Atrx deletion impairs CGAS/STING signaling and increases sarcoma response to radiation and oncolytic herpesvirus
Warren Floyd, … , Diana M. Cardona, David G. Kirsch
Warren Floyd, … , Diana M. Cardona, David G. Kirsch
Published May 18, 2023
Citation Information: J Clin Invest. 2023;133(13):e149310. https://doi.org/10.1172/JCI149310.
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Research Article Oncology

Atrx deletion impairs CGAS/STING signaling and increases sarcoma response to radiation and oncolytic herpesvirus

Abstract

ATRX is one of the most frequently altered genes in solid tumors, and mutation is especially frequent in soft tissue sarcomas. However, the role of ATRX in tumor development and response to cancer therapies remains poorly understood. Here, we developed a primary mouse model of soft tissue sarcoma and showed that Atrx-deleted tumors were more sensitive to radiation therapy and to oncolytic herpesvirus. In the absence of Atrx, irradiated sarcomas had increased persistent DNA damage, telomere dysfunction, and mitotic catastrophe. Our work also showed that Atrx deletion resulted in downregulation of the CGAS/STING signaling pathway at multiple points in the pathway and was not driven by mutations or transcriptional downregulation of the CGAS/STING pathway components. We found that both human and mouse models of Atrx-deleted sarcoma had a reduced adaptive immune response, markedly impaired CGAS/STING signaling, and increased sensitivity to TVEC, an oncolytic herpesvirus that is currently FDA approved for the treatment of aggressive melanomas. Translation of these results to patients with ATRX-mutant cancers could enable genomically guided cancer therapy approaches to improve patient outcomes.

Authors

Warren Floyd, Matthew Pierpoint, Chang Su, Rutulkumar Patel, Lixia Luo, Katherine Deland, Amy J. Wisdom, Daniel Zhu, Yan Ma, Suzanne Bartholf DeWitt, Nerissa T. Williams, Alexander L. Lazarides, Jason A. Somarelli, David L. Corcoran, William C. Eward, Diana M. Cardona, David G. Kirsch

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Figure 4

Atrx deletion leads to persistent DNA DSBs and telomere dysfunction after irradiation.

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Atrx deletion leads to persistent DNA DSBs and telomere dysfunction aft...
(A) Representative images showing 53BP1 Foci (red) and telomere foci (green) in Atrx WT (left) and Atrx KO (right) cell lines 3 days after 4 Gy. White markers show colocalization of telomere FISH foci and 53BP1 foci, which are TIF. Representative images from experiments detailed in C. (B–F) Quantification of an Atrx isogenic cell line pair assayed 3 days after 4 Gy. Each dot represents an experimental repeat immunoFISH experiment of a single isogenic cell line pair with at least 7 images quantified for each experiment. Replicates are Atrx KO + IR (n = 4); Atrx KO untreated (n = 4); Atrx WT + IR (n = 2); and Atrx WT untreated (n = 3). Data are shown for 53BP1 foci (B), 53BP1 and telomere FISH colocalization marking TIFs (C), micronuclei (D), persistent chromosomal bridges between cells (E), and mitotic catastrophe (F). Statistical analysis was performed using a 2-way ANOVA with Tukey’s multiple comparisons test (B–F). (G) DAPI staining showing a chromatin bridge in an Atrx KO cell line treated with 4 Gy and assayed 3 days later. (H) DAPI staining showing a cell undergoing mitotic catastrophe in an Atrx KO cell line treated with 4 Gy and assayed 3 days later. Representative images from experiments detailed in F.