miR-7 and miR-214 are specifically expressed during neuroblastoma differentiation, cortical development and embryonic stem cells differentiation, and control neurite outgrowth in vitro

The mammalian nervous system exerts essential control on many physiological processes in the organismand is itself controlled extensively by a variety of genetic regulatory mechanisms. microRNA (miR),an abundant class of small non-coding RNA, are emerging as important post-transcriptional regulators ofgene expression in the brain. Increasing evidence indicates that miR regulate both the development andfunction of the nervous system. Moreover, deficiency in miR function has also been implicated in a numberof neurological disorders. Expression profile analysis of miR is necessary to understand their complexrole in the regulation of gene expression during the development and differentiation of cells. Here wepresent a comparative study of miR expression profiles in neuroblastoma, in cortical development, andin neuronal differentiation of embryonic stem (ES) cells. By microarray profiling in combination with realtime PCR we show that miR-7 and miR-214 are modulated in neuronal differentiation (as compared tomiR-1, -16 and -133a), and control neurite outgrowth in vitro. These findings provide an important steptoward further elucidation of miR function and miR-related gene regulatory networks in the mammaliancentral nervous system.