Next-Generation Sequencing Approach in Methylation Analysis of HNF1B and GATA4 Genes: Searching for Biomarkers in Ovarian Cancer.

DNA methylation is well-known to be associated with ovarian cancer (OC) and has great potential to serve as a biomarker in monitoring response to therapy and for disease screening. The purpose of this study was to investigate methylation of and and correlate detected methylation with clinicopathological characteristic of OC patients. The study group consisted of 64 patients with OC and 35 control patients. To determine the most important sites of and , we used next-generation sequencing. For further confirmation of detected methylation of selected regions, we used high-resolution melting analysis and methylation-specific real-time polymerase chain reaction (PCR). Selected regions of and were completely methylation free in all control samples, whereas methylation-positive pattern was observed in 32.8% () and 45.3% () of OC samples. Evaluating both genes together, we were able to detect methylation in 65.6% of OC patients. We observed a statistically significant difference in methylation between samples with different stages of OC. We also detected subtype specific methylation in and a decrease of methylation in late stages of OC. The combination of unmethylated and methylated was associated with longer overall survival. In our study, we employed innovative approach of methylation analysis of and to search for possible epigenetic biomarkers. We confirmed the significance of the and hypermethylation with emphasis on the need of selecting the most relevant sites for analysis. We suggest selected CpGs to be further examined as a potential positive prognostic factor.