miR-222 targets VGLL4 to promote growth of tongue squamous cell carcinoma

We investigated whether regulation of VGLL4 by miR-222 affects proliferation, migration, invasion, and apoptosis in human tongue squamous cell carcinoma (TSCC) cells. Nanometer Magnetic beads were prepared to extract RNA in CAL27/human oral keratinocytes (HOK). Correlation between expression of miR-222 and VGLL4 in CAL27/human oral keratinocytes (HOK) was analyzed using RT-PCR and western blot. The cellular effects of miR-222/VGLL4 interactions were detected by cck8, transwell, and cell scratch assays, and flow cytometry after miR-222 was silenced or overexpressed in CAL27 cells. We assessed tumor growth in vivo, in a subcutaneous tumor model in mice, and assessed VGLL4 protein expression in tumors by immunohistochemistry. We found that miR-222 expression is higher in CAL27 cells than that in HOK cells. VGLL4 was highly expressed in HOK cells relative to CAL27 cells. When miR-222 was overexpressed, VGLL4 mRNA expression was reduced in CAL27 cells, and protein expression was reduced in the in vivo tumor model. Thus, miR-222 may down-regulate VGLL4 to promote proliferation, migration, and invasion of TSCC cells.