McLaughlin Martin, Pedersen Malin, Roulstone Victoria, Bergerhoff Katharina F, Smith Henry G, Whittock Harriet, Kyula Joan N, Dillon Magnus T, Pandha Hardev S, Vile Richard, Melcher Alan A, Harrington Kevin J
The Institute of Cancer Research, London, UK.
University of Surrey, Guildford, UK.
Mol Ther Oncolytics. 2020 Jan 17;16:238-249. doi: 10.1016/j.omto.2020.01.001. eCollection 2020 Mar 27.
Reovirus type 3 Dearing (reovirus) is a tumor-selective oncolytic virus currently under evaluation in clinical trials. Here, we report that the therapeutic efficacy of reovirus in head and neck squamous cell cancer can be enhanced by targeting the unfolded protein response (UPR) kinase, protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK). PERK inhibition by GSK2606414 increased reovirus efficacy in both 2D and 3D models , while perturbing the normal host cell response to reovirus-induced endoplasmic reticulum (ER) stress. UPR reporter constructs were used for live-cell 3D spheroid imaging. Profiling of eIF2a-ATF4, IRE1a-XBP1, and ATF6 pathway activity revealed a context-dependent increase in eIF2a-ATF4 signaling due to GSK2606414. GSK2606414 blocked eIF2a-ATF4 signaling because of the canonical ER stress agent thapsigargin. In the context of reovirus infection, GSK2606414 induced eIF2a-ATF4 signaling. Knockdown of eIF2a kinases PERK, GCN2, and PKR revealed eIF2a-ATF4 reporter activity was dependent on either PERK or GCN2. Knockdown of ATF4 abrogated the GSK2606414-induced increase in reovirus protein levels, confirming eIF2a-ATF signaling as key to the observed phenotype. Our work identifies a novel approach to enhance the efficacy and replication of reovirus in a therapeutic setting.
3型迪林呼肠孤病毒（呼肠孤病毒）是一种肿瘤选择性溶瘤病毒，目前正在临床试验中进行评估。在此，我们报告称，通过靶向未折叠蛋白反应（UPR）激酶、蛋白激酶R（PKR）样内质网激酶（PERK），可增强呼肠孤病毒在头颈部鳞状细胞癌中的治疗效果。GSK2606414对PERK的抑制作用在二维和三维模型中均提高了呼肠孤病毒的疗效，同时扰乱了宿主细胞对呼肠孤病毒诱导的内质网（ER）应激的正常反应。UPR报告基因构建体用于活细胞三维球体成像。对eIF2a-ATF4、IRE1a-XBP1和ATF6信号通路活性的分析显示，由于GSK2606414，eIF2a-ATF4信号传导呈背景依赖性增加。由于经典的内质网应激剂毒胡萝卜素，GSK2606414阻断了eIF2a-ATF4信号传导。在呼肠孤病毒感染的背景下，GSK2606414诱导了eIF2a-ATF4信号传导。敲低eIF2a激酶PERK、GCN2和PKR显示，eIF2a-ATF4报告基因活性依赖于PERK或GCN2。敲低ATF4消除了GSK2606414诱导的呼肠孤病毒蛋白水平的增加，证实eIF2a-ATF信号传导是观察到的表型的关键。我们的工作确定了一种在治疗环境中提高呼肠孤病毒疗效和复制的新方法。
