质谱成像原位探究肿瘤相关代谢物谱

发布时间：2018-05-29 17:19

本文选题：质谱成像 + 脂类　；参考：《北京协和医学院》2015年博士论文

【摘要】：众所周知,癌症是世界范围内造成人口死亡和经济损失的主要原因之一。人们针对这种疾病的研究已经持续多年,但是研究方法还局限于相对传统的技术。近年来,质谱成像(MSI)作为一种快速且原位的分析方法正在飞速发展。该技术可在无标记的情况下同时检测样本表面多种分子的空间分布,为我们进行肿瘤诊断及相应机理研究提供了新的手段。本研究采用基质辅助激光解吸电离(MALDI)傅里叶变换离子回旋共振质谱(FTICR MS)技术,研究肿瘤组织中脂类等多种代谢物的分布,旨在寻找可用于肿瘤诊断的潜在标志物并探究肿瘤微环境中代谢物的变化规律。1.组织成像结合血液分析寻找具有甲状腺癌诊断能力的脂类标志物血液与组织中脂类的变化与肿瘤密切相关。本研究采用MALDI-FTICR MS方法分别对甲状腺癌患者(恶性、良性)的36例组织样本及289例血液样本进行分析,以寻找组织和血液中协同变化的脂类分子。多因素统计结合质谱成像结果发现甲状腺癌(恶性、良性)患者与正常人群的组织和血液样本中有10种脂类分子出现显著差异(卵磷脂3个、磷脂酸6个和鞘磷脂1个)。诊断分析发现卵磷脂(PC)(34:1)、鞘磷脂(SM)(34:1)和磷脂酸(PA)(36:3)的脂类标志物组合对于甲状腺癌恶性、良性患者及正常人群有很好的诊断能力。2.质谱成像原位分析六种癌症组织中脂类代谢物的变化规律乳腺癌、肺癌、结直肠癌、食管癌、胃癌和甲状腺癌等六种癌症在世界范围内具有很高的发病率和死亡率。文献报道脂类从头合成途径的激活是肿瘤发生发展的早期共性事件。本研究使用质谱成像方法结合2,5-二羟基苯甲酸(DHB)和1,8-二氨基萘(DMAN)基质分别在正、负离子模式下大规模分析了来自六种癌症的134例肿瘤组织样本。多因素统计结合质谱成像结果发现单不饱和脂肪酸和磷脂在肿瘤区显著上调,多不饱和的脂肪酸和脂类在相同区域显著下调。免疫组化结果显示脂肪酸合成酶(FASN)、硬脂酰去饱和酶(SCD1)以及胆碱激酶(CKa)在肿瘤区均出现上调。根据以上结果,六种癌症组织中的脂类从头合成途径可能被激活,且该途径在肿瘤区促进单不饱和脂类分子的合成,同时抑制多不饱和脂类的合成。3.电场辅助循环喷雾系统结合高分辨率质谱研究临床组织样本中低分子量代谢物的分布低分子量代谢物(分子量500 Da)作为一种重要的细胞成分与肿瘤的发生发展密切相关。但是,MALDI MSI对于低分子量代谢物在组织表面的检测存在着灵敏度不高和基质峰干扰的问题。本研究采用电场诱导循环喷雾系统(EFASS)在组织表面喷涂基质,结合FTICR MS实现高质量分辨质谱成像。与空气喷枪和真空升华等传统喷基质方法比较时发现EFASS能显著提高质谱检测低分子量代谢物的灵敏度和检测数量。使用该方法分析胃癌组织表面低分子量代谢物的分布,发现单不饱和脂肪酸(棕榈酸、油酸)和单磷酸核苷(单磷酸尿苷、单磷酸腺苷、单磷酸尿苷)在肿瘤区显著上调,核苷(肌苷、鸟苷、尿苷)和唾液酸在相同区域显著下调。
[Abstract]:It is well known that cancer is one of the major causes of population death and economic loss worldwide. Research on this disease has lasted for many years, but the research method is limited to relative traditional technology. In recent years, mass spectrometry (MSI) is developing rapidly as a fast and in-situ analysis method. The simultaneous detection of the spatial distribution of a variety of molecules on the surface of the sample under unmarked conditions provides a new method for our tumor diagnosis and the study of the corresponding mechanisms. This study uses the matrix assisted laser desorption ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to study a variety of metabolites in tumor tissues. The purpose of this study is to search for potential markers for cancer diagnosis and to explore the changes in metabolites in the tumor microenvironment.1. tissue imaging combined with blood analysis to find the lipid markers in the blood and tissue of thyroid cancer. The changes of lipids in the blood and tissues are closely related to the tumor. This study uses the MALDI-FTICR MS method to treat a tumor, respectively. 36 tissue samples and 289 blood samples were analyzed to find the lipid molecules in tissue and blood. The results of multivariate statistical combined mass spectrometry found that the thyroid cancer (malignant, benign) patients had significant differences in 10 kinds of lipid molecules in the tissues and blood samples from the normal population (the malignant, benign). Phosphatidylcholine 3, phosphatidic acid 6 and sphingomyelin 1. Diagnostic analysis found that the lipid markers of PC (34:1), sphingomyelin (SM) (34:1) and phosphatidic acid (PA) (36:3) were good for the diagnosis of malignant thyroid cancer, benign patients and normal people with a good diagnostic energy.2. mass spectrometry in situ analysis of lipid metabolites in six cancer tissues Six cancers, such as breast cancer, lung cancer, colorectal cancer, esophageal cancer, gastric cancer, and thyroid cancer, have high morbidity and mortality worldwide. It is reported that activation of lipids from ab initio pathway is an early common event in the development of tumor. This study combines 2,5- two hydroxybenzoic acid (DHB) and 1,8- two by mass spectrometry A large scale analysis of 134 tumor tissue samples from six cancers was carried out in a positive and negative ion model. The results of multi factor statistical combined mass spectrometry found that monounsaturated fatty acids and phospholipids were significantly up-regulated in the tumor area, and polyunsaturated fatty acids and lipids were significantly down in the same region. The immunohistochemical results showed that the results of DMAN were significantly reduced. The fatty acid synthetase (FASN), stearoyl desaturase (SCD1) and choline kinase (CKa) are up-regulated in the tumor areas. According to the above results, the lipo synthesis pathway in the six cancer tissues may be activated, and this pathway promotes the synthesis of monounsaturated lipid molecules in the tumor area and inhibits the synthesis of.3. electricity from polyunsaturated lipids. The distribution of low molecular weight metabolites (molecular weight 500 Da) in clinical tissue samples is closely related to the occurrence and development of tumor as an important cell component. However, MALDI MSI is sensitive to the detection of low molecular weight metabolites on the tissue surface. This study uses electric field induced circular spray system (EFASS) to spray substrate on tissue surface and combine with FTICR MS to achieve mass resolution mass spectrometry. Compared with the traditional spray matrix method, such as air spray gun and vacuum sublimation, it is found that EFASS can significantly improve the sensitivity of mass spectrometry to detect low molecular weight metabolites. This method was used to analyze the distribution of low molecular weight metabolites on the surface of gastric carcinoma. It was found that monounsaturated fatty acids (palmitic acid, oleic acid) and monophosphate (uridine monophosphate, adenosine monophosphate, uridine monophosphate) were significantly up-regulated in the tumor area, and the nucleoside (myoside, guanosine, uridine) and sialic acid were significantly down down in the same region.
【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R730.4

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