A Rapid and Comprehensive Targeted Approach for Investigating the Lipidome of Bladder Cancer Subjects.

Bladder cancer is the 10th most common cancer and occurs when abnormal tissue growth develops within the bladder lining. Recent bladder cancer studies suggest that a strict distribution pattern of lipid species and enzymes determine cell fate through regulatory mechanisms. Targeted lipid analysis of plasma samples from bladder cancer patients and healthy subjects was conducted using the LipidQuan platform. LipidQuan package was downloaded from the Waters Targeted Omics Method Library (TOML), which provided all the chromatographic settings and MRM transitions required for lipid analysis. Targeted LC-MS data were acquired in positive and negative ion ESI modes. Over 400 lipids were quantified. Quantification was achieved using calibration curves of plasma spiked with known concentrations of SIL standards prior to extraction. By using surrogate standards prepared and analyzed under identical conditions to those of endogenous lipids, the quantification of endogenous lipids within the same class was achieved. The use of a commercially available, premixed SIL solution per lipid class, rather than a SIL standard for each measured lipid, significantly reduces the overall cost of the study. Deuterated standards were used to assess linear response, with typical R2 values ranging from 0.97 - 0.99 for the various lipid classes in both modes of ionization. Ceramides, LPCs, PCs, and SM are differentially expressed in bladder cancer samples when compared to samples from healthy controls. Pathway analysis revealed a number of components related to inflammation, oxidative stress, and immunity as being significant. A rapid, quantitative lipidomics method (LipidQuan) was deployed for the analysis of plasma in a bladder cancer comparative study. This eliminated method development time and allowed implementation of the methods within minutes. This is of great benefit to a core laboratory. LPCs, Cer, and SM were found to be important markers of bladder cancer.