肿瘤生长初期基质层生理特性的活体多光子显微成像研究

Achieving more knowledge about the morphological and physiological characteristics of stroma in precancer will certainly increase our understanding of the mechanism of cancer progression and, as a result, improve the outcome of therapy. However, due to the limitation of technique, few microscopy studies have been carried out to investigate the dynamic changes of stroma in vivo. The mechanism of tumor-induced changes on both collagen fiber and stromal cells in the stroma is unclear. This proposal provides a new strategy to study the dynamic changes of morphological and physiological characteristics of the stroma in precancer development in vivo. An animal tumor model based on the technique of dorsal skinfold chamber in nude mouse will be used as the experiment sample and a home-made high-performance multiphoton microscopy system will be employed to measure both second harmonic generation (SHG) and two-photon excitation autofluorescence signals from the stroma. The time-lapse nonlinear optical images from the same target during cancer progression will be taken and then analyzed with quantitative digital image process methods. Meanwhile, other intrinsic optical signals such as the fluorescence spectra and the SHG anisotropy will also be studied. The purpose of this study is to explore the relationship between the intrinsic optical signals with the different stages of precancer. The results of this project will provide basic scientific knowledge for diagnosis of cancer in future clinical application.

了解肿瘤发展早期基底组织的生理特性对癌症的诊断和治疗具有非常重要的意义。但是由于受到探测技术的限制，对基底组织的活体显微成像研究始终不足。基底组织内胶原纤维（collagen）和基质层细胞（stromal cell）的生理特性随肿瘤发展的变化机制至今还不是很清楚。为此，本项目拟从（1）开发高稳定、高分辨、高重复、多光子显微成像技术；（2）创建合适的裸鼠背部皮窗肿瘤模型；（3）探索高效的数字显微图像特征信息提取方法三个方面入手，活体、原位、动态地研究基底组织内胶原纤维和基质层细胞在早期肿瘤发展过程中的形态、位置、数量等特性随时间的变化情况，从而揭示肿瘤基质层生物自发光学信号（包括自发荧光和二次谐波的图像、光谱信号）与肿瘤发展各阶段之间的关联特性，为进一步实现癌症的早期临床光学诊断提供科学研究基础.

恶性肿瘤是当今人类的头号杀手也是科研人员久攻不克的重大难题。本项目从研究早期肿瘤基底组织的生理特性着手，利用新型光学显微成像方法，探测内源性光学信号并结合数字图像处理技术，试图探索出一条研究肿瘤的新途径。为此，本项目设立了研发成像系统、创建肿瘤模型、提取特性信息三块研究内容。经过三年多不懈的努力，本项目顺利完成以上各项内容,成果包括：（1）研发多套具有独特功能且性能稳定的双光子显微成像系统，其中一套光声与双光子结合的多模态显微成像系统属于世界首创；（2）完成了适用于光学显微成像的小鼠背部皮窗肿瘤模型开发工作；（3）我们发现并总结了肿瘤基质层胶原纤维和基质层细胞随肿瘤发展的变化情况，发现肿瘤周围毛细血管与正常组织毛细血管存在显著差异；（4）我们首次发现，来源于弹性纤维的自体荧光信号可以在体区分小鼠动静脉，并进一步研究了该信号的生物物理基础。通过本项目的实施，培养实习硕士生4人，发表SCI论文3篇，国际会议论文2篇，另有2篇期刊论文尚在撰写中，申请专利5项（其中已获授权4项），参加国际学术会议2人次、国内学术会议4人次。