MicroRNA-31 Regulates Expression of in Both and Human Oral Cancer Cells.

Recent comparative studies have indicated distinct expression profiles of short, non-coding microRNAs (miRNAs) in various types of cancer, including oral squamous cell carcinoma (OSCC). In this study, we employed a hybrid approach using as well as OSCC cell lines to validate putative targets of oral cancer-related miRNAs both in vivo and in vitro. Following overexpression of miR-31, we found a significant decrease in the size of the imaginal wing discs and downregulation of a subset of putative targets, including (), an important regulator of the Wnt signaling pathway. Parallel experiments performed in OSCC cells have also confirmed a similar miR-31-dependent regulation of human that was not initially predicted as targets of human miR-31. Furthermore, we found subsequent downregulation of and , two of the main transcriptional targets of Wnt signaling, suggesting a potential role of miR-31 in regulating the cell cycle and proliferation of OSCC cells. Taken together, our -based in vivo system in conjunction with the human in vitro platform will thus provide a novel insight into a mammal-to--to-mammal approach to validate putative targets of human miRNA and to better understand the miRNA-target relationships that play an important role in the pathophysiology of oral cancer.