Inhibition of tumor cell glutamine uptake by isolated neutrophils.
Inhibition of tumor cell glutamine uptake by isolated neutrophils.
复制标题
分离的中性粒细胞抑制肿瘤细胞谷氨酰胺的摄取。
DOI：
10.1172/jci113680
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Thomas,EL
中科院分区：
文献类型：
--
作者：
Learn,DB;Thomas,EL
测定了肉豆蔻酸酯佛波酯（PMA）刺激的中性粒细胞对CCRF-CEM细胞的抗肿瘤活性。中性粒细胞和肿瘤细胞孵育(a)作为悬浮液连续混合，以最大限度地提高氧气的可用性，或(b)离心后作为颗粒，以最大限度地提高细胞与细胞的接触。然后将这些细胞与[14C]谷氨酰胺短暂孵育，在阻止肿瘤细胞进一步损伤的条件下孵育。当细胞作为悬浮液孵育时，受刺激的中性粒细胞的髓过氧化物酶/过氧化氢/氯化物系统介导了肿瘤细胞谷氨酰胺摄取的抑制。通过加入过氧化氢酶（一种髓过氧化物酶抑制剂）或清除次氯酸或氯胺的化合物，抑制作用被阻断。当细胞作为颗粒孵育时，部分抑制不能以这种方式被阻断，表明非氧化机制有助于抑制。在这两种系统中，谷氨酰胺摄取的抑制是快速的，并且在效应细胞/靶细胞比低至0.5:1时获得。这种抑制作用是在不导致[51Cr]-铬酸盐标记的细胞释放51Cr的条件下获得的，这表明抑制谷氨酰胺摄取测量的是细胞毒性而不是细胞溶解。只有当细胞以高E/T比作为颗粒一起孵育1小时或更长时间时，才观察到51Cr的释放。这种细胞溶解是由髓过氧化物酶系统介导的，没有观察到细胞溶解的非氧化贡献。结果表明，当以细胞毒性而非细胞溶解作为活性指标时，受刺激的中性粒细胞是有效的抗肿瘤效应细胞。由于谷氨酰胺是许多肿瘤细胞生长所必需的，抑制谷氨酰胺摄取可能具有显著的抑瘤或杀瘤作用。
Antitumor activity of phorbol myristate acetate-(PMA) stimulated neutrophils was measured against CCRF-CEM cells. Neutrophils and tumor cells were incubated (a) as a suspension with continuous mixing to maximize the availability of oxygen or (b) after centrifugation as a pellet to maximize cell-cell contact. The cells were then incubated briefly as a suspension with [14C]glutamine under conditions that blocked further damage to the tumor cells. When cells were incubated as a suspension, inhibition of tumor-cell glutamine uptake was mediated by the myeloperoxidase/hydrogen peroxide/chloride system of stimulated neutrophils. Inhibition was blocked by adding catalase, an inhibitor of myeloperoxidase, or compounds that scavenge hypochlorous acid or chloramines. When cells were incubated as a pellet, a portion of the inhibition could not be blocked in this way, indicating that a nonoxidative mechanism contributed to inhibition. In both systems, inhibition of glutamine uptake was rapid and was obtained at effector-cell/target-cell ratios as low as 0.5:1. This inhibition was obtained under conditions that did not result in 51Cr release from cells labeled with [51Cr]-chromate, indicating that inhibition of glutamine uptake measured cytotoxicity rather than cytolysis. 51Cr release was observed only when cells were incubated together for an hour or more as a pellet at high E/T ratios. This cytolysis was mediated by the myeloperoxidase system, and a nonoxidative contribution to cytolysis was not observed. The results indicate that stimulated neutrophils are potent antitumor effectors cells when cytotoxicity rather than cytolysis is the measure of activity. Because glutamine is required for growth of many tumor cells, inhibition of glutamine uptake may represent a significant tumoristatic or tumoricidal effect.