MicroRNAs for monitoring tumor progression and predicting response to therapy

描述(申请人提供)：背景：微RNA(MiRs)在乳腺肿瘤中发生改变，影响肿瘤的发生和发展。由于MIR在循环中非常稳定，它们作为乳腺癌的非侵入性生物标志物也具有巨大的潜力。事实上，已经在乳腺癌患者中检测到循环MIR，但将其解释为微创生物标记物的相关性受到不一致结果的限制。此外，循环中miR的细胞来源和调节这些潜在miR生物标志物的分子机制仍不清楚。为了解决这些问题，建立了一个高度相关的动物模型，用于体内潜在的miR生物标志物的研究。带有X连锁肿瘤抑制基因Foxp3(Foxp3sf/+)Scurfy(SF)突变的老年小鼠会患上自发性乳腺癌和肿瘤肺转移。对Foxp3sf/+雌性小鼠循环miRs的分析表明，在肿瘤进展和肺转移过程中，血浆miR-200C/141和miR-155水平显著升高，这些结果在一小部分乳腺癌患者中得到了验证。因此，这些MIR似乎是检测人类乳腺癌进展和预测肿瘤治疗反应的新型生物标志物的理想候选者。假设和目标：中心假设是循环中的miR-200C/141和miR-155是早期发现和预测肿瘤进展和治疗反应的有用生物标志物。这一假设将在三个具体目标中得到验证：1)在大量患者中验证潜在的miR生物标记物；2)确定miR生物标记物在肿瘤进展的早期检测和治疗反应预测中的作用；3)阐明循环miR生物标记物的起源和调节。方法：首先，在Foxp3sf/+小鼠模型中确定的miR生物标志物的上调将使用TaqMan miR试验在大量乳腺癌患者中进行验证。将使用最优的方法、材料、对照和匹配的个体来确保数据的统计学意义 这一验证。其次，我们将确定miR生物标志物是否对早期检测有用 肿瘤进展，尤其是肿瘤转移。将通过与现有生物标记物的比较来评估miR生物标记物在预测乳腺癌患者治疗反应中的作用。第三，我们将使用FOXP3 Tet-off MCF7细胞来确定乳腺癌细胞是否释放miRs并受到FOXP3的调控。Foxp3sf/+小鼠模型将用于进一步研究循环miR生物标志物的细胞来源。创新和意义：这项研究将首次探讨1)miR生物标记物在预测治疗反应中的作用，2)体内肿瘤进展过程中循环miR生物标记物的调节机制。如果得到证实，这些miR生物标记物将为改善FOXP3缺陷乳腺癌的预后和降低死亡率提供非侵入性工具。

DESCRIPTION (provided by applicant): Background: MicroRNAs (miRs) are altered in breast tumors, influencing tumor development and progression. As miRs are remarkably stable in circulation, they also have enormous potential as non-invasive biomarkers for breast cancer. Indeed, circulating miRs have been detected in breast cancer patients, but interpretation of their relevance as minimally invasive biomarkers is limited by inconsistent results. Furthermore, the cellular source of circulating miRs and the molecular mechanisms regulating these potential miR biomarkers remain unclear. To address these issues, a highly relevant animal model for in vivo investigation of potential miR biomarkers was established. Aging mice with a Scurfy (sf) mutation of the X-linked tumor suppressor, Foxp3 (Foxp3sf/+), develop spontaneous breast cancer and tumor lung metastases. Analysis of circulating miRs in Foxp3sf/+ female mice revealed that plasma miR-200c/141 and miR-155 levels increase dramatically during tumor progression and lung metastasis, and these results were validated in a small population of breast cancer patients. Thus, these miRs appear as ideal candidates for novel biomarkers to detect the progression of human breast cancer and predict tumor response to therapies. Hypothesis and Goals: The central hypothesis is that circulating miR-200c/141 and miR-155 are useful biomarkers for early detection and prediction of tumor progression and therapeutic response. This hypothesis will be tested in three specific aims: 1) To validate potential miR biomarkers in a large patient population, 2) To determine the utility of the miR biomarkers in the early detection of tumor progression and prediction of therapeutic response, and 3) To elucidate the genesis and regulation of circulating miR biomarkers. Approach: First, the upregulation of the miR biomarkers identified in the Foxp3sf/+ mouse model will be validated in a large population of breast cancer patients using a TaqMan miR assay. The most optimal methods, materials, controls, and matched individuals will be used to ensure the statistical significance of this validation. Second, we will determine if the miR biomarkers are useful for the early detection of tumor progression, especially tumor metastasis. The utility of miR biomarkers in predicting response to treatments in breast cancer patients will be estimated by comparison with current biomarkers. Third, we will use FOXP3 Tet-off MCF7 cells to determine if miRs are released from breast cancer cells and regulated by FOXP3. The Foxp3sf/+ mouse model will be used to further investigate the cellular sources of circulating miR biomarkers. Innovation and Significance: This study will be the first to investigate 1) the utility of the miR biomarkers in predicting response o therapies, and 2) the mechanisms regulating circulating miR biomarkers during tumor progression in vivo. If confirmed, these miR biomarkers will provide non-invasive tools for improving outcomes and decreasing mortality in breast cancers with FOXP3 defects.