Circ6834 suppresses non-small cell lung cancer progression by destabilizing ANHAK and regulating miR-873-5p/TXNIP axis

• Published in: Molecular cancer Vol. 23; no. 1; pp. 128 - 16
• Main Authors: Wang, Maoye, Ding, Xiaoge, Fang, Xinjian, Xu, Jing, Chen, Yanke, Qian, Yu, Zhang, Jiahui, Yu, Dan, Zhang, Xiaoxin, Ma, Xiuqin, Zhu, Taofeng, Gu, Jianmei, Zhang, Xu
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 18-06-2024; BioMed Central; BMC
• Subjects: Animals; Carcinoma, Non-Small-Cell Lung - genetics; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Line, Tumor; Cell Movement - genetics; Cell Proliferation; circ6834; CircRNA; Development and progression; Disease Progression; Epithelial-Mesenchymal Transition - genetics; Female; Gene expression; Gene Expression Regulation, Neoplastic; Genes; Health aspects; Humans; Luciferase; Lung cancer, Non-small cell; Lung cancer, Small cell; Lung Neoplasms - genetics; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Male; Metastasis; Mice; MicroRNAs - genetics; NSCLC; Progression; Protein binding; RNA; RNA, Circular - genetics; Scientific equipment and supplies industry; Signal Transduction; TGF-β; Therapeutic target; Transforming Growth Factor beta - metabolism; Transforming growth factors; Ubiquitin; United States; China; Progression; TGF-β; NSCLC; CircRNA; circ6834; Therapeutic target
• ISSN: 1476-4598; 1476-4598
• DOI: 10.1186/s12943-024-02038-3

Circular RNAs (circRNAs) play important roles in cancer progression and metastasis. However, the expression profiles and biological roles of circRNAs in non-small cell lung cancer (NSCLC) remain unclear.
In this study, we identified a novel circRNA, hsa_circ_0006834 (termed circ6834), in NSCLC by RNA-seq and investigated the biological role of circ6834 in NSCLC progression in vitro and in vivo. Finally, the molecular mechanism of circ6834 was revealed by tagged RNA affinity purification (TRAP), western blot, RNA immunoprecipitation, dual luciferase reporter gene assays and rescue experiments.
Our results showed that circ6834 was downregulated in NSCLC tumor tissues and cell lines. Circ6834 overexpression inhibited NSCLC cell growth and metastasis both in vitro and in vivo, while circ6834 knockdown had the opposite effect. We found that TGF-β treatment decreased circ6834 expression, which was associated with the QKI reduction in NSCLC cells and circ6834 antagonized TGF-β-induced EMT and metastasis in NSCLC cells. Mechanistically, circ6834 bound to AHNAK protein, a key regulator of TGF-β/Smad signaling, and inhibited its stability by enhancing TRIM25-mediated ubiquitination and degradation. In addition, circ6834 acted as a miRNA sponge for miR-873-5p and upregulated TXNIP gene expression, which together inactivated the TGF-β/Smad signaling pathway in NSCLC cells.
In conclusion, circ6834 is a tumor-suppressive circRNA that inhibits NSCLC progression by forming a negative regulatory feedback loop with the TGF-β/Smad signaling pathway and represents a novel therapeutic target for NSCLC.