Development of a Metastatic Breast Cancer model in the nude rat for MRI Cell Tra

MRI Cell Tra 裸鼠转移性乳腺癌模型的建立

• 批准号: 8565389
• 负责人: Joseph Frank
• 金额: --
• 依托单位: CLINICAL CENTER
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8565389
• 关键词: Angiogenesis Inhibitors; Animals; Bioluminescence; Blood; Blood - brain barrier anatomy; Blood Vessels; Brain; Brain Neoplasms; Breast Cancer Cell; Breast Cancer Model; Cell Line; Cells; Cellularity; Characteristics; Clinical; Complementary DNA; Dendrites; Detection; Development; Diagnosis; Diffusion; Diffusion weighted imaging; Disease; Disseminated Malignant Neoplasm; Dose; Edema; Firefly Luciferases; Goals; Human; Image; Imaging Techniques; Infusion procedures; Injection of therapeutic agent; Injury; Label; Lesion; Luciferases; Magnetic Resonance Imaging; Malignant Neoplasms; Maps; Measures; Metastatic Neoplasm to the Bone; Metastatic malignant neoplasm to brain; Micrometastasis; Modeling; Monitor; Multimodal Imaging; Natural History; Neoplasm Metastasis; Neurons; Nude Rats; Optics; Oxygen; Pathology; Perfusion; Permeability; Pharmaceutical Preparations; Photons; Physiologic pulse; Physiological; Prussian blue; Rattus; Relaxation; Rodent; Rodent Model; Site; Solid; Solid Neoplasm; Spinal Cord; Techniques; Time; Tissues; Tumor Oxygenation; Vascular Permeabilities; Weight; Work; blood perfusion; bone; chemotherapeutic agent; clinically relevant; disease natural history; ferumoxides; gene therapy; improved; in vivo; iron oxide; malignant breast neoplasm; meetings; nanoparticle; neoplastic cell; pre-clinical; prognostic; response; stem cells; success; treatment response; tumor; tumor growth

The purpose of this study was to develop a metastatic brain tumor model of breast cancer in the rat to monitor the natural history of the disease using a multimodal imaging approach with magnetic resonance imaging (MRI) scanner and in vivo bioluminescence imaging (BLI). MDA-MB231BR cell line is a brain seeking metastatic breast cancer line that was stably transfected to express the firefly luciferase cDNA (LUC) and was magnetically labeled with superparamagnetic iron oxide nanoparticles (SPION) ex vivo for early monitoring by MRI. Nude rats underwent intracardiac infusion SPION ferumoxides labeled MDAMB231BRLUC (231BRL) cells. FEPro labeled 231BRL cells injected rats developed multiple brain and spinal cord metastasis and all rats with brain lesion had multiple skeletal metastasis. Prussian blue positive breast cancer cells could be detected in animals up to 1 week following intracardiac injection of SPION labeled cells. BLI demonstrated increase in luciferase photon flux activity in the brain and bones of the rats while MRI revealed numerous hypointense regions corresponding to SPION labeled cells in the brain within the first 3 days following injection of cell. Quantifying the number of labeled stem cells in target tissues is of great importance to optimize dose and timing of cellular therapy. We has employed a multi-gradient echo pulse sequence to calculate T2* relaxation times to improve the detection of labeled cells within the voxel. We also have investigated the use of Blood oxygen level dependant (BOLD) MRI has been used to evaluate metastatic tumor oxygenation and perfusion. It is unknown whether BOLD can be used for diagnosis in addition to its prognostic potential. Day 1 post injection of FEPro breast cancer cells, numerous hypointense regions were detected on T2*w images throughout rat brain consistent with clusters of tumor cells in the vasculature. At day 36 post injection of cells a total of 34 cortical tumors were identified on the T2-weighted ex vivo MR images. These regions were mapped to the in vivo images. Of these tumors, 26 had noticeable BOLD decreases in the corresponding region from the week prior (day 29) MRI, and 17 had BOLD decreases 2 weeks prior (day 22) MRI. Importantly, the BOLD effects could be detected when the tumor was less than 500 m. BOLD MRI was an early marker of metastatic tumor development, and the changes are consistent with vascular abnormalities from undiagnosed micrometastasis disease. Despite the difficulties in attributing BOLD changes to oxygenation or perfusion, BOLD MRI may aid the detection of developing metastases. Pharmacological approaches to treat breast cancer metastases in the brain have been met with limited success. In part, the impermeability of the blood brain barrier (BBB) has hindered delivery of chemotherapeutic agents to metastatic tumors in the brain. BBB-permeable chemotherapeutic drugs are being developed, and noninvasively assessing the efficacy of these agents will be important in both preclinical and clinical settings. We used dynamic contrast enhanced (DCE) and diffusion weighted imaging (DWI) are magnetic resonance imaging (MRI) techniques to monitor metastatic breast cancer in the rat brain, tumor vascular permeability and cellularity. We demonstrate that brain and bone metastases in the MB 231BR model develop with distinct physiological characteristics as measured with MRI. Brain metastases had limited permeability of the BBB as assessed with DCE and an increased apparent diffusion coefficient (ADC) measured with DWI compared to the surrounding brain. Microscopically, we showed that brain metastases were highly infiltrative, grew through vessel co-option, and caused extensive edema and injury to the surrounding neurons and their dendrites. By comparison, metastases situated in the leptomenengies or in the bone were demonstrated to have high vascular permeability and significantly lower ADC values suggestive of hypercellularity. On histological examination, tumors in the bone and leptomenengies were solid masses with distinct tumor margins. The different characteristics of these tissue sites highlighted the influence of the microenvironment on metastatic tumor growth. The implication of this work raises the issue of the suitability of DWI and DCE to evaluate the response of chemotherapeutic and anti-angiogenic agents used to treat co-opted brain metastases in contrast to these techniques being used in solid tumor masses

