ATF4-Mediated Metabolic Stress Response as a Therapeutic Vulnerability in Chordoma [PDX RNA-seq]

Chordoma, a rare and challenging primary bone malignancy, currently lacks effective targeted therapies. Despite surgical resection and adjuvant radiotherapy, prognosis remains poor. Recent preclinical studies have highlighted potential therapeutic targets, including the transcription factor TBXT, although clinical outcomes have been modest. In this study, we investigated the therapeutic potential of tRNA synthetase inhibitors, specifically halofuginone and halofuginol, in chordoma treatment. We conducted extensive drug screening, identifying these compounds as effective in reducing cell viability in chordoma cell lines through an ATF4-mediated stress response rather than TBXT regulation. Our findings were validated using RNA sequencing, which revealed significant upregulation of ATF4 and associated stress response genes. Additionally, halofuginone demonstrated significant tumour growth inhibition in an in vivo patient-derived xenograft model. These results suggest that targeting metabolic stress pathways via ATF4 activation presents a novel therapeutic approach for chordoma, warranting further clinical investigation.