cfDNA methylation pattern in liquid biopsies of testicular seminoma patients

Leo Dumbović¹*, Dora Raos²³⁴ , Nino Sinčić²³⁴, Igor Tomašković¹⁵, Borislav Spajić¹, Miroslav Tomić¹, Davor Ježek⁶, Monika Ulamec³⁴⁷

*presenting author, ¹Clinical Department of Urology, “Sestre milosrdnice” University Hospital Center, Zagreb, Croatia
²Department of Medical Biology and ³Scientific Group for Research on Epigenetic Biomarkers and ⁴Scientific Centre of Excellence for Reproductive and Regenerative Medicine, School of Medicine, University of Zagreb, Croatia, ⁵Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Croatia, ⁶Department of Histology and Embryology, School of Medicine, University of Zagreb, Croatia, ⁷Department of pathology and cytology Ljudevit Jurak, “Sestre milosrdnice” University Hospital Center, Zagreb, Croatia

Testicular seminoma is the most common type of testicular germ cell tumors, routinely diagnosed after orchiectomy. The majority of reported DNA methylation data are obtained on genomic DNA (gDNA) from seminoma tissue, requiring orchiectomy as an invasive procedure. However, analysis of circulating cell-free DNA (cfDNA) from liquid biopsies represents a minimally invasive approach.

This study aimed to investigate whether cfDNA methylation of OCT3/4, KIT, KITLG, and RASSF1A genes from liquid biopsies (blood and seminal plasma), have the potential as novel seminoma biomarkers, as some of those genes are well known for their changed methylation pattern in gDNA of tumorous tissue.

Materials and methods:
cfDNA methylation from liquid biopsies (blood and seminal plasma) from 24 seminoma patients’ samples was assessed by pyrosequencing and compared with healthy volunteers’ samples.

After analyzing panels of specific CpGs, two DNA methylation panels emerged as potential seminoma biomarkers. KITLG from blood and OCT3/4 from seminal plasma.

Although clinical value is yet to be determined, presented data emphasize a potential use of liquid biopsy epigenetic biomarkers in the screening of seminoma patients.