Cell Reports (Feb 2024)

XRN1 deletion induces PKR-dependent cell lethality in interferon-activated cancer cells

  • Tao Zou,
  • Meng Zhou,
  • Akansha Gupta,
  • Patrick Zhuang,
  • Alyssa R. Fishbein,
  • Hope Y. Wei,
  • Diego Capcha-Rodriguez,
  • Zhouwei Zhang,
  • Andrew D. Cherniack,
  • Matthew Meyerson

Journal volume & issue
Vol. 43, no. 2
p. 113600

Abstract

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Summary: Emerging data suggest that induction of viral mimicry responses through activation of double-stranded RNA (dsRNA) sensors in cancer cells is a promising therapeutic strategy. One approach to induce viral mimicry is to target molecular regulators of dsRNA sensing pathways. Here, we show that the exoribonuclease XRN1 is a negative regulator of the dsRNA sensor protein kinase R (PKR) in cancer cells with high interferon-stimulated gene expression. XRN1 deletion causes PKR pathway activation and consequent cancer cell lethality. Disruption of interferon signaling with the JAK1/2 inhibitor ruxolitinib can decrease cellular PKR levels and rescue sensitivity to XRN1 deletion. Conversely, interferon-β stimulation can increase PKR levels and induce sensitivity to XRN1 inactivation. Lastly, XRN1 deletion causes accumulation of endogenous complementary sense/anti-sense RNAs, which may represent candidate PKR ligands. Our data demonstrate how XRN1 regulates PKR and how this interaction creates a vulnerability in cancer cells with an activated interferon cell state.

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