Long non-coding RNAs (lncRNAs) appear to be one of the key regulators of cellular signaling processes. According to several authors, they play a crucial role in the regulation of the antitumor immune response. Dysregulation of lncRNA profile is associated with carcinogenesis. Alteration of the lncRNA profile in ovarian cancer (OC) tumor tissue was shown. The aim of our study was to identify serum lncRNAs as potential biomarkers in ovarian cancer.
The study included 34 patients with verified ovarian cancer II-IV FIGO stage. Blood sampling was performed before treatment and after 3 courses of standard neoadjuvant (paclitaxel 175 mg/m² + carboplatin AUC 6 every 3 weeks) chemotherapy. To isolate free-circulating RNA from serum, the SileksMagNA-Direct magnetic particle kit was used. Analysis of the normalized expression of lncRNA MALAT, HOTAIR and PVT1 was carried out using qPCR method with normalization by 18S. We assessed the correlations between lncRNA levels and the patient age, tumor stage and CA-125 level. For statistical analysis, the ANOVA criterion (Statistika 13.0) was used.
We have established strong correlations between the HOTAIR plasma level and age (p = 0.120) and CA-125 level (p = 0.082), and weak correlation with a relapse-free period duration (p = 0.167). The level of MALAT strongly correlated with age (p = 0.050) and with a relapse-free period duration (p = 0.014) and weakly correlated with the stage of ovarian cancer (p = 0.140). PVT1 expression did not reliably correlate with any of the studied clinical and biological parameters.
The revealed relationships between the levels of circulating MALAT and HOTAIR in the blood plasma of patients with OC require further study of these epigenetic regulators in OC carcinogenesis and chemoresistance. Free circulating lncRNA MALAT and HOTAIR, as an element of a liquid biopsy, are potential prognostic and predictive biomarkers for OC.
Clinical trial identification
Legal entity responsible for the study
RFBR (project number 19-315-50012).
All authors have declared no conflicts of interest.