Diagnostic application of lipidomics fingerprints to bladder carcinoma

Background: Bladder cancer is very diffuse especially in men aged about 65 years and the diagnosis is difficult and invasive. The identification of simple urine biomarkers that will enable diagnosis at an earlier stage of disease and accurately monitor for recurrence is a big challenge. The aim of this research is to find a simple urine test that may substitute or reduce the invasive and expensive cystoscopy. Methods: Voided urines collected in the morning before operation from 25 patients affected by papillary bladder carcinoma (Ta) were used after a short conservation at -80 °C and long conservation for more than 1 year. The lipids were extracted and analyzed using an Agilent Technologies. A statistical analysis of the results was performed with the specific software LipoStar. Results: The results show a clear difference in lipids between patients and controls that can be separated into two groups. In order to identify the lipid species, characteristic fragments of MS/MS spectra were used. On that basis, about 50% of 150 lipids selected were identified. This subset is mainly formed by triacylglycerols, alkyl diacylglycerols, cholesteryl ester and palmitoyl-sphingomyelin that are all present in high quantity in patients' urine. These differences become less evident in samples saved for more than 1 year. Although the dataset is small, it appears that the urine lipids may be used as markers with good specificity and sensitivity. Conclusions: The relevance of lipids in tumorigenesis as well the possible alterations of chromatin lipids are discussed including also the possibility of miRNA influence. The development of a special kit for use in screening and for monitoring the appearance or reappearance of bladder tumors could prevent many deaths due to this disease and may reduce the current invasive and expensive diagnostic system.