A Role for AMH Autocrine Signaling in NSCLC

描述（由申请人提供）：本申请的目的是研究我们最近发现的抗苗勒管激素（AMH）在支持侵袭性肺癌转移和耐药特性方面的意外作用。在美国，肺癌每年导致大约160，000人死亡，5年生存率为~ 16%。热休克蛋白90（HSP 90）作为一种分子伴侣蛋白，对支持许多参与肿瘤发生的蛋白质的活性至关重要，并且HSP 90在肿瘤中的过表达与不良结局相关。临床上有前途的HSP 90抑制剂ganetespib在晚期临床试验中显示出相当大的前景，包括NSCLC的临床试验，最近已被授予NSCLC的快速通道状态。我们最初的目标是了解和进一步提高这种和其他HSP 90抑制剂的活性。在对靶向siRNA文库进行广泛筛选后，我们将AMH及其受体AMHRII鉴定为对ganetespib耐药的重要调节剂。AMH是转化生长因子（TGF）-β配体家族的成员，AMHRII与TGF-β和BMP也需要的共受体异二聚化，影响常见的效应级联反应。TGF-β信号传导在NSCLC增殖、存活和转移中的作用已得到充分证实，但之前的研究从未确定AMH和AMHRII在此背景下的作用。我们的初步数据表明，在多种NSCLC细胞系中存在一种涉及AMH和AMHIIR的新的自分泌信号环，并且还表明AMHRII的单克隆抗体使细胞对HSP 90抑制敏感。AMHRII的稳定性最近被证明是高度依赖于HSP 90，而我们已经表明，有显着的表达AMH和AMHRII在肺癌细胞系的子集，以及在许多原发性肺癌。我们假设，以前未检测到的自分泌AMH信号在支持肺癌亚群中的TGF-β通路中起着关键作用，AMH/AMHRII抑制可能增强ganetespib和其他疗法的疗效，AMH和AMHRII可用作肿瘤侵袭性的生物标志物。我们的长期目标是更好地了解AMH和AMHRII在ganetespib和其他药物治疗反应中的作用，并利用这些信息来改善肺癌患者的治疗。在这个提议中，第一个目标将使用siRNA和过表达实验来探测AMH与肺癌细胞中TGF-β信号传导的功能相互作用。第二个目标将探索在体外和体内抑制AMH和AMHRII对药物反应的影响，并使用人肺癌组织微阵列来测量AMH、AMHRII、HSP 90和相关伙伴的表达，作为肿瘤分期、分级和预后的预测因子。

DESCRIPTION (provided by applicant): The goal of this application is to investigate the unexpected role we have recently identified for anti-Müllerian hormone (AMH) in supporting the metastatic and drug resistance properties of aggressive lung cancer. Lung cancer kills approximately 160,000 people in the US annually, with a 5 year survival rate of ~16%. As a chaperone protein, heat shock protein 90 (HSP90) is essential to support the activity of many proteins involved in oncogenesis, and HSP90 overexpression in tumors correlates with worse outcomes. The clinically promising HSP90 inhibitor ganetespib is showing considerable promise in late stage clinical trials, including those for NSCLC, and has recently been granted Fast Track status for NSCLC. Our initial goal was to understand and further improve the activity of this and other HSP90 inhibitors. Following extensive screening of a targeted siRNA library, we identified AMH and its receptor AMHRII as significant regulators of resistance to ganetespib. AMH is a member of the transforming growth factor (TGF)-β ligand family, and AMHRII heterodimerizes with co-receptors also required by TGF-β and BMP, influencing common effector cascades. The role for TGF-β signaling in NSCLC proliferation, survival and metastasis is well established, but no prior study has ever identified a role for AMH and AMHRII in this context. Our preliminary data suggests a novel autocrine-signaling loop involving AMH and AMHIIR in multiple NSCLC cell lines, and also suggest a monoclonal antibody to AMHRII sensitizes cells to HSP90 inhibition. AMHRII stability was recently shown to be highly dependent on HSP90, while we have shown that there is significant expression of AMH and AMHRII in a subset of lung cancer cell lines as well as in many primary lung cancers. We hypothesize that previously undetected autocrine AMH signaling plays a critical role in supporting the TGF-β pathway in a subpopulation of lung cancers, that AMH/AMHRII inhibition may potentiate the efficacy of ganetespib and other therapies, and that AMH and AMHRII may be utilized as biomarkers for tumor aggressiveness. Our long-term goals are to better understand the role of AMH and AMHRII in therapeutic response to ganetespib and other agents, and use this information to improve the treatment of lung cancer patients. In this proposal, the first aim will use siRNA and overexpression experiments to probe the functional interactions of AMH with TGF-β signaling in lung cancer cells. The second aim will explore the in vitro and in vivo effects of inhibiting AMH and AMHRII for drug response, and use tissue microarrays of human lung cancer to gauge expression of AMH, AMHRII, HSP90 and related partners as predictors of tumor stage, grade, and prognosis.