IntroductionGlioblastoma multiforme (GBM) is the most common and aggressive type of glioma with a mean survival of 1 year after diagnosis. A major obstacle in treating GBMs is extensive tumour cell infiltration into the surrounding brain. Despite tumour resection and combined therapy, recurrence occurs due to individual cells that dispersed out of the primary tumour. As this extreme dispersal ability of the tumour cells is a major cause for therapeutic failure, developing novel therapies that target tumour cell dispersal is of high priority. Therefore, there is an urgent need for understanding the molecular mechanisms that contribute to GBM cell motility. The goal of this project is to identify genes that are differentially regulated during GBM cell dispersal and to validate their function in models of dispersal.Material and methodsWe have used an in vitro model of cell motility whereby the dynamics of GBM cell dispersal can be monitored in real-time and quantitated. Accordingly, we isolated motile/migratory/dispersive cells from non-motile/core cells and used these cells for investigating the genes that are differentially regulated during different phases of cell movement by using RNA sequencing. We then conducted loss-of-function experiments to interrogate the role of novel players in GBM dispersal.Results and discussionsAnalysis of the sequencing experiments showed the presence of many differentially expressed genes in motile vs non-motile cells. We found that the survival and proliferation related gene expression profiles were markedly different in motile vs non-motile cells. Most genes that have the highest expression in motile cells compared to non-motile ones were linked to epithelial to mesenchymal transition (EMT) and cell motility based on gene set enrichment analysis. We validated the differential expression of the candidate genes and find the correlation of expression of these genes with glioma patient survival and subtypes of GBM. We also showed the effect of knock-down of candidate genes on cell dispersal. We conducted our experiments both in GBM cell lines and primary established GBM model. Accordingly, we showed that genes involved in EMT are significantly upregulated in our dispersal assay and knockdown of selected genes markedly reduces dispersal in vitro.ConclusionTogether, these studies have the potential to discover novel molecular players of GBM cell dispersal and open up new avenues for designing new therapeutic strategies against the invasive phenotype of otherwise untreatable malignant GBMs.