EGFR PATHWAY ALTERATIONS IN LUNG TUMORS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。拟议的研究项目利用了有毒金属研究、肺癌发生方面的现有机构优势，并建立在目前的肺部科布雷项目的基础上。具体地说，这项建议为安德鲁·S博士带来了广泛的镍毒学和分子流行病学研究经验，以及科布雷项目4中空气颗粒物镍的监测工作、通过一项新的肺癌病例对照研究(科布雷项目5)收集的暴露信息和生物样本，以及德米特罗夫斯基团队？S在通过分子表征和临床试验获得的表皮生长因子受体途径方面的专业知识。研究背景在动物实验中，表皮生长因子受体(EGFR)的过度表达常见于肺癌和支气管癌前病变中，并诱导肿瘤的形成。EGFR调节细胞存活、细胞周期进程、肿瘤侵袭和血管生成。在以前的工作中，利用临床材料，EGFR在体外和体内都影响了常见的下游细胞周期调节因子细胞周期蛋白D1的表达。EGFR酪氨酸激酶抑制剂(EGFR-TKI)的治疗效果已经在临床试验中观察到，这些试验旨在通过阻断EGFR激活来治疗非小细胞肺癌(NSCLC)。然而，这些EGFR-TKI临床试验清楚地表明，患者之间的反应性差异很大，可靠的预测因素尚未确定或验证。尽管这一途径具有重要的临床意义，但导致EGFR改变的具体因素仍然很大程度上是未知的。具体地说，EGFR酪氨酸激酶域中未知环境来源的体细胞突变与EGFR-TKI疗效密切相关，并且在不吸烟的人中突变率更高。假设-作为一种令人担忧的遗传毒性、致突变和致癌金属，我们假设通过吸入空气颗粒物而暴露于镍会改变EGFR信号和/或促进EGFR基因的突变。以前的研究和我们自己的初步数据表明，镍诱导细胞培养中EGFR的表达[Mollerup，1996#5129]。我们建议在两个实验系统中研究镍在EGFR途径调节中的作用：1)使用BEAS2B人肺上皮细胞系进行细胞培养，2)从早期非小细胞肺癌患者的肿瘤标本中获得。相关性--这些研究将为空气污染中促进肺癌发生的特定成分(例如镍)提供新的机械性见解。确定影响EGFR信号通路的暴露的特征将有助于优化靶向筛查和分子诊断的使用。然后，我们可以确定潜在反应性病例的亚组，以及谁将受益于作为肺部治疗策略的药物EGFR抑制。具体目的：1)评价有毒金属(砷、镍)暴露是否与A)EGFR TK结构域体细胞激活突变B)EGFR、p-EGFR、细胞周期蛋白D1蛋白水平有关；2)探讨EGFR、细胞周期蛋白D1基因多态性对EGFR途径蛋白水平和肺癌风险的影响。EGFR SNPs稳定细胞周期蛋白D1基因变异3)验证靶向EGFR和细胞周期蛋白D1共同调节p-EGFR和细胞周期蛋白D1EGFR突变的临床策略与联合治疗的临床反应

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The proposed research project capitalizes on existing institutional strengths in toxic metals research, lung carcinogenesis, and builds on the current lung COBRE projects. Specifically, this proposal brings Dr. Andrew¿s extensive nickel toxicology and molecular epidemiology research experience together with the airborne particulate matter nickel monitoring efforts of COBRE Project 4, exposure information and biologic samples collected through a new lung cancer case-control study (COBRE Project 5), and the Dmitrovsky group¿s expertise in the epidermal growth factor receptor (EGFR) pathway obtained through molecular characterization and clinical trials. Background ¿ Epidermal growth factor receptor (EGFR) over-expression is frequently observed in lung tumors and bronchial pre-neoplasia and induces tumor formation in animal studies. EGFR regulates cell survival, cell-cycle progression, tumor invasion, and angiogenesis. In previous work, EGFR affected expression of the common downstream cell cycle regulator, cyclin D1 both in vitro and in vivo using clinical material. Therapeutic efficacy with EGFR tyrosine kinase inhibitors (EGFR-TKI) is already being observed in clinical trials that aim to treat non-small cell lung cancer (NSCLC) by blocking EGFR activation. Yet, these EGFR-TKI clinical trials clearly show that responsiveness between patients varies dramatically, and reliable predictors have not been identified or validated. Despite the clinical importance of this pathway, those specific factors that cause alterations in EGFR remain largely unknown. Specifically, somatic mutations of unknown environmental origin in the EGFR tyrosine kinase domain correlated tightly with EGFR-TKI efficacy and the mutation rate was higher in non-smokers. Hypothesis - As a genotoxic, mutagenic and carcinogenic metal of concern, we hypothesize that nickel exposure via inhalation of airborne particulate matter alters EGFR signaling and or promotes mutations in the EGFR gene. Previous studies and our own preliminary data suggest that nickel induces EGFR expression in cell culture [Mollerup, 1996 #5129]. We propose to investigate the role of nickel in EGFR pathway regulation in two experimental systems: 1) in cell culture using the BEAS2B human lung epithelial cell lines, and 2) in tumor specimens obtained from early stage non-small cell lung cancer cases. Relevance - These studies will provide new mechanistic insights into specific components of air pollution (e.g. nickel) that promote lung carcinogenesis. Characterizing an exposure that impacts the EGFR signaling pathway will help optimize use of targeted screening and molecular diagnostics. We can then identify subsets of potentially responsive cases and who will benefit from pharmacologic EGFR inhibition as a therapeutic strategy in the lung. Specific Aims: 1) To evaluate whether toxic metal (arsenic, nickel) exposure is associated with A) EGFR TK domain somatic activating mutations B) EGFR, p-EGFR, cyclin D1 protein levels 2) To investigate the effect of EGFR, cyclin D1 genetic polymorphisms on EGFR pathway protein levels and lung cancer risk. EGFR SNPs a stabilizing cyclin D1 genetic variation 3) To validate the clinical strategy of targeting EGFR and cyclin D1 Co-regulation of p-EGFR and cyclin D1 EGFR mutations vs. clinical response to combination therapy