In Vivo Bioimaging Model to Study Inducible Drug Resistance in Cancer

研究癌症诱导耐药性的体内生物成像模型

• 批准号: 8458907
• 负责人: SUSAN E KANE
• 金额: $ 31.41万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-10-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8458907
• 关键词: ABCB1 gene; Acute; Affect; Animal Model; Animals; Antineoplastic Agents; Biological Models; Breast; Breast Cancer Model; Cancer Patient; Chemicals; Cis-Acting Sequence; Clinical; Development; Drug Kinetics; Drug resistance; Elements; Engineering; Evaluation; Event; Firefly Luciferases; Gene Expression; Genes; Genetic Crosses; Genetic Recombination; Genomics; Health; Human; Image; Imaging technology; In Situ; Intestines; Kidney; Kinetics; Knock-in Mouse; Knowledge; Ligands; Link; Liver; Longitudinal Studies; Malignant Neoplasms; Mammary Gland Parenchyma; Measurement; Measures; Mediating; Messenger RNA; Modeling; Monitor; Multi-Drug Resistance; Mus; Normal tissue morphology; Organ; Outcome; Pharmaceutical Preparations; Pharmacotherapy; Physiological; Regulation; Reporter; Reporter Genes; Research; Resistance; Role; Signal Transduction; Stimulus; System; Technology; Time; Tissues; Trans-Activators; Transcriptional Regulation; Transgenic Model; Translations; Work; Xenobiotics; bioimaging; cancer therapy; chemotherapy; homologous recombination; in vivo; insight; mRNA Stability; malignant breast neoplasm; molecular imaging; novel; novel strategies; overexpression; recombinase; response; tool; tumor; tumor progression; tumorigenesis; uptake

DESCRIPTION (provided by applicant): Transcriptional regulation represents the major mechanism of controlling gene expression, yet we have little direct knowledge of how genes are regulated in the whole body, due largely to an inability to observe and measure changes in gene expression under real physiological conditions and in real time. For similar reasons, it has not been possible to study directly the effects of given cancer therapies on their target(s), if mediated at the transcriptional level. However, the recent revolution in molecular imaging has yielded novel tools for performing noninvasive, in vivo imaging of gene expression. A biologically relevant application of imaging technology is to target, by homologous recombination, a reporter gene into the genomic locus of an endogenous gene so that the regulated expression of that gene can be monitored non-invasively, in real time, and in response to internal and external signals. We have established such a system using the mouse mdr1a locus as a proof of principle and as a biologically important gene. Multidrug resistance (MDR) remains a serious impediment to curative chemotherapy in cancer patients. One mechanism of MDR is the enhanced expression of the MDR1 gene. MDR1 overexpression has been associated with drug resistance in many human cancers, but its contribution to clinical outcomes remains unresolved. Systematic longitudinal studies to determine MDR1's role in resistance are difficult, if not impossible, to perform in humans and an adequate animal model to study such questions has not previously been available. The role of MDR1 in drug pharmacokinetics is well established, but the regulation of MDR1 in normal organs involved in drug uptake and clearance is poorly understood. In our preliminary studies: 1) We have engineered mdr1a+/fLUC mice that have firefly luciferase (fLUC) targeted to the mdr1a gene's genomic locus in a way that makes in-frame expression of fLUC conditional on Cre-mediated recombination. 2) We have shown that expression of fLUC under the control of the endogenous mdr1a gene locus is a faithful in vivo reporter for mdr1a expression in the basal, steady state. 3) We have also demonstrated that fLUC can be used to monitor induction of mdr1a gene expression in response to xenobiotic stimuli. We now propose to use this non-invasive model system to study mdr1a gene expression in the in vivo setting. We will also extend the model to be able to study both the cis-acting and trans-acting factors that control mdr1a gene expression at the transcriptional, post-transcriptional and translational level. Aim 1 is to determine if mdr1a is induced in normal organs in a tissue-specific fashion. Aim 2 is to determine if mdr1a is induced during breast cancer progression and/or treatment. Aim 3 is to determine if specifi trans-acting and cis-acting factors are required for mdr1a induction in specific tissues.

描述（由申请人提供）：转录调节代表了控制基因表达的主要机制，但是我们几乎没有直接了解整个身体的基因如何调节，这在很大程度上是由于无法观察和衡量实际生理条件下和实时的基因表达的变化。出于类似的原因，如果在转录水平上介导，则不可能直接研究给定的癌症疗法对其靶标的影响。然而，最近的分子成像革命产生了用于进行基因表达的无创的体内成像的新工具。成像技术与生物学相关的应用是通过同源重组将记者基因靶向内源基因的基因组基因座，以便可以实时非侵入性地监测该基因的调节表达，并响应内部和外部信号。我们已经使用小鼠MDR1A基因座作为原理和生物学上重要的基因建立了这样的系统。多药耐药性（MDR）仍然是癌症患者治愈化疗的严重障碍。 MDR的一种机制是MDR1基因的增强表达。 MDR1的过表达与许多人类癌症中的耐药性有关，但其对临床结果的贡献仍未解决。确定MDR1在抗药性中的作用的系统纵向研究很难在人类中执行（即使不是不可能），并且以前尚未获得适当的动物模型来研究此类问题。 MDR1在药物药代动力学中的作用已经很好地确定，但是对参与药物摄取和清除率的正常器官中MDR1的调节知之甚少。在我们的初步研究中：1）我们已经设计了针对MDR1A基因基因组基因源的MDR1A+/FLUC小鼠，其方式使CRE介导的重组有条件地表达FLUC的框架表达。 2）我们已经表明，在内源性MDR1A基因基因座的控制下FLUC的表达是在基础稳定状态下MDR1A表达的体内记者的忠实记者。 3）我们还证明，FLUC可用于响应异种生物刺激的响应来监测MDR1A基因表达的诱导。现在，我们建议使用这种非侵入性模型系统来研究体内环境中的MDR1A基因表达。我们还将扩展该模型，以便能够研究在转录，转录后和翻译水平上控制MDR1A基因表达的顺式作用和反式作用因子。 AIM 1是确定以组织特异性方式在正常器官中诱导MDR1A。 AIM 2是确定在乳腺癌进展和/或治疗过程中是否诱导MDR1A。目的3是确定特定组织中MDR1A诱导是否需要特定的反式作用和顺式作用因子。