Caractérisation fonctionnelle d'une mutation ponctuelle récurrente récemment découverte dans les gliomes chordoïdes

Chordoid glioma (ChG) is a rare low-grade brain tumor, characterised by a novel recurrent point mutation PRKCA p.D463H, a substitution in the kinase domain of Protein kinase C alpha (PKCα). This study demonstrates the role of this mutated kinase in the development of ChGs. Here we show the inactivation and dominant negative effect of PKCαD463H via in vitro and In cellulo activity assays. Our results show the mutation affects the tertiary structure, resulting in an open, unstable protein. Phosphoproteomic and Co-Immunoprecipitation mass spectrometry data from HEK cells overexpressing PKC⍺D463H show decreased phosphorylation and interaction with proteins involved in cell adhesion. We confirm genetically through single nuclei RNAseq that ChGs derive from specialised tanycytes. By understanding the cell context of tumorigenesis alongside the functional changes of this mutation on the activity and interactome of PKCα, we elaborated a model of the development of ChGs alongside the identification of a therapeutic approach.