Aberrant expression of a long non-coding RNAs group in ovarian cancer

Abstract

Background. Ovarian cancer (OC) is a group of aggressive heterogeneous malignant tumors characterized by rapid progression, low diagnostic potential, high incidence of adverse outcomes, and high potential for metastasis. Recently, studies of long non-coding RNAs (lncRNAs), which, with rare exceptions, do not have the ability to encode proteins, have become increasingly important. LncRNAs are characterized by high tissue-specific expression and they are involved in the regulation of various signaling pathways in cells and demonstrate a great prognostic potential in cancer. Aim. Detection of aberrantly expressed long non-coding RNAs in tumor samples from OC patients and association of expression levels with pathophysiological characteristics of tumors. Methods. Samples of OC tumors were collected and clinically characterized at the N.N. Blokhin Research Institute of Clinical Oncology. High molecular weight RNA was isolated from tissue by a standard method. Analysis of the expression levels of HOTAIR, MALAT1, and TINCR lncRNA was carried out using real-time PCR and a qPCRmix-HS SYBR ready-made reaction mixture (Evrogen). Statistical analysis of expression levels was performed in the R software environment using the nonparametric Mann-Whitney U test. Correlation analysis was performed using Spearman's rank correlation, and its significance level was calculated. Differences were considered significant at p<0.05. Additionally, expression levels of these lncRNAs in OC were analyzed using the GEPIA database (http://gepia.cancer-pku.cn/). Results. The expression levels of the HOTAIR and MALAT1 lncRNA genes were significantly decreased (p≤0.05). Analysis of the samples with the account of the tumor pathophysiological characteristics showed that the decrease in the level of HOTAIR expression was associated with stage III/IV of the tumor process. For MALAT1 and TINCR lncRNAs, low expression levels significantly correlated with the development of the endometrioid subtype of OC. Conclusion. The results of the study allow a better insight into the mechanisms of OC development and can be used for diagnosis, prognosis and selection of therapeutic tactics in this pathology.