miR-223-3p regulates cell growth and apoptosis via FBXW7 suggesting an oncogenic role in human testicular germ cell tumors

miR-223-3p is deregulated in several tumor types and plays an important role in tumorigenesis and progression. However, its role in the pathogenesis of testicular germ cell tumor (TGCT) remains uncharacterized. We previously demonstrated that miR-223-3p expression was increased in TGCTs compared with normal testes (NT), suggesting that miR-223-3p may have an oncogenic role in TGCT. Using published dataset and The Cancer Genome Atlas database, we validated higher miR-223-3p expression in TGCTs than NT, and found a negative correlation between miR-223-3p and FBXW7 mRNA expression levels. Using both gain- and loss-of-function experiments, we show that miR-223-3p regulates FBXW7 protein expression, cell growth and apoptosis in TGCT cell lines. Additionally, we demonstrate that ectopic expression of the full-length coding sequence of FBXW7 could rescue the cell growth and apoptotic effects mediated by miR-223-3p. Our findings suggest an oncogenic role for miR-223-3p in TGCT, which promotes cell growth and inhibits apoptosis through repression of FBXW7.