Brain tumor stem cell dependence on glutaminase reveals a metabolic vulnerability through the amino acid deprivation response pathway
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ABSTRACT: Cancer cells can metabolize glutamine to replenish TCA cycle intermediates, leading to a dependence on glutaminolysis for cell survival. However, a mechanistic understanding of the role that glutamine metabolism has on the survival of glioblastoma (GBM) brain tumor stem cells (BTSCs) has not yet been elucidated. Here we report that, across a panel of twenty glioblastoma BTSC lines, glutaminase (GLS) inhibition showed a variable response – from complete blockade of cell growth to absolute resistance. Surprisingly, BTSC sensitivity to GLS inhibition was a result of reduced intracellular glutamate triggering the amino acid deprivation response (AADR) and not due to the contribution of glutaminolysis to the TCA cycle. Moreover, BTSC sensitivity to GLS inhibition negatively correlated with the expression of the astrocytic glutamate transporters EAAT1 and EAAT2. Blocking glutamate transport in BTSCs with high EAAT1/EAAT2 expression rendered these cells susceptible to GLS inhibition, triggering the AADR, and limiting cell growth. These findings uncover a unique metabolic vulnerability in BTSCs, support the therapeutic targeting of the upstream activators and downstream effectors of the AADR pathway in GBM, and demonstrate that gene expression patterns reflecting the cellular hierarchy of the tissue of origin can alter the metabolic requirements of the cancer stem cell population.
ORGANISM(S): Homo sapiens
PROVIDER: GSE155300 | GEO | 2020/12/25
REPOSITORIES: GEO
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