miR-147b-mediated TCA cycle dysfunction and pseudohypoxia initiate drug tolerance to EGFR inhibitors in lung adenocarcinoma

Drug tolerance is an acute defence response preceding a fully drug-resistant state and tumour relapse; however, there are few therapeutic agents targeting drug tolerance in the clinic. Here we show that miR-147b initiates a reversible state of tolerance to the epidermal growth factor receptor (EGFR) inhibitor osimertinib in non-small-cell lung cancer. With miRNA-seq analysis, we find that miR-147b is the most upregulated microRNA in osimertinib-tolerant and EGFR-mutated lung cancer cells. Whole-transcriptome analysis of single-cell-derived clones reveals a link between osimertinib tolerance and pseudohypoxia responses irrespective of oxygen levels. Further metabolomics and genetic studies demonstrate that osimertinib tolerance is driven by miR-147b-mediated repression of VHL and succinate dehydrogenase, which are linked to the tricarboxylic acid cycle and pseudohypoxia pathways. Finally, pretreatment with a miR-147b inhibitor delays osimertinib-associated drug tolerance in patient-derived 3D structures. This link between miR-147b and the tricarboxylic acid cycle may provide promising targets for preventing tumour relapse