Ríos-Arrabal Sandra, Artacho-Cordón Francisco, León Josefa, Román-Marinetto Elisa, Del Mar Salinas-Asensio María, Calvente Irene, Núñez Maria Isabel
Departamento de Radiología y Medicina Física, Universidad de Granada, Av. Madrid s/n, 18012 Granada, Spain.
Springerplus. 2013 Aug 27;2:404. doi: 10.1186/2193-1801-2-404.
Researchers have recently shown an increased interest in free radicals and their role in the tumor microenvironment. Free radicals are molecules with high instability and reactivity due to the presence of an odd number of electrons in the outermost orbit of their atoms. Free radicals include reactive oxygen and nitrogen species, which are key players in the initiation and progression of tumor cells and enhance their metastatic potential. In fact, they are now considered a hallmark of cancer. However, both reactive species may contribute to improve the outcomes of radiotherapy in cancer patients. Besides, high levels of reactive oxygen species may be indicators of genotoxic damage in non-irradiated normal tissues. The purpose of this article is to review recent research on free radicals and carcinogenesis in order to understand the pathways that contribute to tumor malignancy. This review outlines the involvement of free radicals in relevant cellular events, including their effects on genetic instability through (growth factors and tumor suppressor genes, their enhancement of mitogenic signals, and their participation in cell remodeling, proliferation, senescence, apoptosis, and autophagy processes; the possible relationship between free radicals and inflammation is also explored. This knowledge is crucial for evaluating the relevance of free radicals as therapeutic targets in cancer.
研究人员最近对自由基及其在肿瘤微环境中的作用表现出了越来越浓厚的兴趣。自由基是由于其原子最外层轨道存在奇数个电子而具有高不稳定性和高反应性的分子。自由基包括活性氧和活性氮物种，它们是肿瘤细胞起始和进展的关键参与者，并增强其转移潜能。事实上，它们现在被认为是癌症的一个标志。然而，这两种活性物种都可能有助于改善癌症患者的放疗效果。此外，高水平的活性氧物种可能是非照射正常组织中遗传毒性损伤的指标。本文的目的是综述自由基与致癌作用的最新研究，以了解导致肿瘤恶性程度的途径。本综述概述了自由基在相关细胞事件中的参与情况，包括它们通过生长因子和肿瘤抑制基因对遗传不稳定性的影响、它们对促有丝分裂信号的增强作用以及它们参与细胞重塑、增殖、衰老、凋亡和自噬过程；还探讨了自由基与炎症之间的可能关系。这些知识对于评估自由基作为癌症治疗靶点的相关性至关重要。
