Validating the prognostic value of EGFR768 in neuroblastoma

描述（申请人提供）：神经母细胞瘤（Neuroblastoma， NB）是儿童最常见的颅外实体瘤，占儿童恶性肿瘤的7%以上。尽管进行了积极的治疗，患有高危神经母细胞瘤的儿童的病情仍然很差，只有不到一半的人能存活下来。幸存者还会遭受长期的副作用。迫切需要更有效的靶向治疗。近年来，表皮生长因子受体（EGFR）已成为肿瘤治疗的热门靶点。EGFR抑制剂已在难治性NB患儿中进行了试验。有趣的是，在30 - 40%的患者中观察到部分反应或疾病稳定。由于EGFR突变是对抗EGFR药物反应的生物标志物，我们在62例原发性NB肿瘤中筛选了EGFR突变。我们不仅发现了32%的EGFR缺失突变，而且惊讶地发现了一种新的EGFR细胞外缺失突变，EGFR 768。我们实验室的进一步研究发现，EGFR 768具有组成性活性，对EGFR抑制剂厄洛替尼敏感，并增强癌细胞的生长和侵袭潜力。基于这些EGFR 768的生物学和生化特性，我们提出了以下假设：EGFR 768的表达使神经母细胞瘤患者的无病生存率显著降低。我们计划以以下具体目标来证明这一假设。特定目的：确定表达EGFR 768的神经母细胞瘤是否更具侵袭性通过参与儿童肿瘤组神经母细胞瘤临床试验的患者的原发性NB肿瘤，我们将确定表达EGFR 768的NB是否更有可能属于高风险组，因此5年无病生存期明显较差。这里有两个主题。目的1：单克隆EGFR 768特异性抗体的制备。在本课题中，我们将开发并验证一种独特的分子诊断试剂，用于检测石蜡包埋肿瘤切片上的EGFR¿768突变蛋白。在将该抗体用于结果分析之前，将对其敏感性和特异性进行严格测试。Subaim II：生存分析。在本课题中，我们将通过临床生物学相关性来确定EGFR¿768在NB中是否具有预后价值。本项目评估EGFR¿768作为神经母细胞瘤的预后生物标志物。如果成功，不仅将确定一种新的神经母细胞瘤预测因子，而且这种突变体也有可能成为新的治疗靶点。因此，EGFR¿768特异性诊断试剂的开发将允许在临床标本中快速识别这种突变体，并有可能推进神经母细胞瘤患者的个性化抗EGFR治疗，从而改善结果并最大限度地减少当前治疗的副作用。

DESCRIPTION (provided by applicant): Neuroblastoma (NB) is the most common extracranial solid tumor of childhood and accounts for more than 7% of childhood malignancies. Despite aggressive therapy, children with high risk neuroblastoma still fare poorly with less than half surviving the disease. The survivors also suffer long term side effects. More effective targeted therapy is urgently needed. Epidermal growth factor receptor (EGFR) has become a popular target for cancer therapy in recent years. EGFR inhibitors have been tested in children with refractory NB. Interestingly, partial response or stable disease was observed in 30 - 40% of these patients. Since EGFR mutations are biomarkers for response to anti-EGFR drugs, we screened for EGFR mutations in 62 primary NB tumors. We not only found that 32% expressed deletion mutations of EGFR, but were surprised to discover a novel EGFR extracellular deletion mutant, EGFR 768. Further studies in our laboratory found that EGFR 768 is constitutively active, confers sensitivity to the EGFR inhibitor, erlotinib, and enhances the growth as well as invasive potential of cancer cells. Based on these biological and biochemical properties of EGFR 768, we formulated the following hypothesis: EGFR 768 expression confers a significantly worse disease free survival in neuroblastoma patients. We plan to prove this hypothesis with the following specific aim. Specific Aim: Determine if neuroblastoma that express EGFR 768 are more aggressive Using primary NB tumors accrued from patients who participated in the Children's Oncology Group neuroblastoma clinical trials, we will determine if NB that expressed EGFR¿768 are more likely to be in the high risk group and therefore have a significantly worse 5 year disease free survival. There are two subaims. Subaim I: Production of a monoclonal EGFR 768 specific antibody. In this subaim, we will develop and validate an unique molecular diagnostic reagent to detect the EGFR¿768 mutant protein on paraffin embedded tumor sections. The sensitivity and specificity of this antibody will be vigorously tested before using it for the outcome analysis. Subaim II: Survival analysis. In this subaim, we will perform clinical biological correlation to determine if EGFR¿768 has prognostic value in NB. This project evaluates EGFR¿768 as a prognostic biomarker for neuroblastoma. If successful, not only will a new neuroblastoma prognosticator be identified, but there is a potential for this mutant to be a new therapeutic target as well. Thus, the development of a EGFR¿768 specific diagnostic reagent will allow for rapid identification of this mutant in clinical specimen and has the potential to advance personalized anti-EGFR therapy for neuroblastoma patients, thereby improving the outcome and minimizing the side effects of the current therapy.