采用微计算机断层扫描对肿瘤发展的评估和后续反应来治疗肺癌的小鼠模型
Summary
We describe a method for the detection of tumor nodule development in the lungs of an adenocarcinoma mouse model using micro-computed tomography and its use for monitoring changes in nodule size over time and in response to treatment. The accuracy of the assessment was confirmed with end-point histological quantification.
Abstract
Lung cancer is the most lethal cancer in the world. Intensive research is ongoing worldwide to identify new therapies for lung cancer. Several mouse models of lung cancer are being used to study the mechanism of cancer development and to experiment with various therapeutic strategies. However, the absence of a real-time technique to identify the development of tumor nodules in mice lungs and to monitor the changes in their size in response to various experimental and therapeutic interventions hampers the ability to obtain an accurate description of the course of the disease and its timely response to treatments. In this study, a method using a micro-computed tomography (CT) scanner for the detection of the development of lung tumors in a mouse model of lung adenocarcinoma is described. Next, we show that monthly follow-up with micro-CT can identify dynamic changes in the lung tumor, such as the appearance of additional nodules, increase in the size of previously detected nodules, and decrease in the size or complete resolution of nodules in response to treatment. Finally, the accuracy of this real-time assessment method was confirmed with end-point histological quantification. This technique paves the way for planning and conducting more complex experiments on lung cancer animal models, and it enables us to better understand the mechanisms of carcinogenesis and the effects of different treatment modalities while saving time and resources.
Introduction
肺癌是癌症死亡的世界1的周围的首要原因。研究预防，早期发现和肺癌的治疗是在世界各地的许多2,3研究中心正在进行。几种动物模型为肺癌已经开发，并且它们已被证明在研究肺致癌作用和来源的细胞的机制，在确定癌干细胞的存在是有用的，并且在研究各种新的治疗策略4。早期型号小鼠5的敏感菌株依靠致癌物诱发肿瘤发生。敲除和转基因小鼠模型，其中肺癌产生所具体操纵遗传病变的结果的发展已经大大提高了我们对控制肿瘤诱导和模拟几种人类肺癌4的各方面的能力。然而，在使用肺癌动物模型的一个主要挑战是在不存在实时的方法来准确地识别和监测肿瘤的小鼠肺的发生和发展，并记录下它们的大小，以后的任何改变，如它们在治疗反应持续增长或减少。这就迫使研究诉诸几个时间，精力和资源消耗的技术，以确定肿瘤，并评价它们的实验结果。固有小鼠间变化的响应于肿瘤诱导的存在需要在每个实验组使用大量动物的减少数据的变异性。无法评估实时的肿瘤生长或对治疗的反应，迫使研究者盲目安乐死在延长的实验方案的多个时间点的小鼠，以保证它们将收集的正确的数据，造成资源的从样品中的废物在该要么过早或过晚的时间点收集。
在目前的研究中，一种方法利用小动物微-Computed断层（微CT）扫描仪来检测和后续肺肿瘤活小鼠被引入。我们用我们最近描述SFTPC-rtTA和TRE-Fgf9基因-IRES-EGFP双转基因（DT）小鼠迅速发展肺腺癌诱导后用强力霉素6,7。使用显微CT的，使我们能够（除其他外）排除与异常肺部异常小鼠诱导前，确认在肺肿瘤结节的发展诱导后，并且响应于试验性治疗观察肿瘤结节的变化。小鼠和组织学评估的终点安乐死证实显微CT进行的实时评估的准确性。我们相信，这一技术铺平了道路实施使用肺癌动物模型，同时节省了宝贵的资源，缩短观察时间，提高结果的准确性和了解规划更好的实验。
Protocol
Representative Results
Discussion
此处描述了用于肺部异常的实时识别和监测肿瘤结节的发展和在肺癌动物模型中对治疗的反应将使谁正在进行肺癌相关实验计划更多的科学家的基于显微CT-方法准确，高效的实验，同时节省时间和资源。我们以前使用的MRI为同一目的6。扫描和阈值检测肺结节的MRI的清晰度均低于那些在这项研究中6中所述的微型CT扫描。
即使用了类似的肺腺癌小鼠模型（具有不…
Offenlegungen
The authors have nothing to disclose.
Acknowledgements
这项工作是由格兰特 – 在援助从日本学术振兴会KAKENHI为AEH（批准号25461196）和TB（授权号码23390218和15H04833）和国家卫生研究院资助HL111190的（DMO）的支持。作者要感谢山本美雪为她与动物基因分型和组织切片的准备帮助努力。我们感谢合作研究资源，医学院，庆应义塾大学为技术依托和试剂。
Materials
| micro-X-ray–computed tomography | Rigaku | R_mCT2 | |
| NanoZoomer RS Digital Pathology System | Hamamatsu | RS C10730 | |
| NDP.view2 Viewing software | Hamamatsu | U12388-01 | http://www.hamamatsu.com/jp/en/U12388-01.html |
| Isoflurane Vaporizer – Funnel-Fill | VETEQUIP | 911103 | |
| Induction chamber, 2 Liter W9.5×D23×H9.5 | VETEQUIP | 941444 | |
| Isoflurane | Mylan | ES2303-01 | |
| AZD 4547 | LC Labratories | A-1088 | |
| Pentobarbital | Kyoritsu | SOM02-YA1312 | |
| G24 cannula | Terumo | SP-FS2419 | |
| Paraformaldehyde | Wako | 163-20145 | |
| Microtome | Leica | RM2265 | |
| Doxycycline | SLC Japan/PMI Nutrition International | 5TP7 | |
| ImageJ software | National Institute of health | http://imagej.nih.gov/ij/ | |
| Puralube vet ointment (Occular lubricant) | Dechra | NDC 17033-211-38 |
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