In Vitro Experimental Therapy in Murine Ganglioglioma-Resembling Neoplasms
1 Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn Medical Center
Ganglioglioma (GG) represents the most common, often pediatric glioneuronal tumor entity, preferentially present in the temporal lobe of patients with early-onset focal epilepsy. Histopathologically, they are characterized by dyplastic neuronal and neoplastic astroglial cells. Recently, BRAFV600E has been found in approximately 20-60% of GGs. Moreover, abundantly phosphorylated ribosomal S6 protein (pS6) has been shown reflecting mTOR pathway activation in GGs. Although they are largely low grade (WHO grade I), a small percentage display a more aggressive biology (WHO grade III) and develop into an anaplastic ganglioglioma (aGG), being the dysregulation of TP53 pivotal in this malignant transformation.
Here, we aim to characterize a newly established in vitro model from induced-malignant GG-like murine neoplasms. Co-IU electroporation of BRAFV600E, pAkt and Cre under the control of the CAG promoter at E14 in p53flox/flox mice (BRAFV600E/pAkt/Tp53KO) results in malignant GG-like neoplasms. Following cell dissociation, a tumor cell culture was established and its immunohistochemical analysis at day in vitro 3 (DIV3) showed the presence of dysplastic neuronal and astroglial cells. We also analyzed the proliferation behavior during 13 days and showed that within the first 5 days (DIV1-5) the tumor cells exhibited the maximal proliferation rate assuming to be the optimal time window for future treatments. Moreover, we also tested and optimized the usage of several antibodies against proteins of mTOR and MAPK kinase pathways by using the Western Blot technique. Taking all this data together, we present here a new in vitro tool suitable to quickly test new potential therapeutic options for GGs.
Our work is supported by Else Kröner-Fresenius Promotionskolleg “NeuroImmunology”