miR-423 Promotes Breast Cancer Invasion by Activating NF-κB Signaling

Ting Dai; Xiaohui Zhao; Yun Li; Lihong Yu; Yanan Li; Xiang Zhou; Qing Gong

doi:10.2147/OTT.S236514

miR-423 Promotes Breast Cancer Invasion by Activating NF-κB Signaling

Onco Targets Ther. 2020 Jun 12:13:5467-5478. doi: 10.2147/OTT.S236514. eCollection 2020.

Authors

Ting Dai^#¹, Xiaohui Zhao^#¹, Yun Li^#², Lihong Yu¹, Yanan Li¹, Xiang Zhou³, Qing Gong¹

Affiliations

¹ GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou 511436, People's Republic of China.
² Department of Immunobiology, Jinan University, Guangzhou 510632, People's Republic of China.
³ Department of Microsurgery, Trauma and Hand Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, People's Republic of China.

^# Contributed equally.

Abstract

Objective: Breast cancer has become the most common malignancy among women worldwide; therefore, novel diagnostic and prognostic markers and therapeutic targets are urgently required. NF-κB signaling plays a pivotal role in enhancing breast cancer malignant phenotypes, especially cancer invasion and metastasis, which is the main cause of death in cancer patients. TNIP2, an important inhibitor of the NF-κB pathway, is known to involve a negative feedback loop of the NF-κB signaling cascade and to regulate tumor aggressiveness in various cancer types. However, the mRNA level of TNIP2 is barely altered in breast cancer; thus, the mechanism that regulates TNIP2 in breast cancer still needs to be elucidated.

Methods: We analyzed the expression and prognosis of miR-423 in a TCGA BRCA miRNA cohort and in clinical specimens. We detected the invasive capacity through a Matrigel-coated Transwell penetration assay, a three-dimensional (3D) spheroid invasion assay and a wound healing assay. Then, we applied luciferase assays, real-time PCR assays and Western blotting to further study the mechanism.

Results: In this study, analysis of the TCGA BRCA miRNA cohort and clinical specimens demonstrated that miR-423 was upregulated in human breast cancers and was positively correlated with clinical stage, poor overall survival and metastasis classification. Moreover, the invasiveness of breast cancer cells was enhanced by ectopic expression of miR-423 and inhibited by miR-423 downregulation. Mechanistically, upregulation of miR-423 led to activation of the NF-κB signaling pathway and elevated expression of snail and twist, while repression of miR-423 inhibited this pathway. Furthermore, the results indicated that TNIP2 is a target gene of miR-423, and suppression of TNIP2 resulted in increased invasiveness in miR-423-silenced cells.

Conclusion: Our results suggest that miR-423 is a crucial factor that enhances breast cancer cell invasion through the NF-κB signaling pathway and shed light on miR-423 as a promising prognostic and therapeutic marker for metastatic breast cancer.

Keywords: NF-κB signaling pathway; TNIP2; breast cancer; miR-423.

Grants and funding

This work was supported by the Provincial Natural Science Foundation of Guangdong (Grant Nos. 2019A1515011201, 2018A030313560, 2020A1515010009), the Education Department of Guangdong Province (Nos. 2019KTSCX137, 2016KTSCX111), National Natural Science Foundation of China (Nos. 81501049, 81502103), Guangzhou Municipal Science and Technology Project (Grant No. 201904010067), the Medical Scientific Research Foundation of Guangdong Province, China (Grant No. A2018354), and Academic Project of Guangzhou Medical University (B185004136).