Knock-down of glutaminase 2 expression decreases glutathione, NADH, and sensitizes cervical cancer to ionizing radiation
Knock-down of glutaminase 2 expression decreases glutathione, NADH, and sensitizes cervical cancer to ionizing radiation
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谷氨酰胺酶 2 表达的敲低会降低谷胱甘肽、NADH，并使宫颈癌对电离辐射敏感
DOI：
10.1016/j.bbamcr.2013.08.003
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发表时间：
2013-12-01
影响因子：
5.1
通讯作者：
Liang, Houjie
中科院分区：
文献类型：
--
作者：
Xiang, Lisha;Xie, Ganfeng;Liang, Houjie
磷酸盐激活的线粒体谷氨酰胺酶（GLS 2）被认为与谷氨酰胺代谢升高有关。它在催化谷氨酰胺水解为谷氨酸中起重要作用。本研究旨在探讨GLS 2对宫颈癌放射抵抗的影响。应用免疫组织化学方法检测144例宫颈癌组织（58例放射抵抗，86例放射敏感）和15例癌旁正常宫颈组织中GLS 2的表达。HeLa细胞用累积剂量为50戈伊的X射线处理6个月，产生抗性亚系HelaR。Western blot检测GLS 2的表达。用集落存活法检测细胞的辐射抗性。流式细胞术检测细胞凋亡。采用定量分析试剂盒检测谷胱甘肽（GSH）、活性氧（ROS）、NAD（+）/NADH比值和NADP（+）/NADPH比值。使用异种移植物来证实GLS 2对体内辐射抗性的作用。GLS 2在放射抵抗患者肿瘤组织中的表达明显高于放射敏感患者。在体外，抗辐射细胞系HeLaR表现出显着增加的GLS 2水平比其亲本细胞系HeLa。GLS 2沉默的辐射抗性细胞HeLaR显示出显著增强的辐射敏感性，具有响应于辐射的较低的集落存活和较高的凋亡。在体内，具有GLS 2沉默的HeLaR的异种移植物对辐射更敏感。在分子水平上，GLS 2的敲低通过减少抗氧化剂GSH、NADH和NADPH的产生来增加照射后HeLaR细胞内ROS水平。GLS 2可能在宫颈癌患者的放射抵抗中起重要作用。(C)2013爱思唯尔有限公司版权所有。
Phosphate-activated mitochondrial glutaminase (GLS2) is suggested to be linked with elevated glutamine metabolism. It plays an important role in catalyzing the hydrolysis of glutamine to glutamate. The present study was to investigate the potent effect of GLS2 on radioresistance of cervical carcinoma. GLS2 was examined in 144 cases of human cervical cancer specimens (58 radioresistant specimens, 86 radiosensitive specimens) and 15 adjacent normal cervical specimens with immunohistochemistry. HeLa cells were treated with a cumulative dose of 50 Gy X-rays, over 6 months, yielding the resistant sub-line HelaR. The expressions of GLS2 were measured by Western blot. Radioresistance was tested by colony survival assay. Apoptosis was determined by flow cytometry. The levels of glutathione (GSH), reactive oxygen species (ROS), NAD(+)/NADH ratio and NADP(+)/NADPH ratio were detected by quantization assay kit. Xenografts were used to confirm the effect of GLS2 on radioresistance in vivo. The expressions of GLS2 were significantly enhanced in tumor tissues of radioresistant patients compared with that in radiosensitive patients. In vitro, the radioresistant cell line HeLaR exhibited significantly increased GLS2 levels than its parental cell line HeLa. GLS2 silenced radioresistant cell HeLaR shows substantially enhanced radiosensitivity with lower colony survival and higher apoptosis in response to radiation. In vivo, xenografts with GLS2 silenced HeLaR were more sensitive to radiation. At the molecular level, knockdown of GLS2 increased the intracellular ROS levels of HeLaR exposed to irradiation by decreasing the productions of antioxidant GSH, NADH and NADPH. GLS2 may have an important role in radioresistance in cervical cancer patients. (C) 2013 Elsevier B.V. All rights reserved.