Iskandar Kartini, Rezlan Majidah, Yadav Sanjiv Kumar, Foo Chuan Han Jonathan, Sethi Gautam, Qiang Yu, Bellot Gregory L, Pervaiz Shazib
1 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore, Singapore .
2 Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore, Singapore .
Antioxid Redox Signal. 2016 May 10;24(14):781-94. doi: 10.1089/ars.2015.6362. Epub 2016 Feb 26.
We recently reported the death-inducing activity of a small-molecule compound, C1, which triggered reactive oxygen species (ROS)-dependent autophagy-associated apoptosis in a variety of human cancer cell lines. In this study, we examine the ability of the compound to specifically target cancer cells harboring mutant KRAS with minimal activity against wild-type (WT) RAS-expressing cells.
HCT116 cells expressing mutated KRAS are susceptible, while the WT-expressing HT29 cells are resistant. Interestingly, C1 triggers activation of mutant RAS, which results in the downstream phosphorylation and activation of AKT/PKB. Gene knockdown of KRAS or AKT or their pharmacological inhibition resulted in the abrogation of C1-induced ROS production and rescued tumor colony-forming ability. We also made use of HCT116 mutant KRAS knockout (KO) cells, which express only a single WT KRAS allele. Exposure of KO cells to C1 failed to increase mitochondrial ROS and cell death, unlike the parental cells harboring mutant KRAS. Similarly, mutant KRAS-transformed prostate epithelial cells (RWPE-1-RAS) were more sensitive to the ROS-producing and death-inducing effects of C1 than the vector only expressing RWPE-1 cells. An in vivo model of xenograft tumors generated with HCT116 KRAS(WT/MUT) or KRAS(WT/-) cells showed the efficacy of C1 treatment and its ability to affect the relative mitotic index in tumors harboring KRAS mutant.
These data indicate a synthetic lethal effect against cells carrying mutant KRAS, which could have therapeutic implications given the paucity of KRAS-specific chemotherapeutic strategies. Antioxid. Redox Signal. 24, 781-794.
我们最近报道了一种小分子化合物C1的促死亡活性，它在多种人类癌细胞系中引发了活性氧（ROS）依赖性自噬相关凋亡。在本研究中，我们检测了该化合物特异性靶向携带突变型KRAS的癌细胞的能力，而对表达野生型（WT）RAS的细胞活性最小。
表达突变型KRAS的HCT116细胞敏感，而表达WT的HT29细胞耐药。有趣的是，C1触发了突变型RAS的激活，导致下游AKT/PKB的磷酸化和激活。KRAS或AKT的基因敲低或其药理学抑制导致C1诱导的ROS产生被消除，并挽救了肿瘤集落形成能力。我们还利用了仅表达单个WT KRAS等位基因的HCT116突变型KRAS敲除（KO）细胞。与携带突变型KRAS的亲代细胞不同，将KO细胞暴露于C1未能增加线粒体ROS和细胞死亡。同样，突变型KRAS转化的前列腺上皮细胞（RWPE-1-RAS）比仅表达载体的RWPE-1细胞对C1的ROS产生和促死亡作用更敏感。用HCT116 KRAS(WT/MUT)或KRAS(WT/-)细胞生成的异种移植肿瘤体内模型显示了C1治疗的疗效及其影响携带KRAS突变的肿瘤中相对有丝分裂指数的能力。
这些数据表明对携带突变型KRAS的细胞具有合成致死效应，鉴于KRAS特异性化疗策略的匮乏，这可能具有治疗意义。《抗氧化与氧化还原信号》24, 781 - 794。
