Gries, A. | Search bioRxiv

bioRxiv2023

Repression of Aurora kinase B prevents growth and tissue invasion in medulloblastoma

Novel treatment strategies are required to overcome therapy-associated sequelae in survivors of pediatric medulloblastoma (MB) while maintaining therapeutic efficacy. The tissue impact on drug response in MB is not well understood and drug profiling in the physiological context of the tissue may reveal novel therapy targets. To gain insights into the growth and dissemination behavior of the MB tumor cells under treatment, we combined three-dimensional cell culture screening with ex vivo organotypic cerebellum slice co-culture (OCSC), which allowed assessing tumor cell behavior in the tissue context. We screened a panel of 274 kinase inhibitors and identified aurora kinase B (AURKB) as a potential anti-invasion drug target in MB. We validated tumor suppressive activities of the AURKB inhibitor (AURKBi) barasertib and the structurally unrelated compound GSK-1070916 in cerebellum slice culture models for SHH, Grp3 and Grp4 MB at nanomolar concentrations. We confirmed the necessity of AURKB for tumor growth through genetic suppression of AURKB by siRNA in the tissue context. We revealed that the combination of AURKBi with the SRC/BCR-ABL inhibitor dasatinib acts synergistically to repress tumor growth and invasiveness in the SHH MB cell model ONS76, but not in Grp3 MB cells. Finally, we demonstrate that pharmacological repression of AURKB in the tissue context is as effective as X-ray irradiation to repress tumor growth. Our data highlight that AURKBi is equally efficient as irradiation, suggesting that pharmacological targeting of AURKB may constitute a novel means to overcome radiotherapy limitations in patients younger than three years. Importance of the studyOur data demonstrate anti-tumor activity of AURKB inhibitors in the tissue context for MB tumor cells that are in vitro resistant to the treatment. This indication of a tissue component to drug response contributes critical insights for drug response profiling for brain tumors. AURKB inhibitors barasertib and GSK-1070916 block growth and invasiveness of SHH, Grp3 and Grp4 MB tumor cells as well as primary ATRT. Importantly, AURKBi is equally efficient as irradiation. In conclusion, a tissue component contributes to sensitivity to AURKB inhibition and pharmacological targeting of AURKB may constitute a novel means to overcome radiotherapy limitations in patients younger than three years. Key pointsO_LIAURKB is essential for in tissue growth of MB. C_LIO_LIInactivation of AURKB causes p53 upregulation and decreased in tissue growth and dissemination. C_LIO_LIAURKB inhibition in the tissue context is as effective as irradiation to restrict tumor cell growth. C_LI

cancer biology↗

bioRxiv2021

MAP4K4 determines cancer cell phenotype by controlling the plasma membrane-associated proteome

The composition of the plasma membrane (PM)-associated proteome of tumor cells determines cell-cell and cell-matrix interactions and the response to environmental cues. Whether the PM-associated proteome impacts the phenotype of Medulloblastoma (MB) tumor cells and how it adapts in response to growth factor cues is poorly understood. Using a spatial proteomics approach, we observed that hepatocyte growth factor (HGF)-induced activation of the receptor tyrosine kinase c-MET in MB cells changes the abundance of transmembrane and membrane-associated proteins. The depletion of MAP4K4, a pro-migratory effector kinase downstream of c-MET, leads to a specific decrease of the adhesion and immunomodulatory receptor CD155 and of components of the fast-endophilin-mediated endocytosis (FEME) machinery in the PM-associated proteome of HGF-activated MB cells. The decreased surface expression of CD155 or of the FEME effector Endophilin A1 reduces growth and invasiveness of MB tumor cells in the tissue context. These data thus describe a novel function of MAP4K4 in the control of the PM-associated proteome of tumor cells and identified two downstream effector mechanisms controlling proliferation and invasiveness of MB cells. Graphical abstractc-MET activation upon HGF stimulation induces c-MET internalization and induces downstream MAP4K4 activity. (1) MAP4K4 is required downstream of activated c-MET for the maintenance of surface presentation of CD155 in activated cells. CD155 expression is required for MB cell migration, invasion and proliferation in the tissue context. (2) MAP4K4 is required downstream of activated c-MET to maintain membrane depolarization, possibly by regulating the surface localization of several ion channels and transporters. (3) MAP4K4 is required downstream of activated c-MET cause PM-proximal localization of FEME effector CIP4, FBP17 and CIN85. The FEME effector endophilin A is necessary for MB cell migration, invasion and dissemination.

cell biology↗