Redox modulation - Impact on Tumor Growth and Therapeutic Anticancer Efficacy

尽管癌症生物学取得了进展，但耐药性仍然是患者和临床医生的主要障碍。许多当前 癌症治疗部分地通过提高活性氧（ROS）的产生来起作用， 消退，随后是肿瘤复发和治疗抗性。以前，Kelkka和同事们看起来 在具有缺乏来自蛋白质NOX 2的ROS的巨噬细胞的小鼠中的肿瘤进展（Kelkka等人，2013年）。 他们的结论是，当ROS释放时，免疫细胞对转移和肿瘤进展更有效。 巨噬细胞中的产生被抑制。另一方面，其他人已经证明了 致癌和我们的先天抗氧化系统，如硫氧还蛋白还原酶（TrxR）系统和 谷胱甘肽还原酶系统（Gorrini等，2013年）。随着癌变的进展，细胞产生越来越多的 的ROS。肿瘤细胞通过适应性抗氧化反应如硫氧还蛋白来应对高水平的ROS 还原酶系统然而，当该系统在肿瘤细胞内受损时，体内肿瘤进展和 转移可被显著抑制（Yoo等，2006年）。 鉴于这些发现，我们认为肿瘤细胞对目前的治疗产生耐药性，部分原因是系统性的， ROS产生的增加，其1）由于肿瘤细胞的适应性生长而不足以促进肿瘤细胞的细胞死亡， 抗氧化反应，和2）ROS水平升高损害免疫细胞有效对抗肿瘤细胞。 因此，我们建议，一个联合的方法是需要有效的抗癌治疗。我们假设 具有功能失调的抗氧化系统的肿瘤细胞将显著退化， 在低ROS条件下，将启动免疫应答以根除剩余的恶性肿瘤。 这个博士项目的重点是研究这一假设和表征最佳氧化还原 肿瘤消退的条件。我们计划使用两种成熟的小鼠肿瘤模型来实现这一点：1） 转移性B16 F10黑色素瘤和2）转移性刘易斯肺癌，LLC 1。我们将描述在 在这些肿瘤模型中的体外基线氧化还原系统，使用siRNA或CRISPR进行改变。我们还将 看看肿瘤在活体中的发展。我们将使用六种小鼠品系来帮助我们理解 宿主氧化还原生物学，在免疫细胞和系统，在应对癌症。具体来说，我们将使用 具有关键表型的小鼠模型：B6.129P2-Txnrd1tm1Marc、B6.129P2-Txnrd1Cond、BQ.Ncf1m1J（Ncf1突变体 小鼠）、BQ.Ncf4（Ncf4突变小鼠）、BQMN（仅在巨噬细胞中表达Ncf1）和BQ.TN3 条件性基因敲入小鼠。最后，我们将研究肿瘤氧化还原系统与金诺芬和其他挑战， TrxR1抑制剂。

Despite advances in cancer biology, drug resistance is a major obstacle to patients and clinicians. Many current cancer therapeutics work in part by elevating reactive oxygen species (ROS) production, often leading to tumor regression followed by tumor reoccurrence and therapeutic resistance. Previously, Kelkka and coworkers looked at tumor progression in mice with macrophages deficient in ROS from the protein NOX2 (Kelkka et al., 2013). They concluded that immune cells are more efficacious against metastasis and tumor progression when ROS production in macrophages is inhibited. On the other hand, others have demonstrated the relationship between carcinogenesis and our innate antioxidant systems such as the thioredoxin reductase (TrxR) system and the glutathione reductase system (Gorrini et al., 2013). As carcinogenesis progress, cells produce increasing levels of ROS. Tumor cells cope with high levels ROS via an adaptive antioxidant response such as the thioredoxin reductase system. However, when this system is impaired within tumor cells, in vivo tumor progression and metastasis may be significantly inhibited (Yoo et al., 2006). Given these findings, we believe that tumor cells become resistant to current therapies in part by the systemic increase of ROS production, which 1) is insufficient to promote cell death in tumor cells because of their adaptive antioxidant response, and 2) elevated levels of ROS impairs immune cells from effectively combating tumor cells. Therefore we propose that a combined approach is required for effective anticancer therapy. We hypothesize that tumor cells with dysfunctional antioxidant systems will significantly regress and that the host’s immune response, under low ROS conditions, will be primed to eradicate the remaining malignancy. The focus of this proposed PhD project is to investigate this hypothesis and characterize the optimal Redox conditions for tumor regression. We plan to accomplish this using two well-established murine tumor models: 1) the metastatic B16F10 melanoma and 2) the metastatic Lewis Lung Carcinoma, LLC1. We will characterize in vitro the baseline Redox systems in these tumor models, make alterations using siRNA or CRISPR. We will also look at tumor progression in living hosts. We will use six mouse strains to help us understand the significance of host Redox biology, in both the immune cells and systemically, in response to cancer. Specifically, we will use mouse models with key phenotypes: B6.129P2-Txnrd1tm1Marc, B6.129P2-Txnrd1Cond, BQ.Ncf1m1J (Ncf1 mutant mice), BQ.Ncf4 (Ncf4 mutant mice), BQMN (expressing Ncf1 in macrophages only) and BQ.TN3 conditional knock-in mice. Finally, we will study tumor redox systems challenged with Auranofin and other TrxR1 inhibitors.