Methyltransferase-like 8 (METTL8) is a RNA methyltransferase that plays a crucial role in mitochondrial translation. Previous study reported that METTL8 is overexpressed in cancer, but whether it contributes to GBM pathogenesis has not been explored. Here, we find that METTL8 is overexpressed in GBM stem cells (GSC) relative to non-cancerous human neural progenitor cells and astrocytes. METTL8 depletion significantly reduces GSC tumorsphere formation, differentiation potential, invasiveness and tumorigenicity. As expected, METTL8 is localized to the mitochondrial matrix of GSC. Although it is established that METTL8 binds to tRNAs, the protein interactors of METTL8 remains uncharacterized. To this end, we aim to define the METTL8 interactome using mitochondrial fractions of 293T cells, and then validate the identified interactors in GSC.