Relevance. Breast cancer (BC) remains one of the leading causes of cancer deaths among women worldwide. However, so far very little is known about the exact mechanisms of the occurrence of this type of cancer and the regulation of carcinogenesis, which complicates the diagnosis, prognosis and therapy. Recently, studies of long non-coding RNAs (lncRNAs) involved in the regulation of various signaling pathways in cells have become increasingly important, since they demonstrate great prognostic potential in cancer.

The aim of our work was to identify new aberrantly expressed long non-coding RNAs in breast cancer.

Materials and methods. Total RNA was isolated from paired breast cancer samples according to the standard method. Analysis of the expression of 84 lncRNAs in tumor and histologically normal adjacent breast tissue was performed using RT² lncRNA PCR Arrays (LAHS-002Z, QIAGEN). Additionally, data on lncRNAs expression in breast cancer from the GEPIA database (http://gepia.cancer-pku.cn/) were analyzed.

Results. We have identified 30 aberrantly expressed lncRNAs in breast cancer. For most lncRNAs, a decrease in the expression level by 2.34–13.2 times (p<0.05) was noted, and only for lncRNA TERC, an increase in the expression level by 2.24 times (p=0.034) was noted. Of greatest interest are the data obtained for lncRNAs ADAMTS9-AS2, EMX2OS, HOTAIRM1 and MEG3, as they are consistent with the data of bioinformatics analysis. However, further studies of larger group of samples are needed to evaluate the biomarker potential of the identified lncRNAs in breast cancer.

Conclusions. Experimental and bioinformatic analysis of changes in lncRNA expression in breast cancer revealed lncRNAs TERC, ADAMTS9-AS2, EMX2OS, HOTAIRM1, and MEG3 with biomarker potential.

This work was supported by the Russian Science Foundation grant no. 22-75-00132.