[Ascites May Provide Useful Information for Diagnosis of Ovarian Cancer]

Ovarian cancer is the most lethal gynecological cancer, almost 80% of all patients succumb the disease within 5 years of diagnosis. High mortality is caused especially by nonspecific symptoms, diagnosis in late stages and the absence of a specific biomarker. Currently, the most common diagnostic biomarkers are the membrane glycoprotein Cancer Antigen 125 (CA 125), the Human Epididymal Protein 4 (HE4) and the Carcinoembryonic Antigen (CAE). None of these biomarkers is specific only for ovarian cancer and increased levels may be caused by other diseases. Therefore, current research is focused on finding new biomarkers for diagnosis and prognosis of ovarian cancer. Interesting clinical material is ascites, the fluid accumulated in abdominal cavity, which is typical for ovarian cancer and it is present in almost 90% of all cases of stage III and IV.

For this study, samples of ascites from patients with benign and malignant ovarian tumors were used. For full glycomic and proteomic analysis, only 5 µL of ascites were used. Glycans were released from proteins by the enzyme PNGase F and proteins were digested to peptides by trypsin. Samples were purified and measured using a mass spectrometer.

Glycan and protein profiles of patients with benign and malignant ovarian cancer were compared. In patient with a benign tumor, more simple glycans with lowm/z were increased while in the patient with a malignant tumor, higher, more complex glycans were increased. In the malignat tumor in comparison to benign tumor, 127 unique proteins were identified, especially proteins of the annexin, mucin and peroxiredoxin families.

This investigation is a pilot study focused on comparison of protein and glycan composition of ascites in patients with benign and malignant ovarian cancer. Significant differences were found on both glycan and protein levels. Results will be verified on a larger set of patients and compared with a set of control samples.Key words: glycomics - proteomics - ascitic fluid - ovarian cancer This study was supported by projects of the Ministry of Education Youth and Sports - National Sustainability Program I - LO1413; Ministry of Health, Czech Republic - conceptual development of research organization (MMCI, 00209805); Czech Science Foundation 16-04496S. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 13. 3. 2017Accepted: 26. 3. 2017.