Abstract (eng)
Ovarian cancer is the eighth most common female cancer worldwide and compared to other gynecologic malignancies, ovarian cancer has the highest mortality rate. The accumulation of ascitic fluids in the peritoneal cavity is associated with a worse prognosis and a more aggressive course. In addition, extracellular vesicles (EVs) circulating within the ascitic fluids, participate in the intercellular crosstalk in the tumour microenvironment. Since metabolic alteration is one of the hallmarks of cancer, and so far, studies of EVs have mostly focused on proteomics and transcriptomics, it is essential to study the metabolome of EVs. This work aimed to detect and analyse the metabolomic profile of biofluids, namely ascitic fluids and peritoneal washes, of ovarian cancer patients and of the corresponding isolated EVs. For this, a method with the use of the AbsoluteIDQ® p180 metabolomic kit (Biocrates), coupled with an LC-MS system and FIA analysis was implemented in the lab. After the successful implementation of the method, 155 metabolites were identified in the ascitic fluids and peritoneal washes. A smaller number of 69 metabolites could be detected in the EVs from ascitic fluids and 43 metabolites in EVs from the peritoneal washes. Multivariate data analysis such as principal component analysis and hierarchical clustering analysis shows that no significant differences between the two biofluids or between their EVs could be found. Nevertheless, the metabolic yield of the biofluids differed significantly from the EVs concerning 1) the metabolite classes and 2) the quantifications of metabolites. Only in the biofluids amino acids, biogenic amines and acylcarnitines were quantified, whereas the EVs were enriched in lipids such as sphingomyelins and phosphatidylcholines. A follow-up analysis could include patient information such as age, treatment, and relapse, to find biomarkers for diagnosis, prognosis, and support more targeted treatment.