Gliomas are characterised by extensive infiltration of the surrounding normal brain parenchyma using neurite-like extensions. Significantly, glioma locomotion is highly similar to invading neural precursor cells. Earlier work has shown that the adhesion adaptor protein NEDD9 promotes active membrane extension in non-neuronal cells, is implicated in neuritogenesis and is enriched in neural precursor cells. Critically, NEDD9 depletion significantly inhibits neural precursor cell migration in vivo and reduces U87MG glioblastoma cell invasion through a brain homogenate. Therefore, we have sought to determine NEDD9 function in glioma cell morphology and 3D cell migration. We first categorized glioblastoma cell lines into mesenchymal, pro-neural and proliferative subtypes via expression of YKL-40 and DLL3. We then used representatives from each that expressed NEDD9 to investigate glioma cell morphology and behaviour. In two-dimensional (2D) culture, NEDD9 depletion caused the loss of microtubule-rich membrane protrusions that were observed in proliferative and mesenchymal cell types. Further, NEDD9 depletion caused increased cell size in 2D and reduced migration speed and persistence in 3D culture in all lines examined. Quantification of morphologies in 3D culture following either NEDD9 depletion or Rac GTPase inhibition revealed no detectable change in rounded versus elongated morphologies. To determine which partner molecules are required for NEDD9 maintenance of cell speed, we screened interacting partners in invading glioblastoma cells. We identified and confirmed the adaptor protein CIN85 as a novel interacting partner of the NEDD9 Src Homology 3 (SH3) domain. Immunofluorescence staining revealed that CIN85 localised to structures involved in cell migration. Our study has revealed that NEDD9 depletion can inhibit migration of lines derived from mesenchymal, pro-neural and proliferative glioblastoma cell types. These findings highlight NEDD9 signalling in glioma as potentially playing a role in the migration of different glioblastoma tumour subtypes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 465. doi:1538-7445.AM2012-465