Peroxiredoxin 1 in radiotherapy of lung cancer

过氧化还原蛋白1在肺癌放疗中的应用

• 批准号: 6814987
• 负责人: YOUNG-MEE PARK
• 金额: $ 24.96万
• 依托单位: ROSWELL PARK CANCER INSTITUTE CORP
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6814987
• 关键词: antineoplastics; antioxidants; apoptosis; cell proliferation; clinical research; free radical oxygen; gel mobility shift assay; gene expression; human tissue; lung neoplasms; neoplasm /cancer genetics; neoplasm /cancer radiation therapy; neoplastic process; oxidation reduction reaction; oxidative stress; polymerase chain reaction; redoxin; site directed mutagenesis; transcription factor

DESCRIPTION (provided by applicant): Radiotherapy remains the major treatment modality for lung cancer. The therapeutic effect of radiation is primarily mediated by the generation of reactive oxygen species (ROS) and ROS-driven oxidative stress. Peroxiredoxins (Prxs) are an expanding family of antioxidant proteins. Prxs are expressed at high levels in all cells and constitute 0.1-0.8% of the soluble protein in mammalian cells. Two highly homologous members of this protein family, Prx1 and Prx2, have been shown to affect cell proliferation/apoptosis and increase the therapy resistance of cancer cells. Most studies to date have been restricted to observations of the elevated expression of Prxs in various cultured cell systems and some human tissues. However, the effects of Prx expression in human cancers, their influence on cancer therapy, and the regulatory basis for their expression in cancer have not been well investigated. The research proposed in this application emanates from our recent studies of Prx1 and Prx2 function and expression in human lung cancer. First, the expression profiles of Prx1 and Prx2 are clearly distinct in human lung cancer tissues. While Prx1 is significantly elevated in lung cancer cells, Prx2 is not and appears to be primarily expressed in the vascular endothelial cells of the tumor periphery. Second, we have found that the upstream regulatory regions of Prx1 and Prx2 display striking differences and that the levels of Prx1 message are much greater than of Prx2 in various human lung cancer cell lines. Thirdly, the expression of Prx1, but not Prx2, is up regulated at the message level in human lung cancer cells by oxidative stress-inducing conditions including exposure to ionizing radiation. Lastly, our studies have shown that over-expression of Prx1 in human lung cancer cells leads to an increase in clonogenic survival and a reduction in apoptosis in vitro following radiation treatment. These findings led us to postulate that Prx1 may possess unique functions and regulatory mechanisms in human lung cancer. Our hypothesis is that environmental and pathophysiological ROS and ROS-driven oxidative stress increase the level of Prx1 expression by activating redox-sensitive transcription factors and that Prx1 provides a cell survival advantage, in part by directly reducing ROS levels and oxidative damage and also by its ability to control the oxidation/function of redox-sensitive molecules that mediate cell proliferation/apoptosis. We propose 4 Specific Aims to test this hypothesis. In Aim 1, we will determine the functional consequences of Prx1 elevation and its potential role in the radiation resistance of human lung cancer. In Aim 2, we will investigate the regulatory mechanisms for the inducible regulation of Prx1 expression by radiation. In Aim 3, we will identify important redox-sensitive target/effector molecules that might mediate Prx1 function in response to radiation. In a translational extension of the above aims, we will test the predictive value of Prx1 in progression and therapy response of lung cancer in Aim 4 using human lung cancer specimen. In summary, the proposed research is highly translational in nature yet addresses important scientific questions on the role of Prx1 in the radiotherapy of lung cancer. These studies will define the role of Prx1 in the radiotherapy of lung cancer and provide a sound scientific basis upon which the regulation and function of Prx1 in lung cancer cell survival and radioresistance can be evaluated in lung cancer and other human malignancies.

描述(申请人提供)：放射治疗仍然是肺癌的主要治疗方式。辐射的治疗作用主要是通过产生活性氧(ROS)和ROS驱动的氧化应激来实现的。过氧化还蛋白(Peroxiredoxins，Prxs)是一个不断扩大的抗氧化蛋白家族。Prxs在所有细胞中都有高水平的表达，占哺乳动物细胞中可溶性蛋白的0.1-0.8%。该蛋白家族的两个高度同源的成员，Prx1和Prx2，已被证明影响细胞的增殖和凋亡，并增加肿瘤细胞的治疗耐药性。到目前为止，大多数研究都局限于观察Prxs在各种培养细胞系统和一些人类组织中的表达升高。然而，PRX在人类癌症中的表达及其对癌症治疗的影响，以及它们在癌症中表达的调控基础还没有得到很好的研究。 本申请中提出的研究源于我们最近对Prx1和Prx2在人类肺癌中的功能和表达的研究。首先，Prx1和Prx2在人肺癌组织中的表达谱明显不同。虽然Prx1在肺癌细胞中显著升高，但Prx2不表达，似乎主要表达于肿瘤周围的血管内皮细胞。第二，我们发现在不同的人肺癌细胞系中，PrX1和Prx2的上游调控区表现出显著的差异，并且PRX1的消息水平远远大于Prx2的水平。第三，在包括暴露于电离辐射在内的氧化应激诱导条件下，Prx1而不是Prx2的表达在人类肺癌细胞的信息水平上被上调。最后，我们的研究表明，在放射治疗后，PRX1在人肺癌细胞中的过表达导致体外克隆形成生存率的增加和细胞凋亡的减少。这些发现使我们推测PRX1可能在人类肺癌中具有独特的功能和调节机制。 我们的假设是，环境和病理生理学的ROS和ROS驱动的氧化应激通过激活氧化还原敏感的转录因子来增加PRX1的表达水平，并且PRX1提供了细胞生存的优势，部分是通过直接降低ROS水平和氧化损伤，以及它控制介导细胞增殖/凋亡的氧化还原敏感分子的氧化/功能的能力。我们提出了4个具体目标来检验这一假说。在目标1中，我们将确定PRX1上调的功能后果及其在人类肺癌放射抵抗中的潜在作用。在目标2中，我们将研究辐射对PRX1表达的诱导调控机制。在目标3中，我们将识别重要的氧化还原敏感靶分子/效应分子，它们可能介导PRX1对辐射的反应。在上述目标的翻译扩展中，我们将使用人肺癌标本来检验PRX1在目标4中对肺癌进展和治疗反应的预测价值。 总而言之，这项拟议的研究本质上是高度翻译的，但解决了关于PRX1在肺癌放射治疗中的作用的重要科学问题。这些研究将明确PRX1在肺癌放射治疗中的作用，并为评价PRX1在肺癌和其他人类恶性肿瘤中对肺癌细胞存活和辐射耐药的调控和功能提供可靠的科学依据。