基于UPLC-MS技术的鼻咽癌血浆脂质组学初步研究

发布时间：2018-04-11 19:13

本文选题：鼻咽癌 + 脂质组学　；参考：《北京协和医学院》2015年博士论文

【摘要】：目的：鼻咽癌是来源于鼻咽腔或鼻咽隐窝表面上皮的恶性肿瘤,具有易复发及早期转移的特点。鼻咽癌的预后与临床分期直接相关,但由于鼻咽癌临床表现不特异以及缺乏简单有效的检测手段,使得大多数鼻咽癌患者就诊时疾病已发展到中晚期。研究发现Epstein-Barr病毒可以影响宿主细胞的脂质代谢。Epstein-Barr病毒与鼻咽癌的发生密切相关,鼻咽癌患者作为Epstein-Barr病毒的宿主之一,其脂质代谢也可能受到影响。因此对鼻咽癌患者进行脂质代谢组学研究,将有助于进一步探讨鼻咽癌的发生机制。然而目前尚缺乏针对鼻咽癌的脂质组学的研究。本研究通过分析初诊未治鼻咽癌患者与健康人群的血浆脂质代谢情况,试图寻找可能的诊断标志物以及发现可能存在的代谢途径变化。方法：本研究选取中山大学附属肿瘤医院就诊的10例初诊未治鼻咽癌患者和10例健康志愿者作为研究对象,采用超高效液相色谱-质谱联用技术(Ultra-performance Liquid Chromatography-mass spectrometry, UPLC-MS)检测血浆样本中的脂质类代谢物。结果：通过UPLC-MS检测及XCMS处理分析,在正负离子检测模式下分别发现6914和4004个变量。进一步运用主成分分析对包含鼻咽癌组和健康对照组脂质代谢信息的二维数据阵进行无监督数据分析,样本聚类良好。接着采用偏最小二乘判别分析进行有监督的数据分析,并采用500次置换验证防止模型过度拟合,同时确定主成分数。运用正交偏最小二乘判别分析构建的统计学模型,并结合模型获得的VIP值、jack-knifed置信区间载荷图以及代谢轮廓图筛选差异变量。最后剔除差异变量中的噪音、假峰同位素及碎片离子,最终获得136个差异代谢物,其中29个代谢物能在数据库中检索到分子式。本研究对比分析初诊未治的鼻咽癌组和健康对照组的脂质组学结果,发现属于脂肪酸类、甘油酯类、甘油磷脂类和鞘糖脂类的代谢物分子在鼻咽癌患者中含量明显高于健康对照组,而属于鞘磷脂类的神经酰胺在鼻咽癌组中含量低于健康对照组。结论：本研究发现了一系列可作为鼻咽癌潜在诊断标志物的脂类小分子代谢物并阐述了差异代谢物的生物学意义。通过对鼻咽癌患者中可能发生变化的脂质代谢途径进行讨论,对鼻咽癌的发生机制有了进一步了解。
[Abstract]:Objective: nasopharyngeal carcinoma (NPC) is a malignant tumor originating from nasopharyngeal cavity or nasopharyngeal recess.The prognosis of nasopharyngeal carcinoma is directly related to the clinical stage. However, because of the nonspecific clinical manifestations of nasopharyngeal carcinoma and the lack of simple and effective means of detection, most patients with nasopharyngeal carcinoma have developed to the middle and late stage of the disease.It was found that Epstein-Barr virus can affect lipid metabolism of host cells. Epstein-Barr virus is closely related to the occurrence of nasopharyngeal carcinoma. As one of the hosts of Epstein-Barr virus, the lipid metabolism of NPC patients may also be affected.Therefore, the study of lipid metabolism in patients with nasopharyngeal carcinoma will be helpful to further study the pathogenesis of nasopharyngeal carcinoma.However, there is still a lack of lipid studies for nasopharyngeal carcinoma.In this study, we analyzed the plasma lipid metabolism in untreated nasopharyngeal carcinoma patients and healthy people, and tried to find out the possible diagnostic markers and possible metabolic pathway changes.Methods: ten newly diagnosed patients with untreated nasopharyngeal carcinoma and 10 healthy volunteers from Cancer Hospital affiliated to Sun Yat-sen University were selected as subjects.Ultra-performance Liquid Chromatography-mass spectroscopy (UPLC-MS) was used to detect lipid metabolites in plasma samples.Results: 6914 and 4004 variables were found in positive and negative ion detection mode by UPLC-MS detection and XCMS analysis.Furthermore, the unsupervised data matrix containing lipid metabolism information in nasopharyngeal carcinoma group and healthy control group was analyzed by principal component analysis (PCA), and the sample clustering was good.Then the supervised data is analyzed by partial least squares discriminant analysis, and 500 times of permutation verification is used to prevent the model from overfitting, and the main score is determined at the same time.The statistical model was constructed by orthogonal partial least squares discriminant analysis, and the VIP value jack-knifed confidence interval load map and metabolic contour map were used to screen the differential variables.Finally, 136 differentially metabolites were obtained by removing noise, pseudo-peak isotopes and fragment ions, 29 of which could be found in the database.In this study, the results of lipid analysis of nasopharyngeal carcinoma (NPC) with untreated nasopharyngeal carcinoma (NPC) were compared with those of healthy control group. It was found that it belongs to fatty acids and glycerides.The metabolites of glycerol phospholipids and sphingolipids were significantly higher in patients with nasopharyngeal carcinoma than in healthy controls, while ceramide, which belonged to sphingomyelin, was lower in nasopharyngeal carcinoma than that in healthy controls.Conclusion: a series of lipid small molecule metabolites which can be used as potential diagnostic markers for nasopharyngeal carcinoma were found and the biological significance of differential metabolites was expounded.The mechanism of nasopharyngeal carcinoma (NPC) was further understood by discussing the possible changes in lipid metabolism pathway in patients with nasopharyngeal carcinoma (NPC).
【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】：R739.63

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