Document Type
Article
Publication Date
2-24-2022
Abstract
Background: Mitochondrial dynamics homeostasis is important for cell metabolism, growth, proliferation, and immune responses. The critical GTPase for mitochondrial fission, Drp1 is frequently upregulated in many cancers and is closely implicated in tumorigenesis. However, the mechanism underling Drp1 to influence tumor progression is largely unknown, especially in esophageal squamous cell carcinoma (ESCC).
Methods: Immunohistochemistry was used to examine Drp1 and LC3B expression in tissues of ESCC patients. Autophagic vesicles were investigated by transmission electron microscopy. Fluorescent LC3B puncta and mitochondrial nucleoid were observed by fluorescent and confocal microscopy. Mitochondrial function was evaluated by mitochondrial membrane potential, ROS and ATP levels. Xenograft tumor model was performed in BALB/c nude mice to analyze the role of Drp1 on ESCC progression.
Results: We found that Drp1 high expression is correlated with poor overall survival of ESCC patients. Drp1 overexpression promotes cell proliferation and xenograft ESCC tumor growth by triggering autophagy. Furthermore, we demonstrated that Drp1 overexpression disturbs mitochondrial function and subsequent induces mitochondrial DNA (mtDNA) released into the cytosol thereby inducing cytosolic mtDNA stress. Mechanistically, cytosolic mtDNA activates the cGAS-STING pathway and facilitates autophagy, which promotes ESCC cancer growth. Moreover, mtDNA digestion with DNase I and autophagy inhibition with chloroquine attenuates the cGAS-STING pathway activation and ESCC cancer growth.
Conclusions: Our finding reveals that Drp1 overexpression induces mitochondrial dysfunction and cytosolic mtDNA stress, which subsequently activates the cGAS-STING pathway, triggers autophagy and promotes ESCC progression.
Recommended Citation
Li, Yujia; Chen, Hui; Yang, Qi; Wan, Lixin; Zhao, Jing; Wu, Yuanyuan; Wang, Jiaxin; Yang, Yating; Niu, Menglan; Liu, Hongliang; Liu, Junqi; Yang, Hushan; Wan, Shaogui; Wang, Yanming; and Bao, Dengke, "Increased Drp1 promotes autophagy and ESCC progression by mtDNA stress mediated cGAS-STING pathway." (2022). Department of Medical Oncology Faculty Papers. Paper 176.
https://jdc.jefferson.edu/medoncfp/176
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
PubMed ID
35209954
Language
English
Comments
This article is the author’s final published version in Journal of Experimental and Clinical Cancer Research, Volume 41, Issue 76, February 2022, Pages 1-16.
The published version is available at https://doi.org/10.1186/s13046-022-02262-z. Copyright © Li et al.