质谱分析电刀烟雾中DPPC快速区分肺癌组织的应用及基础研究

Dipalmitoyl phosphatidyl choline (DPPC) is the most important ingredients of Pulmonary Surfactant (PS), and PS was secreted by alveolar type 2 (AT2) cells. It was proved that canceration of AT2 cells were caused by gene mutations, but the relationship between PS metabolism and AT2 cell canceration is unclear; The analysis of protein, nucleic acid and cell morphology were used in clinical commonly, the shortcomings of them is waste time of complex pretreatment. We found Tissue Spray ionization Mass Spectrometry(TSi-MS) can distinguish human lung cancer from noncancerous tissue by the differences of DPPC and other phospholipids, there was rich phospholipids MS signal in electrotome smoke. According to our results, we put forward that the metabolic disorder of PS may be one of the reason which made AT2 cells canceration, Mass Spectrometry detect DPPC in electrotome smoke may be a good idear for lung cancer rapidly diagnosis. To make clear the theoretical of MS detect DPPC in electrotome smoke can distinguish lung cancer, the mechanism of PS metabolic disorder and AT2 cells canceration will be studied by analyze metabolism of DPPC with different tumor-burdened status in mouse and human. Intelligent Electrotome Technology,rised by lung cancer diagnosis with MS detect DPPC in electrotome smoke,may provide a new strategy to malignancy diagnosis based on phospholipids.

二棕榈酰磷脂酰胆碱(DPPC)是肺表面活性物质(PS)的主要活性成份，肺泡2型(AT2)细胞的生理功能是分泌PS，研究发现AT2细胞基因突变可致肺癌，但PS代谢与AT2细胞癌变的联系尚不清楚；临床使用的蛋白、核酸分析和细胞形态学观察等肿瘤诊断技术，存在样本预处理复杂、检测周期长等不足。我们发现(1)组织喷雾电离质谱能根据肺癌及癌旁组织中DPPC等磷脂含量差异区分两种样本，(2)质谱分析电刀烟雾可检出丰富的磷脂类信号。据此提出PS代谢异常与AT2细胞突变致癌机制相关，以及质谱分析电刀烟雾中DPPC能快速区分肺癌组织的假设。本研究拟分析不同荷瘤状态下机体DPPC等磷脂的代谢规律、研究PS代谢异常与肺癌发生的相关机制，为质谱分析电刀烟雾区分肺癌组织提供理论依据；并开发质谱分析电刀烟雾中DPPC快速区分肺癌的智能电刀技术，为基于磷脂快速诊断恶性肿瘤提供新方法。

本研究用电喷雾萃取电离质谱(EESI-MS)技术分析不同荷瘤状态下机体内肺表面活性物质(PS)主要成分DPPC等磷脂代谢的变化，为研究肺表面活性物质(PS)在肺癌发病机制中的作用探索了新思路。目前临床常用的最快的肿瘤诊断方法——术中冰冻病理检查仍存在30分钟左右的时间差，不能完全满足临床要求。细胞膜是细胞最外层的结构、应当最先被观察并用于肿瘤诊断，但由于细胞膜的主要成分磷脂类性质不稳定，染色、分离、纯化等技术不成熟，使得针对脂类的肿瘤诊断方法发展相对滞后。本课题组发现组织喷雾电离质谱(TSi-MS)耦合线性辨别分析(LDA)方法，能够根据DPPC等磷脂的含量差异快速辨别肺癌和癌旁组织样本。质谱分析电刀烟雾检出大量脂类信号。根据手术中高频电刀处理生物组织相当于热致电离的特点，本研究在肺癌手术标本电刀烟雾分析结果：组织电刀处理过程中产生的烟雾中经MS分析，得到了大量的信号，其中主要差异性离子峰为：m/z172.07, m/z734.04, m/z786.11等，经标准品CID鉴定和统计分析，这些差异性代谢物在区别癌组织和癌旁组织烟雾时AUC均在95%左右，敏感性和特异性均达到95%以上。应用PLS-DA分析并对比了这些差异性物质在两组组织电刀烟雾中的含量差异两组样本能明显区分。