Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. QKI expression was suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. ShRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of oral squamous cell carcinoma. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected head and neck squamous cell carcinoma and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals. SOURCE: Keunsoo Kang (kangk1204@gmail.com) -  Dankook University

Pluto Bioinformatics

GSE154730: Transcriptome datasets of the Quaking (QKI) gene knock-down human oral squamous cell carcinoma (OSCC) cells