Inhibition of TRIM46 Suppresses Lung Adenocarcinoma Growth by Promoting DUOX2-Mediated Reactive Oxygen Species Production

Abstract

Background: Tripartite motif-containing (TRIM) proteins have been implicated in carcinogenesis. However, the DNA copy-number variation (CNV) of TRIM proteins in lung adenocarcinoma (LUAD) is poorly studied. Methods: We analyzed TRIM gene amplification using The Cancer Genome Atlas (TCGA) LUAD dataset. We investigated the effects of TRIM46 on cell proliferation and apoptosis in vitro and in vivo. TRIM46 binding proteins were identified by immunoprecipitation and mass spectrometry analysis. Findings: Here, the bioinformatics analysis in TCGA LUAD dataset showed that TRIM46 was the most frequently amplified TRIM gene in human LUAD, and that TRIM46 amplification was associated its mRNA expression. The protein and mRNA expression levels of TRIM46 were significantly correlated with the overall survival of LUAD. TRIM46 knockdown suppressed cell proliferation and induced cell apoptosis in LUAD cells, whereas TRIM46 overexpression showed the opposite effects. In addition, TRIM46 knockdown also possessed anti-tumor activity in a xenograft mouse model. DUOX2, a key enzyme involved in reactive oxygen species (ROS) generation, was identified as a binding protein of TRIM46. Knocking down TRIM46 expression reduced DUOX2 ubiquitination, and the ubiquitinated site located on K797 was essential for TRIM46 mediated DUOX2 ubiquitination. Moreover, TRIM46 knockdown-induced cell proliferation inhibition and apoptosis was reversed by DUOX2 knockdown and ROS scavenger (N-acetylcysteine). Interpretation: Our study highlighted the importance of TRIM46 in LUAD tumorigenesis and demonstrated that targeting TRIM46/DUOX2/ROS axis may be a potential therapeutic intervention for the treatment and prevention of LUAD. Funding: Not applicable. Declaration of Interests: These authors have no conflict of interest to declare. Ethics Approval Statement: This study was approved by the Ethical Community of Shanghai Chest Hospital (Shanghai, China). Animal studies were approved by the Animal Care Committee of Shanghai Chest Hospital (Shanghai, China).