犬实验性胃黏膜癌变过程的拉曼指纹谱特征及其发生机制研究

Gastroscopy combined with pathological biopsy is an important means of early diagnosis of gastric cancer, but endoscopic real-time early diagnosis for the cancer is very difficult. The results of spectroscopic studies have shown that there are specific spectral changes in cancer tissue and they are closely related to the changes of their cellular molecular composition and structure .Through our previous studies, we found that there are specificity and regularity of changes on DNA Raman spectroscopy in intestinal metaplasia of gastric mucosa and cancerous tissue, and have design, prepared the fiber probe of the Raman spectrum for real-time detection by gastroscopy successfully. It will become true that real-time detection to stomach lesions by combine with endoscopy and Raman spectroscopy by using the fiber-optic probe. Our study will simulate the development process of gastric carcinogenesis cancer through the canine model. Detecting the Raman spectroscopy of the mucosal tissue at all stages of the process of gastric carcinogenesis(normal, intestinal metaplasia, dysplasia and cancer), by detection of pathological tissue in vitro and detecting the Raman spectroscopy of the gastric lesions in vivo through optical fiber probe. Establish the diagnostic Raman fingerprint, analysis their key information of biological components, and explicit the mechanism of gastric cancer through Raman fingerprint changes. It will be the foundation to diagnose the early gastric cancer real-time, rapidly, noninvasively, using Raman spectroscopy.

胃镜检查加病理活检是胃癌早期诊断的重要手段，但内镜下实时早期诊断非常困难。光谱研究显示癌组织有特异性的光谱变化，这些变化与其细胞分子成分及结构变化密切相关。我们前期研究显示胃黏膜肠化及癌变组织DNA的拉曼光谱检测有特异性及规律性的变化，并已成功设计、制备了用于胃镜下实时检测的拉曼光谱光纤探针。运用光纤探针可将胃镜和拉曼光谱结合对胃内病灶进行实时检测。本课题通过犬胃黏膜癌变模型模拟癌变的发生发展过程，采用体外病理活检、体内光纤探针方法对胃黏膜癌变过程的各个阶段黏膜组织（正常、肠上皮化生、不典型增生及癌变）进行拉曼光谱检测，建立具有诊断价值的拉曼指纹谱，并分析其关键的生物组分信息，明确拉曼指纹谱变化的发生机制，为拉曼光谱分析技术运用到胃癌的早期、实时、快速、无创诊断奠定基础。

摘要：研究背景：胃癌的早期诊断是提高其生存率的关键，但目前胃癌内镜下实时早期诊断十分困难。胃粘膜组织细胞癌变源于其内部物质分子的异常，而这些生化分子的改变可以使其拉曼光谱显示出特征性和规律性的变化。拉曼光谱是一种具有高度分子特异性的指纹光谱技术，癌组织的谱线明显不同于正常组织。研究内容：1）对正常和胃癌基因组DNA、细胞核、细胞、组织进行拉曼光谱测定，光谱解析其表征的物质分子的构型构象、相对含量、所处环境等异常，探究癌变相关生化分子机制。2）对正常和癌变各阶段胃粘膜组织分别进行拉曼光谱测定，确定胃癌的拉曼光谱特征。3）大样本的光谱数据的统计分析，综合比较评价，建立拉曼光谱诊断胃癌的高敏模型及标准。4）内窥镜-光纤探头-拉曼光谱仪有机融合，构建内镜下拉曼光谱实时诊断胃癌的平台。主要结果：1）正常和癌变胃粘膜组织的拉曼光谱特征峰峰形、峰数、峰位、相对峰强存在明显差别，表明DNA、不饱和脂肪酸、色氨酸、组蛋白等分子物质的构型构象及所处环境等发生改变。2）采集75个（正常38、胃癌37）不同个体胃粘膜组织的拉曼光谱（共计235），构建了胃癌的拉曼光谱指纹库。并对胃正常、慢性炎、萎缩肠化、异型增生粘膜组织进行了初步的拉曼光谱测定分析。3）拉曼光谱可以准确诊断胃癌，多元统计学分析构建了高敏诊断模型，诊断正常和癌变胃粘膜组织的灵敏度、特异度及准确率分别为94.59%、86.84%、90.67%。4）初步搭建了集内窥镜-光纤探头-拉曼光谱仪一体的胃癌内镜下实时诊断平台，获得了优良的拉曼图谱。主要结论:胃癌组织的拉曼光谱谱峰变化蕴含着丰富的生化分子信息，拉曼指纹光谱可以准确诊断胃癌。拉曼光谱有望成为实时、快速、无创、高敏的早期诊断胃癌的新技术。