Glucose utilization, lactate production (enzymatic assays), and adenine nucleotides (high performance liquid chromatography and capillary isotachophoresis) were investigated as parameters of energy metabolism. Induction and repair of DNA damage (comet assay), cytogenetic damage (micronuclei formation), and cell death (macrocolony assay) were analyzed as parameters of radiation response.Results: The glucose consumption and lactate production of glioma cell lines (BMG-1 and U-87) were nearly 2-fold higher than the squamous carcinoma cell lines (4197 and 4451), The ATP content varied from 3.0 to 6.5 femto moles/cell among these lines, whereas the energy charge (0.86-0.90) did not show much variation. Presence of 2-DG inhibited the rate of glucose usage and glycolysis by 30-40% in glioma cell lines and by 15-20% in squamous carcinoma lines, while ATP levels reduced by nearly 40% in all the four cell lines. ATP:ADP ratios decreased to a greater extent (similar to 40%) in glioma cells than in squamous carcinoma 4451 and MeWo cells; in contrast, presence of 2-DG reduced ADP:AMP ratios by 3-fold in the squamous carcinoma 4451, whereas an increase was noted in the glioma cell line BMG-1. 2-DG significantly reduced the initial rates of DNA repair in all cells, resulting in an excess residual damage after 2 h of repair in BMG-1, U-87, and 4451 cell lines, whereas no significant differences could be observed in the other cell lines. Recovery from potentially lethal damage was also significantly inhibited in BMG-1 cells. 2-DG increased the radiation-induced micronuclei formation in the melanoma line (MeWo) by nearly 60%, while a moderate (25-40%) increase was observed in the glioma cell lines (BMG-1 and U-87). Presence of 2-DG during liquid holding (4 h) enhanced the radiation-induced cell death by nearly 40% in both the glioma cell lines, while significant effects were not observed in others.Conclusions: The modifications in energetics and radiation responses by 2-DG vary considerably among different human tumor cell Lines, and the relationships between energy metabolism and various radiobiologic parameters are complex in nature. The 2-DG-induced modification of radiation response does not strictly correlate with changes in the levels of ATP. However, a significant enhancement of the radiation damage by 2-DG was observed in cells with high rates of glucose usage and glycolysis, which appear to be the two most important factors determining the tumor response to the combined treatment of 2-DG + radiation therapy. (C) 2001 Elsevier Science Inc.