MiR-365b-3p, down-regulated in retinoblastoma, regulates cell cycle progression and apoptosis of human retinoblastoma cells by targeting PAX6.

PAX6 contributes to the development and progression of retinoblastoma (RB), but the molecular mechanism underlying the regulation of PAX6 expression is unclear. Here we found that microRNA-365b-3p (miR-365b-3p) is downregulated in human RB tissues. Ectopic expression of miR-365b-3p significantly attenuates cell growth, induces cell cycle arrest in G1 phase and cell apoptosis through inhibiting the expression of PAX6 by directly binding its 3' untranslated regions. Furthermore, overexpression of miR-365b-3p upregulates p21 and p27 but downregulates cdc2 and Cyclin D1 protein levels. Elucidating the regulatory mechanism of PAX6 by microRNAs may give new clues to the therapy against RB.