Autophagy-dependent sensitization effects of PARP inhibitors on recurrent nasopharyngeal carcinoma treated with carbon ion and photon irradiation

• Olaparib significantly enhances radiosensitivity of recurrent nasopharyngeal carcinoma cells to both photon and carbon ion irradiation. • Carbon ion exposure induces an HR-deficient gene signature, increasing susceptibility to PARP inhibition. • Autophagic cell death is the dominant pathway mediating the synergistic cytotoxic effects of olaparib and radiation. • Inhibition of autophagy abolishes the radiosensitization effect, highlighting autophagy as a critical therapeutic target.