Prognostic Models in Diffuse Large B-Cell Lymphoma

描述（由申请人提供）：弥漫性大B细胞淋巴瘤（DLBCL）的特征是显著的生物学和临床异质性。在CHOP时代，已经证明DLBCL患者的生存可以通过测量有限数量的基因的表达来预测。然而，标准治疗已经发展到包括利妥昔单抗与CHOP。初步研究表明，添加利妥昔单抗改变了特定分子生物标志物的预测能力，并且与利妥昔单抗的抗肿瘤作用相关的新生物标志物可能变得具有临床意义。因此，迫切需要建立可靠的基于生物标志物的DLBCL患者预后模型，这些患者接受目前标准的R-CHOP方案治疗，这可能会改变我们的医学实践方式。此外，所有以前的模型都是基于冷冻标本中的RNA测量，其可用性有限，从而限制了所提出的预后模型的适用性。使用RNA或免疫组织化学分析基因表达的广泛可用的石蜡包埋样品的基础上的预后模型的构建将允许这些模型在日常临床实践中的立即和广泛的适用性。 该项目是基于一种新的方法，从福尔马林固定，石蜡包埋的组织中提取RNA，在我们的实验室开发，它允许可靠的测量基因表达的实时PCR或寡核苷酸微阵列。该方法将用于实现本项目的目标，包括：1。通过基于阵列的基因表达谱鉴定表达与用R-CHOP治疗的DLBCL患者的存活相关的基因列表; 2.基于石蜡标本RNA构建并验证石蜡基实时PCR基因表达预测模型; 3.检查与利妥昔单抗在用R-CHOP治疗的DLBCL患者中的抗肿瘤作用相关的生物标志物的生存预测能力; 4.基于通过免疫组织化学在蛋白质水平上测量的有限组基因的表达，构建用R-CHOP治疗的DLBCL患者的预后模型。 这些研究应该为最常见类型的淋巴瘤定义基于石蜡的分子预后模型，这些模型将用于临床实践，并将增加当前临床预后指数的预后能力。预测模型的常规应用将能够识别标准治疗失败的高风险患者，并可能形成DLBCL风险调整治疗的基础。此外，鉴定包括预测模型的基因-蛋白质将指出DLBCL亚型的不同发病机制，并可能导致识别新的分子治疗靶点。此外，使用新的RNA提取方法建立基于石蜡的RNA预后模型可以作为其他淋巴瘤和肿瘤的范例。

DESCRIPTION (provided by applicant): Diffuse large B-cell lymphoma (DLBCL) is characterized by marked biological and clinical heterogeneity. In the CHOP-era, it was demonstrated that survival of DLBCL patients can be predicted by measurement of expression of a limited number of genes. However, the standard treatment has evolved to include the rituximab with CHOP. Initial studies suggest that addition of rituximab changes the predictive power of specific molecular biomarkers and it is possible that new biomarkers associated with the anti-tumor effects of rituximab may become prognostically significant. Therefore, there is an urgent need to establish reliable biomarker-based prognostic models for DLBCL patients treated with the current standard regimen of R-CHOP, which will potentially change the way we practice medicine. In addition, all the previous models were based on RNA measurement in frozen specimens, which availability is limited thus restricting applicability of the proposed prognostic models. Construction of prognostic models based on widely available paraffin embedded samples using either RNA or immunohistochemistry for analysis of gene expression would allow immediate and widespread applicability of these models in daily clinical practice. This project is based on a new methodology of RNA extraction from formalin-fixed, paraffin-embedded tissues, developed in our laboratory, which allows reliable measurement of gene expression by either real-time PCR or oligo-microarrays. This methodology will be used to accomplish the goals of this project that include: 1. Identify a list of genes which expression correlates with survival of DLBCL patients treated with R-CHOP by array-based gene expression profiling; 2. Construct and validate a paraffin-based real-time PCR gene expression prognostic mode based on RNA derived from paraffin specimens; 3. Examine the survival predictive power of biomarkers associated with the anti-tumor effects of rituximab in DLBCL patients treated with R-CHOP; 4. Construct a prognostic model for DLBCL patients treated with R-CHOP based on the expression of a limited set of genes measured at the protein level by immunohistochemistry. These studies should define paraffin-based molecular prognostic models for most common type of lymphoma that will be used in clinical practice and will add to the prognostic power of the current clinical prognostic indexes. Routine application of the prediction models will enable identification of patients at high risk for standard therapy failure and may form the basis for risk-adjusted therapies for DLBCL. Furthermore, identification of genes-proteins comprising the predictive models will point to distinct pathogenesis mechanisms of DLBCL subtypes and potentially lead to recognition of new molecular therapeutic targets. Further, establishment of a paraffin-based RNA prognostic model using the new methodology of RNA extraction could serve as a paradigm for other lymphomas and tumors.