Construction of gene expression signatures with RAGE

在美国，每8名女性中就有1人患有乳腺癌。目前的治疗方案倾向于将术后辅助化疗扩展到淋巴结阴性且原始肿瘤越来越小的患者，尽管大多数患者似乎并没有从这种治疗中获益。分子特征的建立定义了这些具有不同肿瘤复发可能性的患者的亚组，这将有助于根据患者的预后量身定制治疗。我们还将采用一种称为RAGE的新型全球基因表达分析程序来建立早期淋巴结阴性乳腺肿瘤的基因表达谱。1期将对T1N0M0和T2N0M0乳腺肿瘤进行回顾性研究，其中5年内复发的20例，未复发的20例。RAGE方法将适用于高通量分离和分析技术，多次毛细管电泳，并且通过各种手段将通量增加到每周约10,000次测量。将在40个回顾性肿瘤中分别测量一组约3000个基因的表达水平。这些数据将与项目1中使用SAGE对这些肿瘤子集收集的类似数据相结合。在I期获得的RAGE和SAGE联合数据将用于鉴定一组大约700个候选特征基因，这些基因在复发性和非复发性肿瘤之间的表达存在显著差异，或者预计在乳腺肿瘤发生中起重要作用。然后，RAGE技术将用于II期研究这些候选基因在250例T1N0M0和T2N0M0乳腺肿瘤中的表达。随着SAGE进一步研究（项目1）确定新的候选基因，以及我们对乳腺癌生物学的理解取得进展，其他基因将被添加到这组基因中。最终，我们期望在未来的肿瘤组中确定约1000个基因的表达水平。其表达可能有助于分子特征的新基因将被鉴定和克隆。本项目人员将与项目3和数据管理核心的统计学家、信息科学家和程序员密切合作，分析该数据集，以获得肿瘤群体亚群的分子特征特征。

Breast cancer affects one in eight women in the United States. Current treatment regimes tend to extend post-surgical adjuvant chemotherapy to lymph node negative patients with ever smaller original tumors, even though the majority of such patients do not appear to benefit from such treatment. The establishment of molecular signatures that define subgroups of these patients with different likelihoods of tumor recurrence would be useful allowing therapy to be tailored of the prognosis of the patient. We will also a novel global gene expression analysis procedure called RAGE to establish gene expression profiles for early node- negative breast tumors. A retrospective group of T1N0M0 and T2N0M0 breast tumors, 20 that have recurred within 5 years and 20 that have not, will be studied in Phase 1. The RAGE method will be adapted to a high throughput separation and analysis technology, multiple capillary electrophoresis, and throughput will be increased through various means to about 10,000 measurements per week. Expression levels of a set of approximately 3000 genes will be measured in each of the 40 retrospective tumors. These data will be combined with analogous data collected in Project 1 using SAGE on a subset of these tumors. The combined RAGE and SAGE data obtained in Phase I will be used to identify a set of approximately 700 candidate signature genes that show significant variance in expression between recurrent and non-recurrent tumors or that are expected to be important in breast tumorigenesis. The RAGE technique will then be used in Phase II to study expression of these candidate genes in a prospective set of 250 T1N0M0 and T2N0M0 breast tumors. Additional genes will be added to this set as new candidate genes are identified by further SAGE studies (Project 1) and as advances in our understanding of the biology of breast cancer are made. Ultimately, we expect to determine expression levels for about 1000 genes in the prospective tumor set. Novel genes whose expression may contribute to molecular signatures will be identified and cloned. Personnel in this Project will work closely with statisticians, information scientists and programmers in Project 3 and in the Data Management Core to analyze this dataset for molecular signatures characteristic of subsets of the tumor population.