Data from Adaptive Regulation of dNTP Homeostasis Confers Osimertinib Resistance in EGFR-Mutant Non–Small Cell Lung Carcinoma
Year: 2026
Type: other
Abstract: Maintaining sustained deoxyribonucleotide triphosphate (dNTP) pools is essential for DNA replication fidelity and genome stability. In EGFR-mutant non–small cell lung carcinoma (NSCLC), we find that disruption of dNTP homeostasis plays a critical role in determining sensitivity to the EGFR inhibitor osimertinib (Osi) and in shaping mechanisms of acquired resistance. Transcriptomic and biochemical analyses revealed that Osi suppresses RRM2 expression, a key regulator of dNTP synthesis, through downregulation of the transcription factor MYBL2. In response to Osi-mediated replication stress and dNTP depletion, cells activated a compensatory pathway involving the stress-inducible ribonucleotide reductase subunit RRM2B via a novel transcriptional regulator, TNNT3. We further identified CHK2 signaling as essential for TNNT3 nuclear translocation and RRM2B transcriptional activation. Inhibition of CHK2 or combined CHK1/2 blockade impaired RRM2B induction, exacerbated replication stress, and delayed the development of Osi resistance both in vitro and in xenograft models. Collectively, these findings reveal that EGFR-mutant NSCLC cells rely on a dynamic EGFR–MYBL2–RRM2 and CHK2–TNNT3–RRM2B regulatory axis to maintain dNTP pool balance under therapeutic pressure. Disruption of this axis sensitizes tumors to Osi and impairs the acquisition of resistance, highlighting dNTP metabolism as a critical vulnerability and actionable target in EGFR-driven lung cancer. Significance: Targeting dNTP metabolism sensitizes EGFR-mutant NSCLC to osimertinib treatment and delays drug resistance, revealing a novel and actionable therapeutic vulnerability in EGFR-driven lung cancer.
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
OpenAlex ID: W7167089395
Cites:
Cited by:
Related to: