Gene Expression of Neuroblastoma and Normal Cells in Bone Marrow Predicts Outcome

描述（由申请人提供）：项目摘要/摘要尽管在过去的20年中，高危转移性神经母细胞瘤儿童的治疗有了显著改善，但只有45%的患者成为长期无病生存者，骨髓是耐药或复发性疾病的常见部位。生存期的改善需要开发有效的新疗法，以生物风险分层的患者亚组为目标，还需要开发有效的生物标志物测定法，以评估缓解并提供长期治疗获益的替代物。具体目标：1）确定与免疫细胞学和临床评价相比，用TaqMan（R）低密度阵列（TLDA）测定5种神经母细胞瘤相关基因定量骨髓和血液中的“肿瘤负荷”是否改善了反应评价和结果预测。2)确定骨髓和血液“微环境”基因表达特征是否可预测结果，以及将这些与肿瘤负荷数据相结合是否可进一步改善结果的预测。3)确定将血液和骨髓的TLDA肿瘤负荷/微环境测定和同一患者原发性肿瘤的TLDA预测性基因表达测定的数据相结合，与单独使用任一测定相比，是否可改善结局预测。研究设计和方法：我们开发了一种新的TLDA检测方法，可以同时定量5个神经母细胞瘤基因（“肿瘤负荷”）和38个代表正常血液和骨髓细胞的“微环境”基因的表达。该测定定量CHGA、DCX、DDC、PHOX 2B和TH的表达，使得可以在106个正常骨髓或血液单核细胞中鉴定一个肿瘤细胞。初步研究表明，PBSC和骨髓中的“肿瘤负荷”与结果相关，其中免疫细胞学检测不到肿瘤细胞。在一个单独资助的项目中，我们开发了另一种TLDA检测方法，该方法可以量化原发性MYCN非扩增肿瘤中的预后14基因表达特征，以预测结果，另一种特征正在开发用于MYCN扩增肿瘤。我们将通过测试来自三个独立队列患者的3，000份可行的冷冻保存标本（所有标本均已通过免疫细胞学检测）来扩展和验证我们的初步研究，这些患者已经/正在参加儿童肿瘤学组的六项不同研究。与免疫细胞学和标准临床评估相比，在评价缓解和预测结局时，分析将考虑标本获取时间（诊断和治疗期间及治疗结束时）和治疗（诱导、巩固和巩固后治疗）。血液和骨髓的肿瘤负荷和微环境数据将与原发性肿瘤的基因表达特征数据相结合，以确定它们之间的关系及其改善临床决策结果预测的能力。总结：预计我们新的骨髓和血液中神经母细胞瘤细胞的TLDA检测将改善预后预测，从而为高危转移性神经母细胞瘤患者开发更有效的治疗方法。 公共卫生相关性：尽管在过去的20年里，高危转移性神经母细胞瘤（4期）儿童的治疗水平稳步提高，但只有45%的患者长期存活，骨髓是耐药或复发性疾病的常见部位。我们已经开发了一种稳健的生物标志物测定法，该测定法通过肿瘤细胞基因的表达同时定量“肿瘤负荷”和通过正常骨髓和血细胞基因的表达定量“微环境”。我们预计，这种检测将成为一个不可或缺的生物标志物工具，用于评估对新的治疗策略的反应，并预测高危神经母细胞瘤儿童的结局。

DESCRIPTION (provided by applicant): Project Summary/Abstract Although treatment for children with high-risk metastatic neuroblastoma has improved significantly in the past 20 years, only 45% of these patients become long-term, disease-free survivors, and bone marrow is a frequent site of resistant or recurrent disease. Improvement in survival necessitates development of effective new therapies that target biologically risk-stratified subgroups of patients and also development of effective biomarker assays that assess response and provide surrogates for long-term treatment benefit. Specific Aims: 1) Determine if quantifying "tumor load" in bone marrow and blood with a TaqMan(R) Low Density Array (TLDA) assay for 5 neuroblastoma associated genes improves response evaluation and prediction of outcome compared to immunocytology and clinical evaluations. 2) Determine if bone marrow and blood "microenvironment" gene expression signatures predict outcome and if combining these with tumor load data further improves prediction of outcome. 3) Determine if combining data from the TLDA tumor load/microenvironment assay for blood and marrow and a TLDA predictive gene expression assay for primary tumor from the same patient improves prediction of outcome compared to either assay alone. Research Design and Methods: We developed a new TLDA assay that can simultaneously quantify expression of five neuroblastoma genes ("tumor load") and 38 "microenvironment" genes representing normal blood and marrow cells. This assay quantifies expression of CHGA, DCX, DDC, PHOX2B, and TH so that one tumor cell among 106 normal bone marrow or blood mononuclear cells can be identified. Preliminary studies indicate that "tumor load" in PBSC and bone marrow that does not have detectible tumor cells by immunocytology correlates with outcome. In a separately funded project, we have developed another TLDA assay that quantifies a prognostic 14-gene expression signature in primary MYCN non-amplified tumors to predict outcome, and another signature is being developed for MYCN amplified tumors. We shall extend and validate our preliminary studies by testing 3,000 viably cryopreserved specimens (all have been tested by immunocytology) from three independent cohorts of patients who have been/are being enrolled in six different studies of the Children's Oncology Group. Analysis will take into account when the specimen was obtained (diagnosis and during and at the conclusion of therapy) and treatment (induction, consolidation, and post-consolidation therapies) in evaluating response and predicting outcome compared to immunocytology and standard clinical assessments. Tumor load and microenvironment data for blood and marrow will be combined with gene expression signature data for primary tumors to determine their relationship and their ability to improve prediction of outcome for clinical decision making. Summary: It is anticipated that our new TLDA assay for neuroblastoma cells in marrow and blood will improve prediction of outcome and hence to development of more effective therapy for patients with high-risk metastatic neuroblastoma. PUBLIC HEALTH RELEVANCE: Project Narrative Although treatment has steadily improved in the past 20 years for children with high-risk metastatic neuroblastoma (stage 4), only 45% of these patients survive long-term, and bone marrow is a frequent site of resistant or recurrent disease. We have developed a robust biomarker assay that simultaneously quantifies "tumor load" by expression of tumor cell genes and "microenvironment" by expression of normal marrow and blood cell genes. We anticipate that this assay will become an integral biomarker tool for evaluating response to new therapeutic strategies and for predicting outcome of children with high-risk neuroblastoma.