LncRNA-mediated regulation of SOX9 expression in basal subtype breast cancer cells

Aamira Tariq, Qinyu Hao, Qinyu Sun, Deepak K. Singh, Mahdieh Jadaliha, Yang Zhang, Neha Chetlangia, Jian Ma, Sarah E. Holton, Rohit Bhargava, Ashish Lal, Supriya G. Prasanth, Kannanganattu V. Prasanth

Research output: Contribution to journalArticle

Abstract

Triple-negative breast cancer (TNBC) is one of the most aggressive breast cancer (BC) subtypes with a poor prognosis and high recurrence rate. Recent studies have identified vital roles played by several lncRNAs (long noncoding RNAs) in BC pathobiology. Cell type-specific expression of lncRNAs and their potential role in regulating the expression of oncogenic and tumor suppressor genes have made them promising cancer drug targets. By performing a transcriptome screen in an isogenic TNBC/basal subtype BC progression cell line model, we recently reported ∼1800 lncRNAs that display aberrant expression during breast cancer progression. Mechanistic studies on one such nuclear-retained lncRNA, linc02095, reveal that it promotes breast cancer proliferation by facilitating the expression of oncogenic transcription factor, SOX9. Both linc02095 and SOX9 display coregulated expression in BC patients as well in basal subtype BC cell lines. Knockdown of linc02095 results in decreased BC cell proliferation, whereas its overexpression promotes cells proliferation. Linc02095-depleted cells display reduced expression of SOX9 concomitant with reduced RNA polymerase II occupancy at the SOX9 gene body as well as defective SOX9 mRNA export, implying that linc02095 positively regulates SOX9 transcription and mRNA export. Finally, we identify a positive feedback loop in BC cells that controls the expression of both linc02095 and SOX9. Thus, our results unearth tumor-promoting activities of a nuclear lncRNA linc02095 by facilitating the expression of key oncogenic transcription factor in BC.

Original languageEnglish (US)
Pages (from-to)175-185
Number of pages11
JournalRNA
Volume26
Issue number2
DOIs
StatePublished - Jan 1 2020

Keywords

  • Basal-like subtype
  • Enhancer
  • Nuclear lncRNA
  • Regulation
  • TNBC

ASJC Scopus subject areas

  • Molecular Biology

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  • Cite this

    Tariq, A., Hao, Q., Sun, Q., Singh, D. K., Jadaliha, M., Zhang, Y., Chetlangia, N., Ma, J., Holton, S. E., Bhargava, R., Lal, A., Prasanth, S. G., & Prasanth, K. V. (2020). LncRNA-mediated regulation of SOX9 expression in basal subtype breast cancer cells. RNA, 26(2), 175-185. https://doi.org/10.1261/rna.073254.119