Identification of long non-coding RNAs involved in chromosomal instability in a cellular model of prostate cancer

Most of the human genome is transcribed into RNA, but only 2% encodes proteins, leading to a large group of non-coding RNA which, without constitutive RNA, is divided into 2 groups: small (sncRNA) and long (lncRNAs) non-coding RNAs. In this study we used RNA-seq data to identify new lncRNAs which could be involved in chromosomal instability (CIN) in prostate cancer (PCa). Our aim is to study their molecular mechanism and potential role as prognostic biomarkers in this disease.Using RNA-seq data from two prostate cell lines, neoplastic (LNCaP) and non-neoplastic (PrEC), we have identified an unannotated long lncRNA adjacent to CEP55 (centrosomal protein 55), a gene associated with CIN. We have named this 1.6 kb transcript as lncRNA- CEP55. qPCR experiments showed it is downregulated in the neoplastic cell line, in contrast to the adjacent coding gene, CEP55, which is upregulated in the same cell line and downregulated in PrEC. Our data suggest this new lncRNA might be a possible repressor for CEP55. Changes in expression of CEP55 have been associated to CIN in other cancer cell lines.LINC02043 is an annotated lncRNA. We identified a differential expression between PrEC and LNCaP using RNA-seq data. LINC02043 is adjacent to the protein-coding gene RFC4; this gene is associated with CIN in different human cancers. We performed qPCR experiments and found LINC02043 to be downregulated in LNCaP, whereas the adjacent coding gene RFC4 is upregulated; the opposite is found in PrEC cell line. Our findings suggest LINC02043 could have a possible repressor role in RFC4. This protein-coding gene is related to mismatch repair and DNA double-strand break repair, abnormalities in this coding gene have been associated with CIN in other cancer cell lines. LINC02043 could play an important role in the cis-regulation of RFC4.lncRNA-CEP55 and LINC02043 are important targets of study, these lncRNAs could play an essential role in regulating the expression of adjacent genes related to CIN, an enabling characteristic that facilitates the development of the hallmarks of cancer. Further analysis is needed to validate their mechanisms of action and their potential use as prognostic biomarkers in PCa.Particularly in PCa, CIN has lately been related to cancer progression. The role of lncRNAs as drivers of CIN in PCa is a promising field in order to understand PCa progression and may play a potential role as biomarkers in this disease.Citation Format: Rogelio Montiel Manriquez. Identification of long non-coding RNAs involved in chromosomal instability in a cellular model of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3574.