MB-13aCDc FINDS bFGF-INDUCED DISSEMINATION ANTAGONIZED BY TGF-beta IN MEDULLOBLASTOMA CELLS

MB-13. aCDc FINDS bFGF-INDUCED DISSEMINATION ANTAGONIZED BY TGF-beta IN MEDULLOBLASTOMA CELLS Karthiga Santhana Kumar1, Dimitra Tripolitsioti1, Max Pillong2, Jens Kunze2, Gisbert Schneider2, Tarek Shalaby1, Michael Grotzer1, and Martin Baumgartner1; Department of Oncology, University Children’s Hospital, Zurich, Switzerland; Department of Chemistry and Applied Bioscience, ETH Zurich, Zurich, Switzerland Leptomeningeal dissemination (LMD) is the leading cause of death in medulloblastoma (MB), the most prevalent pediatric brain tumour. Understanding the causative events of LMD will be essential for developing targeted anti-LMD therapies. MB research will greatly benefit from a tool that allows rapid identification and quantification of MB cell dissemination under different environmental conditions, including inside three-dimensional matrices. We have established automated cell dissemination counter (aCDc), which combines cell-based assays, automated microscopy for acquisition and software solutions for quantification of imaging data in a single platform for studying MB cell dissemination in high-throughput. aCDc is highly sensitiveand requiresa minimum of 500 cells per condition. It enabled the detection ofgrowth factor-dependent motilityanddisseminationofprimary tumourand patient-derived xenograft MB cells. We identified MB subgroup-specific pro-migratory responses to selected growth factors of excellent diagnostic value. To further reveal synergistic and antagonistic growth factor signalling in MB, we explored the effect of various combinations of growth factors on MB cell motility.We found thatTransforming Growth Factor – b (TGF-b) abrogated cell dissemination induced by the potent pro-migratory basic Fibroblast Growth Factor (bFGF). We ascertained that the distinctive TGF-b and bFGF cross talk in MB is mediated through Extracellular signalregulated kinase 1/2 (ERK 1/2) and rho Kinase (ROCK). We are currently analysing the mediators of this antagonistic signalling to decipher their therapeutic potential for metastatic MB. Together, our data validate aCDc as a novel tool for the identification of promising targets for anti-metastatic therapy in MB. Neuro-Oncology 18:iii97–iii122, 2016. doi:10.1093/neuonc/now076.11 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.