Targeting FGFR to prevent the outgrowth of metastatic breast cancer

求职者：作为一名研究生和博士后研究员，我完成了关于癌症生长和进展到转移的许多方面的综合研究项目。我目前是由美国癌症协会的博士后奖学金资助的。在过去的六年里，我的生产率一直很高，导致了影响很大的手稿的持续出版。我目前担任这一职位 高级研究助理，凯斯西储大学博士后培训级别最高的。在收到并执行这份申请的指导阶段后，我的最终目标是在一流的大学或研究机构运行一个富有成效和活力的独立研究项目。 环境：凯斯综合癌症中心内的研究和核心设施是首屈一指的。在这种环境下，我将能够在基础研究、临床前研究和临床研究之间无缝过渡。特别是在希曼实验室，我一直接受并将继续接受研究技术、赠款和手稿准备、演示技能和研究管理方面的特别培训。此外，在准备这份申请的过程中，我利用了重要的智力资源 在病例综合癌症中心。我从许多高水平的研究人员那里寻求建议和指导，他们的意见帮助我构建了一个有重点的和临床相关的建议。这种独特的培训将使我在过渡到独立调查员的过程中脱颖而出。 研究：乳腺癌确诊为晚期转移性疾病五年存活率骤降事实上，目前的治疗方法在减少转移性乳腺癌的生长方面无效，这表明驱动转移性生长的分子途径发生了根本性的变化，而不是原发肿瘤的生长。根据定义，三阴性乳腺癌(TNBC)缺乏激素(雌激素和孕激素受体)和Her2靶向治疗所需的靶点。在TNBC的背景下，原发肿瘤中EGFR表达的增强与疾病预后的降低密切相关，这表明EGFR是治疗TNBC的有效靶点。然而，EGFR靶向化疗并不能为TNBC患者提供临床益处。EGFR的诊断价值和EGFRi治疗的临床失败之间的脱节强烈表明，在晚期肿瘤复发和转移过程中，TNBCs获得了替代的促生长信号通路。伴随着疾病复发和转移的是上皮-间充质转化(EMT)。尽管最近在阐明细胞从上皮细胞向间充质状态转变的分子机制方面取得了进展，但对EMT导致的分子信号通路的具体变化知之甚少。EGFR的配体刺激导致丝裂原活化蛋白激酶(MAPK)和信号转导与转录激活因子3(STAT3)通路的强烈激活，但EMT如何影响这些信号通路尚不清楚。在第一个目标中，我们认为EMT的异常启动通过导致EGFR功能从增殖到侵袭的根本切换来促进乳腺肿瘤细胞从原发灶扩散。我们进一步提出，这种功能的切换需要失去EGFR介导的STAT3激活。为了解决这一假设，我们将使用遗传和药理学方法来调节STAT3的表达和/或活性，并评估这些STAT3修饰对EMT促进乳腺癌生长和转移能力的影响。此外，我们将使用一种新的双底物生物发光技术来实时跟踪原位乳腺肿瘤生长和转移时体内STAT3的活性。作为EMT介导的EGFR功能转换的结果，在全身扩散之后，必须上调其他生长因子信号通路，以促进转移生长。基于我们的初步数据，在目标2中，我们将提出这样的假设，即成纤维细胞生长因子受体(FGFR)的上调能够取代EGFR成为TNBC转移生长过程中主要的有丝分裂信号模块。这种生长因子依赖从EGF转变为成纤维细胞生长因子提供了一种可能的机制，即复发和转移的TNBC不受EGFR靶向治疗的影响。因此，我们将使用遗传学和药理学方法来靶向FGFR，并有效地抑制复发和转移的TNBC病变。最后，在Aim3中，我们将使用一种新的插入突变技术来筛选EGFRi不敏感的潜在介质。此外，我们将从功能上表征FGFR和Tensin1的诊断潜力，这两个成员是我们最近建立的EGFRi不敏感的12基因标记。我们将利用已知诊断、治疗和结果的人类乳腺癌样本来建立一个诊断平台，该平台将识别最有可能对FGFRi治疗有反应的TNBC患者。总体而言，拟议的研究将解决目前关于EMT将促进TNBC生长的信号从EGFR进化到FGFR的分子机制的知识空白，从而导致EGFR靶向药物在治疗晚期TNBC方面失败。更重要的是，我们的研究将建立一个诊断平台和治疗方案，以抑制FGFR作为TNBC患者转移性肿瘤复发的有效治疗选择。

DESCRIPTION (provided by applicant): Candidate: As a graduate student and postdoctoral fellow I have completed comprehensive research projects concerning numerous aspects of cancer growth and progression to metastasis. I am currently funded by a postdoctoral fellowship from the American Cancer Society. My productivity rate has been very strong for the last six years resulting in consistent publication of high impact manuscripts. I currently hold the position of Senior Research Associate, the highest postdoctoral training rank at Case Western Reserve University. Subsequent to receipt and execution of the mentored phase of this application my ultimate goal is run a productive and dynamic independent research program at a leading university or research institute. Environment: The research and core facilities within the Case Comprehensive Cancer Center are second to none. Within this environment I will be able to seamlessly transition between basic, pre-clinical and clinical research. Within the Schiemann laboratory in particular I have been and will continue to receive extraordinary training in research technique, grant and manuscript preparation, presentation skills, and research management. Furthermore, through the process of preparing this application I have tapped into the significant intellectual resources within the Case Comprehensive Cancer Center. I have sought out advice and guidance from numerous high level investigators whose input has aided me in constructing a focused and clinically relevant proposal. This unique training will set me apart as I transition into an independent investigator. Research: The five-year survival rate of breast cancer drops precipitously when diagnosed as late stage metastatic disease. Indeed, current therapies are ineffective at reducing the growth of metastatic breast cancer suggesting that there is a fundamental change in the molecular pathways that drive metastatic outgrowth as opposed to primary tumor growth. By