HO-1 impairs the efficacy of radiotherapy by redistributing cGAS and STING in tumors
Chuqing Zhang, … , Cheng Xu, Xiaoyu Liang
Chuqing Zhang, … , Cheng Xu, Xiaoyu Liang
Published December 2, 2024
Citation Information: J Clin Invest. 2024;134(23):e181044. https://doi.org/10.1172/JCI181044.
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Research Article Immunology Oncology Article has an altmetric score of 13

HO-1 impairs the efficacy of radiotherapy by redistributing cGAS and STING in tumors

Abstract

Type I IFNs (IFN-Is) induced by radiotherapy (RT) are critical for its efficacy, while the mechanism by which tumor cells inhibit IFN-I production remains largely unsolved. By an unbiased CRISPR screen, we identified hemeoxygenase 1 (HO-1) as an RT-related regulator of IFN-I production. Mechanistically, the ER-anchored, full-length HO-1 disrupted stimulator of IFN genes (STING) polymerization and subsequent coat protein complex II–mediated (COPII-mediated) ER-Golgi transportation, leading to hampered activation of downstream signaling. This process was exacerbated by the upregulation of HO-1 expression under RT. Importantly, RT also induced HO-1 cleavage. Cleaved HO-1 underwent nuclear translocation, interacted with cyclic GMP-AMP synthase (cGAS), and inhibited its nuclear export upon irradiation, leading to suppressed 2′3′-cyclic GMP-AMP (cGAMP) production. Furthermore, we revealed that HO-1 inhibitors could enhance local and distant tumor control of RT in vivo. Clinically, higher HO-1 expression was associated with a poorer prognosis and earlier tumor relapse after RT in multiple types of patient tumors. Collectively, through comprehensive inhibition of the cGAS/STING pathway, HO-1 strongly inhibited RT-induced IFN-I production, and targeting HO-1 was shown to be a promising RT-sensitizing therapeutic strategy.

Authors

Chuqing Zhang, Zhenji Deng, Jiawei Wu, Cong Ding, Zhe Li, Zhimin Xu, Weipeng Chen, Kaibin Yang, Hanmiao Wei, Tingxiang He, Liufen Long, Jun Ma, Cheng Xu, Xiaoyu Liang

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Figure 7

HO-1 inhibits STING oligomerization and consecutive ER-to-Golgi translocation by direct interaction.

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HO-1 inhibits STING oligomerization and consecutive ER-to-Golgi transloc...
(A) Confocal microscopy images of STING and HO-1 in HK1 cells with the indicated treatment. Pearson’s r value was used as a statistical measure to determine the extent of colocalization between HO-1 and STING. (B) The interaction of endogenous HO-1 and STING in HK1 cells was analyzed by immunoprecipitation with the indicated treatment. (C and D) Control, HMOX1-KO, and HMOX1-overexpressing HK1 cells were stained with anti-STING (C and D), anti-calreticulin (C), and anti-GM130 (D) antibodies. Pearson’s r value was used as a statistical measure to determine the extent of colocalization between STING and calreticulin or GM130. (E) The interaction of endogenous STING and TBK1 in HK1 cells was analyzed by immunoprecipitation with the indicated treatment. (F and G) STING polymerization in control and HMOX1-KO HK1 cells with the indicated treatments, followed by native PAGE and SDS-PAGE. (H) HEK293T cells were transfected with the indicated STING mutant plus vector or STING mutant plus HO-1, followed by confocal imaging. (I) HEK293T cells were cotransfected with plasmids expressing HO-1 and STING, or its mutants, followed by native PAGE and SDS-PAGE. (J) HK1 cells were stably transfected with doxycycline-induced (Dox) STING expression plasmids. After doxycycline treatment at the indicated dose, native PAGE for detection of STING polymers and SDS-PAGE were performed. (A) Imaging data were analyzed with Fuji software to reveal colocalization as white dots. (A, C, and D) Pearson’s correlation coefficient was quantified using ImageJ (NIH). n = 10 cells (quantified in a blinded manner). Data are shown as the mean ± SD. Scale bars: 10 μm. **P < 0.01 and ****P < 0.0001 by unpaired, 2-tailed Student’s t test (A) and 1-way ANOVA (C and D).