基于超高效液相色谱-四极杆-静电场轨道阱质谱的结直肠癌患者血清脂质组学研究

Serum Lipidomic Analysis of Colorectal Cancer Patients by Ultra⁃high Performance Liquid Chromatography Tandem Q Exactive Orbitrap Mass Spectrometry

该研究采用超高效液相色谱-四极杆-静电场轨道阱质谱结合主成分分析(PCA)、正交偏最小二乘判别分析(OPLS-DA)对结直肠癌(CRC)患者和健康人的各50例血清样本进行脂质组学分析,通过P<0.05和倍数变化>1.5或<0.67筛选组间差异脂质,利用受试者工作特征曲线(ROC)验证其诊断能力,为基于脂质组学的CRC筛查提供参考。结果表明,两组血清脂质谱存在明显差异,发现155种差异脂质,以磷脂酰胆碱(PC)和甘油三酯(TAG)为主,涉及磷脂酰胆碱代谢和甘油三酯代谢。筛选并鉴定9个脂质标志物,包括棕榈酰乙醇胺、棕榈酸、鞘氨醇、鞘磷脂(SM)d40∶3、SM d36∶0、TAG 58∶1、PC 34∶2、PC 36∶6、PC 38∶7,其ROC曲线面积(AUC)均大于0.80,特异性与灵敏度较高,对于CRC筛查具有较高的临床诊断价值和应用潜力。

Colorectal cancer(CRC)is one of the most malignant tumors in the world and the main cause of cancer death.Traditional diagnostic methods for CRC patients have poor performance owing to their low sensitivity or specificity.The aims of this study are to explore the lipid biomarkers and the metabolic pathways of CRC for better understanding of its pathogenesis as effective and convenient biomarkers for CRC diagnosis are still lacking,and there are relatively few of serum lipidomic study on CRC for the time being.Therefore,the lipidomics analysis on serum samples from 50 normal controls and 50 CRC patients was performed by ultra-high performance liquid chromatography tandem Q Exactive orbitrap mass spectrometry.Lipidomic data was analyzed by univariate statistical analysis,including Mann-Whitney U or Student’t test and multiple statistical analysis,including principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA).In addition,the established OPLS-DA model was validated by 200 times permutation test to exam its fitness and reliability.Through the comparison of lipid profiles,there were significant differences in the serum lipidomics profiles between two groups,and 155 differential lipids were found responsible for their discrimination based on P<0.05 and fold change>1.5 or<0.67.Most of them belonged to phosphatidylcholine(PC)and triacylglycerol(TAG)with constituent ratio of 30.32%and 27.10%,respectively,indicating that dysregulation of PC and TAG metabolism could be closely related with CRC formation.Then,the diagnostic ability of differential lipids was evaluated by receiver operating characteristic curve(ROC)analysis.A total of 9 differential lipids with high specificity and sensitivity as well as high diagnostic performance(AUC>0.80)for CRC diagnosis were selected and identified by using mzCloud and LipidBlast database,including the species of palmitoyl ethanolamide,palmitic acid,sphingosine,sphingomyelin(SM)d40∶3,SM d36∶0,TAG 58∶1,PC 34∶2,PC 36∶6,PC 38∶7.These lipid species,served as the potential diagnostic biomarkers of CRC,exibited a great clinical application potential in serum-based lipidomics screening of CRC.Meanwhile,the study also provided some basic data that could be used to profile the lipid characteristics and explore the mechanism of CRC.