The CREB-miR-9 negative feedback minicircuitry coordinates the migration and proliferation of glioma cells.

Migration-proliferation dichotomy is a common mechanism in gliomagenesis; however, an understanding of the exact molecular mechanism of this "go or grow" phenomenon remains largely incomplete. In the present study, we first found that microRNA-9 (miR-9) is highly expressed in glioma cells. MiR-9 inhibited the proliferation and promoted the migration of glioma cells by directly targeting cyclic AMP response element-binding protein (CREB) and neurofibromin 1 (NF1), respectively. Our data also suggested a migration-inhibitory role for CREB through directly regulating the transcription of NF1. Furthermore, we found that the transcription of miR-9-1 is under CREB's control, forming a negative feedback minicircuitry. Taken together, miR-9 inhibits proliferation but promotes migration, whereas CREB plays a pro-proliferative and anti-migratory role, suggesting that the CREB-miR-9 negative feedback minicircuitry plays a critical role in the determination of "go or grow" in glioma cells.