While restoration of microRNA-145 (miR-145) expression reduces chemoradioresistance in glioblastoma and suppress prostate cancer proliferation, migration and invasion, the role of miR-145 in response to radiation therapy for prostate cancer is still unknown.
The elevated miR-145 present in invasive glioblastoma cells (IM3 cells) targets and down-regulated srGAP1, thereby allowing downstream G-proteins to remain in their active state and promote the observed invasive phenotype.
In addition, a significantly favorable OS associated with upregulated miR-145 expression was observed in both squamous cell (SCC) (HR = 0.34, 95% CI 0.13 to 0.93) and glioblastoma (HR = 0.72, 95% CI 0.52 to 0.99).
Our study demonstrates that miR-145 has a tumor-suppressive function in glioblastoma in that it reduces proliferation, adhesion, and invasion of glioblastoma cells, apparently by suppressing the activity of oncogenic proteins Sox9 and ADD3.
In addition, we demonstrated a significant inhibition of invasion in silencing experiments with GB-NS shNEDD9 (shNEDD9), and an up-regulation of miR-145 in shNEDD9, suggesting a doublenegative feedback loop between miR-145 and NEDD9.