Transcriptional profiling of GBM invasion genes identifies effective inhibitors of the LIM kinase-Cofilin pathway

// Jun-Bum Park 1 , 2 , * , Sameer Agnihotri 1 , * , Brian Golbourn 1 , Kelsey C. Bertrand 1 , Amanda Luck 1 , Nesrin Sabha 1 , Christian A. Smith 1 , Sara Byron 4 , Gelareh Zadeh 1, 3 , Sidney Croul 1 , Michael Berens 4 , James T. Rutka 1 , 5 1 Arthur and Sonia Labatt Brain Tumor Research Centre, Hospital for Sick Children, Toronto, ON. Canada 2 Department of Neurological Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea 3 Division of Neurosurgery, Toronto Western Hospital, University of Toronto, Canada 4 Cancer and Cell Biology Division, Translational Genomics Research Institute, Phoenix, Arizona, United States of America 5 Department of Surgery, University of Toronto, Toronto ON. Canada * Authors contributed equally to this project Correspondence to: Dr. James T. Rutka, e-mail: james.rutka@utoronto.ca Key words: glioblastoma multiforme, invasion, migration, Rho-GTPase, LIM kinase Received: June 19, 2014      Accepted: August 28, 2014      Published: September 05, 2014 ABSTRACT Malignant gliomas are highly proliferative and invasive neoplasms where total surgical resection is often impossible and effective local radiation therapy difficult. Consequently, there is a need to develop a greater understanding of the molecular events driving invasion and to identify novel treatment targets. Using microarray analysis comparing normal brain samples and mesenchymal glioblastoma multiforme (GBM), we identified over 140 significant genes involved in cell migration and invasion. The cofilin (CFL) pathway, which disassembles actin filaments, was highly up-regulated compared to normal brain. Up-regulation of LIM domain kinase 1 and 2 (LIMK1/2), that phosphorylates and inactivates cofilin, was confirmed in an additional independent data set comparing normal brain to GBM. We identified and utilized two small molecule inhibitors BMS-5 and Cucurbitacin I directed against the cofilin regulating kinases, LIMK1 and LIMK2, to target this pathway. Significant decreases in cell viability were observed in glioma cells treated with BMS-5 and Cucurbitacin I, while no cytotoxic effects were seen in normal astrocytes that lack LIMK. BMS-5 and Cucurbitacin I promoted increased adhesion in GBM cells, and decreased migration and invasion. Collectively, these data suggest that use of LIMK inhibitors may provide a novel way to target the invasive machinery in GBM.