1. Oestrogenic regulation of lncRNA at enhancer regions
- Author
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Cathcart, Paul Lewis, Stebbing, Justin, and Castellano, Leandro
- Abstract
Breast cancer is the commonest form of female malignancy with oestrogen receptor positive breast cancer comprising the majority of cases. Despite drastic improvement in treatment over the years, there still is a rising incidence with a significant recurrence rate despite optimal therapy. The molecular biology of cancer cells has advanced rapidly with the advent of genome-wide, high-throughput analytic technologies, revealing that eukaryotic cells are extensively transcribed. This has led to the discovery of a large variety of non-coding RNA (ncRNA) with unknown function. A subset of these ncRNA are transcribed at enhancer regions called enhancer RNAs (eRNA) and have demonstrated importance in transcriptional regulation and cellular function. eRNA are typically located in the nucleus and are monoexonic. By using publicly available GRO-seq, CHIP-seq and our RNA-seq, we identify several eRNAs with multiple exons and isoforms that can be found within the nucleus and cytoplasm. Understanding their function, particularly in the cytoplasm, could lead to the development of future therapies and biomarkers. We have found that these identified eRNAs can be detected by real-time qPCR and increase with oestradiol treatment, with one pair of bidirectionally transcribed eRNAs being close to the gene CCND1. Knockdown of these eRNAs causes a significant reduction in cell growth without any effect on neighbouring genes. Overexpression of eRNAs appear to have no effect on the neighbouring genes and cell growth. Using publicly available data and ribosome profiling experiments, we can confirm that the eRNA are not protein coding but there is potential that they may produce previously unknown small peptides. Finally, we demonstrate by mass spectrometry that one particular eRNA may interact with SUB1. These findings provide a novel insight into uncharacteristic eRNAs that are spliced and located in the cytoplasm and nucleus. Despite having such low expression, they produce significant effects within the cell.
- Published
- 2019
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