Changes in urine metabolite concentration as a minimally invasive marker of ovarian serous adenocarcinoma

Introduction. Detection of ovarian cancer (OC) at the earliest possible stages is a priority for gynecological oncology, since 5-year survival rates decrease significantly with the progression of the disease. Currently, there is a huge need for more effective diagnostic methods and approaches. In recent years, fluid biopsy has received increasing attention in precision medicine because it is minimally invasive and can be repeated many times, allowing for realtime disease monitoring.

Aim. Study of the urine metabolomic profile of patients with ovarian carcinoma.

Materials and methods. To perform metabolomic analysis, 50 urine samples from patients with a diagnosis of serous ovarian carcinoma and 20 samples from apparently healthy individuals were selected. For protein precipitation, 300 mkl of urine was mixed with 600 mkl of a solution of acetonitrile LC-MS (Merck, Germany) and methanol LC-MS (Merck, Germany) (3:1 ratio). Chromatographic separation of metabolites was performed on a Vanquish Flex UHPLC System chromatograph (Thermo Scientific, Germany). The chromatograph was coupled to an Orbitrap Exploris 480 mass spectrometer (Thermo Scientific, Germany) equipped with an electrospray ionization source. Chromatographic separation was carried out on a Hypersil GOLD™ C18 column (1.9mkm, 10 x 2.1 mm) using the following eluents: A, 0.1 % formic acid; B, acetonitrile containing 0.1 % formic acid.

Results. A total of 417 metabolites of various classes were identified by HPLC-MS. It was shown that in the urine of patients with OC 14 metabolites (kynurenine, phenylalanyl-valine, lysophosphatidylcholine (18:3), lysophosphatidylcholine (18:2), alanyl-leucine, lysophosphatidylcholine (20:4), L-phenylalanine, phosphatidylinositol (34:1), 5-methoxytryptophan, 2-hydroxymyristic acid, 3-oxocholic acid, lysophosphatidylcholine (14:0), indoleacrylic acid, lysophosphatidylserine (20:4)) had a significantly higher concentration compared to apparently healthy individuals. The content of 12 compounds, on the contrary, was reduced (L-beta-aspartyl-L-phenylalanine, myristic acid, decanoylcarnitine, aspartyl-glycine, malonylcarnitine, 3-hydroxybutyrylcarnitine, 3-methylxanthine, 2,6-dimethylheptanoylcarnitine, 3-oxododecanoic acid, N-acetylproline, L-octanoylcarnitine, capryloylglycine). This indicates a significant metabolomic imbalance in patients with OC.

Conclusion. The metabolomic profile study of urine by UHPLC-MS showed that in patients with serous ovarian carcinoma there is an imbalance in the content of certain fatty acids and their derivatives, acylcarnitines, phospholipids, amino acids and their derivatives, as well as some derivatives of nitrogenous bases. At the same time, 26 metabolites with abnormal concentrations in urine may have some potential as non-invasive biomarkers of OC in women belonging to high-risk groups.