Increased amounts and stability of telomeric repeat-containing RNA (TERRA) following DNA damage induced by etoposide

PLoS One. 2019 Nov 22;14(11):e0225302. doi: 10.1371/journal.pone.0225302. eCollection 2019.

Abstract

Telomeric repeat-containing RNAs (TERRAs) are long noncoding RNAs transcribed from subtelomeres toward telomeric repeat tracts, which have been implicated in telomere protection and heterochromatin formation. Genotoxic stress leads to upregulation of TERRAs. However, the mechanism of DNA damage-mediated TERRA induction remains elusive. Here, we treated HeLa cells with etoposide, a DNA double-strand break-generating agent, for various times and monitored the levels of TERRAs. Etoposide treatment led to a gradual time-dependent increase in TERRAs. Etoposide-mediated induction was evident in many TERRAs arising from various chromosome loci, including 20q and XpYp. Chromatin immunoprecipitation assays revealed no significant changes in the occupancy of RNA polymerase II at telomeres upon etoposide treatment. Interestingly, TERRAs arising from 20q, XpYp, 10q, and 13q degraded at slower rates in cells treated with etoposide, while degradation rates of TERRAs from many loci tested were nearly identical in both etoposide- and mock-treated cells. Telomere damage occurred from early time points of etoposide treatment, but telomere lengths and abundance of telomeric repeat-binding factor 2 (TRF2) at telomeres remained unchanged. In summary, etoposide treatment led to telomere damage and TERRA accumulation, but telomere lengths and TRF2-mediated telomere integrity were maintained. Etoposide-mediated TERRA accumulation could be attributed partly to RNA stabilization. These findings may provide insight into the post-transcriptional regulation of TERRAs in response to DNA damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents, Phytogenic / adverse effects*
  • Cell Survival / drug effects
  • Chromosomes, Human, Pair 20 / genetics
  • Chromosomes, Human, X / genetics
  • Chromosomes, Human, Y / genetics
  • DNA Damage*
  • Etoposide / adverse effects*
  • Gene Expression Regulation, Neoplastic / drug effects
  • HeLa Cells
  • Humans
  • RNA Stability
  • RNA, Long Noncoding / chemistry
  • RNA, Long Noncoding / genetics*
  • Telomere / drug effects
  • Telomere / genetics*
  • Telomeric Repeat Binding Protein 2

Substances

  • Antineoplastic Agents, Phytogenic
  • RNA, Long Noncoding
  • TERF2 protein, human
  • Telomeric Repeat Binding Protein 2
  • Etoposide

Grants and funding

This work was supported by the Basic Science Research Program through the National Research Foundation (NRF) funded by the Ministry of Education (2014R1A1A2054542 to BKO) and by NRF funded by the Ministry of Science and ICT (2017R1A2B4004721 to BKO) of Republic of Korea. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.