这项研究的目的是开发大鼠乳腺癌的转移性脑肿瘤模型，以使用磁共振成像（MRI）扫描仪和体内生物发光成像（BLI）的多模式成像方法来监测疾病的自然史。 MDA-MB231BR细胞系是一种脑寻求转移性乳腺癌系，稳定转染以表达萤火虫荧光素酶cDNA（LUC），并用超级磁磁铁氧化铁纳米颗粒（SPION）磁性标记为MRI的早期监测。裸大鼠接受了心脏内输注spion perumoxide标记为MDAMB231BRLUC（231BRL）细胞。 FEPRO标记为231BRL细胞注入的大鼠发育于多个脑和脊髓转移，所有患有脑病变的大鼠均具有多个骨骼转移。在心脏内注射SPION标记的细胞后，可以在1周内在动物中检测到普鲁士蓝色阳性乳腺癌细胞。 BLI表明在大脑和大鼠的骨骼中荧光素酶光子通量活性增加，而MRI揭示了在注射细胞后的前3天内与SPION相对应的大脑标记细胞的许多低端区域。量化靶组织中标记的干细胞的数量对于优化细胞治疗的剂量和时间至关重要。 我们已经采用了多速率回声脉冲序列来计算T2*松弛时间，以改善体素内标记的细胞的检测。 我们还研究了血氧水平依赖性（BOLD）MRI的使用已用于评估转移性肿瘤的氧合和灌注。 除了其预后潜力外，是否还可以将BOLD用于诊断，这是未知的。注射FEPRO乳腺癌细胞后第1天，在整个大鼠大脑的T2*W图像上检测到许多与脉管系统中肿瘤细胞簇一致的高压区域。 在注射细胞后第36天，在T2加权的离体MR图像上总共确定了34个皮质肿瘤。 这些区域被映射到体内图像。 在这些肿瘤中，相应区域（第29天）MRI的26个肿瘤在相应区域中有明显的大胆降低，而17个在2周（第22天）MRI前的BOLD降低。重要的是，当肿瘤小于500 m时，可以检测到大胆的效果。 BOLD MRI是转移性肿瘤发育的早期标志物，这些变化与未诊断的微量症疾病的血管异常一致。 尽管将大胆的变化归因于氧合或灌注很困难，但粗体MRI可能有助于检测发展的转移酶。 治疗大脑中乳腺癌转移的药理方法的成功有限。在某种程度上，血液脑屏障（BBB）的不渗透性阻碍了化学治疗剂对大脑转移性肿瘤的递送。正在开发出BBB可渗透的化学治疗药物，在临床前和临床环境中，非侵入性评估这些药物的功效将很重要。我们使用动态对比度增强（DCE）和扩散加权成像（DWI）是磁共振成像（MRI）技术来监测大鼠脑中的转移性乳腺癌，肿瘤血管渗透性和细胞性。我们证明MB 231BR模型中的脑和骨转移具有具有MRI测量的不同生理特征。与周围的大脑相比，用DCE评估的BBB渗透性有限，并且用DWI测量的明显扩散系数（ADC）增加。从显微镜上看，我们表明脑转移具有高度浸润，通过血管合作生长，并对周围神经元及其树突引起了广泛的水肿和损伤。相比之下，位于瘦素或骨骼中的转移酶被证明具有高血管通透性，并且明显较低的ADC值提示了超细胞性。在组织学检查中，骨骼和瘦素中的肿瘤是具有不同肿瘤边缘的固体。这些组织部位的不同特征突出了微环境对转移性肿瘤生长的影响。这项工作的含义提出了DWI和DCE的适用性问题，以评估用于治疗相应脑转移酶的化学治疗和抗血管生成剂的反应，与这些技术相比