definition triple negative breast cancers (TNBC) lack the required targets of hormonal (estrogen and progesterone receptors) and Her2-targeted therapies. In the context of TNBC, enhanced expression of EGFR within the primary tumor is strongly linked to decreased disease prognosis, suggesting EGFR as an effective target in treating TNBC. However, EGFR-targeted chemotherapies do not offer clinical benefit to TNBC patients. This disconnect between the diagnostic value of EGFR and the clinical failure of EGFRi therapies strongly suggests that TNBCs acquire alternate growth promoting signaling pathways during late-stage tumor recurrence and metastasis. Concomitant with disease recurrence and metastasis is the acquisition of epithelial-mesenchymal transition (EMT). Despite recent advances in elucidating the molecular players involved in the conversion of cells from an epithelial to mesenchymal state, little is known about the specific changes in molecular signaling pathways that result as a consequence of EMT. Ligand stimulation of EGFR leads to the robust activation of both mitogen activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (Stat3) pathways, but how these signaling pathways are affected by EMT remains unexplored. In the first Aim we propose that aberrant initiation of EMT facilitates mammary tumor cell dissemination from the primary lesion by causing a fundamental switch in EGFR function from proliferation to invasion. We further propose that this switch in function requires the loss of EGFR-mediated Stat3 activation. To address this hypothesis we will use genetic and pharmacological approaches to modulate Stat3 expression and/or activity, and assess the impact of these Stat3 modifications on the ability of EMT to enhance breast cancer growth and metastasis. Furthermore, we will employ a novel dual- substrate bioluminescence technique to track real-time in vivo Stat3 activity as orthotopic mammary tumors grow and metastasize. As a consequence of the EMT-mediated switch in EGFR function, following systemic dissemination, other growth factor signaling pathways must be upregulated to facilitate metastatic outgrowth. Based on our preliminary data, in Aim 2 we will address the hypothesis that upregulation of fibroblast growth factor receptor (FGFR) is capable of replacing EGFR as the dominant mitogenic signaling module during metastatic outgrowth of TNBC. This switch in growth factor dependence from EGF to FGF presents a plausible mechanism by which recurrent and metastatic TNBC is unaffected EGFR-targeted therapies. Therefore, we will use genetic and pharmacological approaches to target FGFR and effectively inhibit recurrent and metastatic TNBC lesions. Finally, in Aim3 we will use a novel insertional mutagenesis technique to screen for potential mediators of EGFRi-insensitivity. In addition we will functionally characterize the diagnostic potential of FGFR and Tensin1 two members of our recently established 12-gene signature of EGFRi-insensitivity. We will utilize human breast cancer specimens of known diagnosis, treatment, and outcome to establish a diagnostic platform that would identify TNBC patients most likely to respond to FGFRi therapy. Overall, the proposed studies will address current gaps in knowledge concerning the molecular mechanisms by which EMT evolves TNBC growth promoting signaling from EGFR to FGFR, leading to the failure of EGFR-targeting agents in treating late-stage TNBC. More importantly, our studies will establish a diagnostic platform and therapeutic protocol for the inhibition of FGFR as an effective treatment option for TNBC patients undergoing metastatic tumor recurrence.