Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi Mumbai, India.
J Biosci. 2011 Aug;36(3):499-504. doi: 10.1007/s12038-011-9079-0.
The enormous advances in our understanding of the progression of diseases at the molecular level have been supplemented by the new field of 'molecular imaging', which provides for in vivo visualization of molecular events at the cellular level in living organisms. Molecular imaging is a noninvasive assessment of gene and protein function, protein-protein interaction and or signal transduction pathways in animal models of human disease and in patients to provide insights into molecular pathogenesis. Five major imaging techniques are currently available to assess the structural and functional alterations in vivo in small animals. These are (i) optical bioluminescence and fluorescence imaging techniques, (ii) radionuclide-based positron emission tomography (PET) and single photon emitted computed tomography (SPECT), (iii) X-ray-based computed tomography (CT), (iv) magnetic resonance imaging (MRI) and (v) ultrasound imaging (US). Functional molecular imaging requires an imaging probe that is specific for a given molecular event. In preclinical imaging, involving small animal models, the imaging probe could be an element of a direct ('direct imaging') or an indirect ('indirect imaging') event. Reporter genes are essential for indirect imaging and provide a general integrated platform for many different applications. Applications of multimodality imaging using combinations of bioluminescent, fluorescent and PET reporter genes in unified fusion vectors developed by us for recording events from single live cells to whole animals with high sensitivity and accurate quantification are discussed. Such approaches have immense potential to track progression of metastasis, immune cell trafficking, stem cell therapy, transgenic animals and even molecular interactions in living subjects.
在分子水平上对疾病进展的认识取得了巨大进展，而“分子成像”这一新领域则为活生物体的细胞水平上的分子事件提供了体内可视化。分子成像是对基因和蛋白质功能、蛋白质-蛋白质相互作用和或信号转导途径的非侵入性评估，适用于人类疾病的动物模型和患者，以深入了解分子发病机制。目前有五种主要的成像技术可用于评估小动物体内的结构和功能变化。这些技术是(i)光学生物发光和荧光成像技术，(ii)基于放射性核素的正电子发射断层扫描（PET）和单光子发射计算机断层扫描（SPECT），(iii)基于 X 射线的计算机断层扫描（CT），(iv)磁共振成像（MRI）和(v)超声成像（US）。功能分子成像需要一种针对特定分子事件的成像探针。在涉及小动物模型的临床前成像中，成像探针可以是直接（“直接成像”）或间接（“间接成像”）事件的一个元素。报告基因对于间接成像至关重要，为许多不同的应用提供了通用的综合平台。我们使用融合载体统一记录从单个活细胞到整个动物的事件，讨论了使用生物发光、荧光和 PET 报告基因的多种模态成像的应用，该融合载体具有高灵敏度和准确的定量。这些方法具有巨大的潜力，可以跟踪转移的进展、免疫细胞的迁移、干细胞治疗、转基因动物，甚至是活体分子相互作用。
