GSE107243
Downregulation of miR-218-5p promotes invasion of oral squamous cell carcinoma cells via activation of CD44-ROCK signaling
The invasion front of oral squamous cell carcinoma (OSCC) harbors the most aggressive cells of the tumor and is critical for cancer invasion and metastasis. MicroRNAs (miRNAs) play an important role in regulating OSCC invasion. In this study, we modeled the OSCC invasion front on a microfluidic chip and investigated differences in miRNA profiles between cells in the invasion front and those in the tumor mass by small RNA sequencing and bioinformatic analysis. We found that miR-218-5p was downregulated in invasion front cells; a luciferase reporter assay confirmed that cluster of differentiation (CD)44 was a direct target of miR-218-5p. Inhibiting miR-218-5p in invasion front cells activated CD44- Rho-associated protein kinase (ROCK) signaling and promoted cell invasion by inducing cytoskeletal reorganization. These findings indicate that miR-218-5p negatively regulates OSCC invasiveness by targeting the CD44–ROCK pathway and may be a useful therapeutic target for OSCC. Moreover, our method of modeling and isolating invasion front cells using a microfluidic chip is a time-saving alternative to in vivo models. Overall design: The small RNA of the OSCC cells (UM-SCC6) and the invasion front cells of OSCC (UM-SCC6-M) were analyzed by Next Gen RNA Sequencing.