AUTHOR=Ma Chuan , Shi Tingting , Qu Zhuli , Zhang Aobo , Wu Zuping , Zhao Huaqiang , Zhao Haoming , Chen Hongyu 

TITLE=CircRNA_ACAP2 Suppresses EMT in Head and Neck Squamous Cell Carcinoma by Targeting the miR-21-5p/STAT3 Signaling Axis

JOURNAL=Frontiers in Oncology

VOLUME=Volume 10 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.583682

DOI=10.3389/fonc.2020.583682

ISSN=2234-943X

ABSTRACT=CircRNAs contain microRNA (miRNA) specific binding sites and can function as miRNA sponges to regulate gene expression by removing the inhibitory effect of an miRNA on its target gene. MiR-21-5p has been reported to be involved in the development of Head and Neck Squamous Cell Carcinoma (HNSCC) and plays an active role in the activation of epithelial-mesenchymal transition (EMT). However, the upstream regulatory mechanism and downstream targets of miR-21-5p in tumor cells remains unknown. CircRNA_ACAP2 inhibits the function of miR-21-5p through binding to its specific binding sites in HNSCC cells. Overexpression of CircRNA_ACAP2 inhibits the proliferation and migration of HNSCC cells, while downregulation of CircRNA_ACAP2 does the opposite. STAT3 is a direct target gene of miR-21-5p and a transcription factor of ZEB1. We improve that CircRNA_ACAP2 functions as a tumor suppressor gene in HNSCC, and its function is regulated via miR-21-5p/STAT3 signal axis.