CircNUP54 promotes hepatocellular carcinoma progression via facilitating HuR cytoplasmic export and stabilizing BIRC3 mRNA.

Abstract

Circular RNAs (circRNAs) have been implicated in tumorigenesis and progression of various cancers. However, the underlying mechanisms of circRNAs in hepatocellular carcinoma (HCC) have not been fully elucidated. Herein, a new oncogenic circRNA, hsa_circ_0070039 (circNUP54), was identified to be significantly upregulated in HCC through circRNA sequencing. As verified in 68 HCC samples, circNUP54 overexpression was correlated with aggressive cancerous behaviors and poor outcomes. Moreover, the function experiments showed that knockdown of circNUP54 inhibited the malignant progression of HCC in vitro and in vivo, whereas overexpression of circNUP54 had the opposite role. Mechanistic investigations carried out by RNA pull-down, RNA immunoprecipitation, and immunofluorescence revealed that circNUP54 interacted with the RNA-binding protein Hu-antigen R (HuR) and promoted its cytoplasmic export. The cytoplasmic accumulation of HuR stabilized the downstream BIRC3 mRNA through its binding to the 3' UTR region. Consequently, the encoded protein of BIRC3, cellular inhibitor of apoptosis 2 (cIAP2), proceeded to activate the NF-κB signal pathway and ultimately contributed to HCC progression. In addition, depletion of BIRC3 rescued the pro-tumorigenic effect of circNUP54 on HCC cells. Overall, this study demonstrated that circNUP54 facilitates HCC progression via regulating the HuR/BIRC3/NF-κB axis, which may serve as a promising therapeutic target for HCC treatment.

• Authors: Chenwei Tang, Hongkai Zhuang, Wentao Wang, Qingbin Wang, Xiaowu Ma, Bingkun Wang, Ziyu Zhang, Jiahao Jiang, Zhiqin Xie, Wenliang Tan, Lei Yang, Songyao Liu, Yonglin Hua, Yuxin Xiao, Baoshan Ding, Yajin Chen, Changzhen Shang
• Journal: Cell death & disease (Cell Death Dis) Vol. 15 Issue 3 Pg. 191 (Mar 05 2024) ISSN: 2041-4889 [Electronic] England
• PMID: 38443362 (Publication Type: Journal Article)
• Copyright: © 2024. The Author(s).

Chemical References

• 3' Untranslated Regions
• Baculoviral IAP Repeat-Containing 3 Protein
• BIRC3 protein, human
• NF-kappa B
• RNA, Circular
• RNA, Messenger
• NUP54 protein, human
• ELAVL1 protein, human

Topics

• Humans
• 3' Untranslated Regions (genetics)
• Baculoviral IAP Repeat-Containing 3 Protein
• Carcinogenesis
• Carcinoma, Hepatocellular (genetics)
• Liver Neoplasms (genetics)
• NF-kappa B (genetics)
• RNA, Circular (genetics)
• RNA, Messenger (genetics)