Carnesecchi S, Rougemont A-L, Doroshow J H, Nagy M, Mouche S, Gumy-Pause F, Szanto I
Department of Cellular Physiology and Metabolism and; Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva 4, Switzerland.
Division of Clinical Pathology and.
Free Radic Biol Med. 2015 Jul;84:22-29. doi: 10.1016/j.freeradbiomed.2015.02.027. Epub 2015 Mar 19.
Reactive oxygen species (ROS) are key modulators of apoptosis and carcinogenesis. One of the important sources of ROS is NADPH oxidases (NOXs). The isoform NOX5 is highly expressed in lymphoid tissues, but it has not been detected in any common Hodgkin or non-Hodgkin lymphoma cell lines. In diverse, nonlymphoid malignant cells NOX5 exerts an antiapoptotic effect. Apoptosis suppression is the hallmark feature of a rare type of lymphoma, termed anaplastic lymphoma kinase-positive (ALK(+)) anaplastic large-cell lymphoma (ALCL), and a major factor in the therapy resistance and relapse of ALK(+) ALCL tumors. We applied RT-PCR and Western blot analysis to detect NOX5 expression in three ALK(+) ALCL cell lines (Karpas-299, SR-786, SUP-M2). We investigated the role of NOX5 in apoptosis by small-interfering RNA (siRNA)-mediated gene silencing and chemical inhibition of NOX5 using FACS analysis and examining caspase 3 cleavage in Karpas-299 cells. We used immunohistochemistry to detect NOX5 in ALK(+) ALCL pediatric tumors. NOX5 mRNA was uniquely detected in ALK(+) ALCL cells, whereas cell lines of other lymphoma classes were devoid of NOX5. Transfection of NOX5-specific siRNA and chemical inhibition of NOX5 abrogated calcium-induced superoxide production and increased caspase 3-mediated apoptosis in Karpas-299 cells. Immunohistochemistry revealed focal NOX5 reactivity in pediatric ALK(+) ALCL tumor cells. These results indicate that NOX5-derived ROS contribute to apoptosis blockage in ALK(+) ALCL cell lines and suggest NOX5 as a potential pharmaceutical target to enhance apoptosis and thus to suppress tumor progression and prevent relapse in pediatric ALK(+) ALCL patients that resist classical therapeutic approaches.
活性氧（ROS）是细胞凋亡和致癌作用的关键调节因子。ROS的重要来源之一是NADPH氧化酶（NOXs）。NOX5亚型在淋巴组织中高度表达，但在任何常见的霍奇金淋巴瘤或非霍奇金淋巴瘤细胞系中均未检测到。在多种非淋巴恶性细胞中，NOX5发挥抗凋亡作用。凋亡抑制是一种罕见类型淋巴瘤（称为间变性淋巴瘤激酶阳性（ALK(+)）间变性大细胞淋巴瘤（ALCL））的标志性特征，也是ALK(+) ALCL肿瘤治疗耐药和复发的主要因素。我们应用逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹分析来检测三种ALK(+) ALCL细胞系（Karpas-299、SR-786、SUP-M2）中NOX5的表达。我们通过小干扰RNA（siRNA）介导的基因沉默以及使用荧光激活细胞分选（FACS）分析和检测Karpas-299细胞中半胱天冬酶3的切割情况，研究了NOX5在细胞凋亡中的作用。我们使用免疫组织化学方法检测ALK(+) ALCL儿童肿瘤中的NOX5。在ALK(+) ALCL细胞中独特地检测到了NOX5信使核糖核酸（mRNA），而其他淋巴瘤类型的细胞系中没有NOX5。转染NOX5特异性siRNA和对NOX5进行化学抑制可消除钙诱导的超氧化物产生，并增加Karpas-299细胞中半胱天冬酶3介导的细胞凋亡。免疫组织化学显示儿童ALK(+) ALCL肿瘤细胞中有局灶性NOX5反应性。这些结果表明，源自NOX5的ROS有助于ALK(+) ALCL细胞系中的凋亡阻滞，并提示NOX5作为一种潜在的药物靶点，可增强细胞凋亡，从而抑制儿童ALK(+) ALCL患者的肿瘤进展并预防复发，这些患者对经典治疗方法耐药。
