Multidrug resistance-associated protein-1 (MRP-1)-dependent glutathione disulfide (GSSG) efflux as a critical survival factor for oxidant-enriched tumorigenic endothelial cells.
Multidrug resistance-associated protein-1 (MRP-1)-dependent glutathione disulfide (GSSG) efflux as a critical survival factor for oxidant-enriched tumorigenic endothelial cells.
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多药耐药相关蛋白 1 (MRP-1) 依赖性谷胱甘肽二硫化物 (GSSG) 外流是富含氧化剂的致瘤内皮细胞的关键生存因子。
DOI：
10.1074/jbc.a115.688879
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Sen,ChandanK
中科院分区：
文献类型：
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作者：
Gordillo,GayleM;Biswas,Ayan;Khanna,Savita;Spieldenner,JamesM;Pan,Xueliang;Sen,ChandanK
内皮细胞肿瘤是婴儿最常见的软组织肿瘤。肿瘤形成内皮（EOMA）细胞能够逃脱细胞死亡的命运，尽管过度的核氧化剂负荷。我们以前的工作认识到核周氮氧化物-4作为一个关键的贡献者EOMA的增长。这项工作的目的是表征EOMA细胞逃避氧化剂毒性和茁壮成长的机制。在EOMA细胞中，与胞浆中相比，核GSSG/GSH比高5倍。与在健康小鼠主动脉内皮（MAE）细胞中观察到的比率相比，EOMA细胞中的GSSG/GSH是其两倍多。多药耐药相关蛋白-1（MRP-1）是一种主动的GSSG外排机制，在EOMA中的活性是MAE细胞的2倍。过度活跃的YB-1和Ape/Ref-1与MRP-1在EOMA中的高表达有关。邻近配体测定证明MRP-1和YB-1结合。这种结合使得MRP-1能够以一种对链霉素-B敏感的方式在EOMA中进行核靶向。MRP-1抑制以及敲低捕获的核GSSG，导致EOMA的细胞死亡。通过抑制GSSG还原酶（双氯亚硝基脲）或硫氧还蛋白还原酶（金诺芬）使细胞负载二硫化物也能有效引起EOMA死亡。总之，EOMA细胞通过GSSG的快速流出而在重氧化剂负荷下存活，如果被困在细胞内，GSSG是致命的。用于GSSG流出的超活性MRP-1系统作为这些细胞的关键存活因子，使其成为EOMA治疗的潜在靶点。
Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics.