Loading...
Targeting DHX9 Triggers Tumor-Intrinsic Interferon Response and Replication Stress in Small Cell Lung Cancer
Murayama, Takahiko Nakayama, Jun Jiang, Xinpei Miyata, Kenichi Morris, Alexander D. Cai, Kathy Q. Prasad, Rahul M. Ma, Xueying Efimov, Andrey Belani, Neel
Murayama, Takahiko
Nakayama, Jun
Jiang, Xinpei
Miyata, Kenichi
Morris, Alexander D.
Cai, Kathy Q.
Prasad, Rahul M.
Ma, Xueying
Efimov, Andrey
Belani, Neel
Citations
Altmetric:
Genre
Journal article
Date
2024-01-03
Advisor
Committee member
Department
Subject
Permanent link to this record
Collections
Files
Research Projects
Organizational Units
Journal Issue
DOI
https://doi.org/10.1158/2159-8290.cd-23-0486
Abstract
Activating innate immunity in cancer cells through cytoplasmic nucleic acid sensing pathways, a phenomenon known as “viral mimicry,” has emerged as an effective strategy to convert immunologically “cold” tumors into “hot.” Through a curated CRISPR-based screen of RNA helicases, we identified DExD/H-box helicase 9 (DHX9) as a potent repressor of double-stranded RNA (dsRNA) in small cell lung cancers (SCLC). Depletion of DHX9 induced accumulation of cytoplasmic dsRNA and triggered tumor-intrinsic innate immunity. Intriguingly, ablating DHX9 also induced aberrant accumulation of R-loops, which resulted in an increase of DNA damage–derived cytoplasmic DNA and replication stress in SCLCs. In vivo, DHX9 deletion promoted a decrease in tumor growth while inducing a more immunogenic tumor microenvironment, invigorating responsiveness to immune-checkpoint blockade. These findings suggest that DHX9 is a crucial repressor of tumor-intrinsic innate immunity and replication stress, representing a promising target for SCLC and other “cold” tumors in which genomic instability contributes to pathology. SIGNIFICANCE: One promising strategy to trigger an immune response within tumors and enhance immunotherapy efficacy is by inducing endogenous “virus-mimetic” nucleic acid accumulation. Here, we identify DHX9 as a viral-mimicry-inducing factor involved in the suppression of double-stranded RNAs and R-loops and propose DHX9 as a novel target to enhance antitumor immunity.
Description
Citation
Takahiko Murayama, Jun Nakayama, Xinpei Jiang, Kenichi Miyata, Alexander D. Morris, Kathy Q. Cai, Rahul M. Prasad, Xueying Ma, Andrey Efimov, Neel Belani, Emily R. Gerstein, Yinfei Tan, Yan Zhou, William Kim, Reo Maruyama, Kerry S. Campbell, Lu Chen, Yibin Yang, Siddharth Balachandran, Israel Cañadas; Targeting DHX9 Triggers Tumor-Intrinsic Interferon Response and Replication Stress in Small Cell Lung Cancer. Cancer Discov 1 March 2024; 14 (3): 468–491. https://doi.org/10.1158/2159-8290.CD-23-0486
Citation to related work
American Association for Cancer Research (AACR)
Has part
Cancer Discovery, Vol. 14, Iss. 3
ADA compliance
Embedded videos
License
Attribution-NonCommercial-NoDerivs CC BY-NC-ND