Targeting USP7 lactylation suppresses NSCLC tumorigenesis by promoting PINK1 ubiquitination and degradation

Lactylation is an emerging post-translational modification that is well established for its involvement in epigenetic regulation. However, its functional significance and regulatory mechanisms in non-small cell lung cancer (NSCLC) remain poorly understood. In this study, integrated proteomic and lactylomic analyses of clinical NSCLC specimens and matched adjacent normal tissues showed that USP7 (ubiquitin specific peptidase 7) was upregulated and USP7 K1084 lactylation was increased in NSCLC. Knockout of USP7 or inhibition of USP7 lactylation impaired cellular mitophagy, resulting in mitochondrial damage and attenuated NSCLC tumorigenicity. We identified CREBBP/CBP (CREB binding lysine acetyltransferase) as the key lactyltransferase responsible for USP7 K1084 lactylation. USP7 lactylation induced its localization to mitochondria and increased its interaction with PINK1 (PTEN induced kinase 1), promoting PINK1 deubiquitination and stabilization. Pharmacological inhibition of CREBBP reduced USP7 lactylation levels and promoted PINK1 ubiquitination and degradation, exerting antitumor effects in vitro and in vivo. Analysis of NSCLC clinical specimens showed that the protein levels of USP7, CREBBP, and PINK1 were positively correlated, and their high expression was associated with poor patient prognosis. Collectively, our findings establish the CREBBP-USP7-PINK1 axis as a promising therapeutic target for NSCLC treatment. Abbreviations: CHX: cycloheximide; CREBBP/CBP: CREB binding lysine acetyltransferase; DUB: deubiquitinating enzyme; IHC: immunohistochemistry; IP: immunoprecipitation; KO: knockout; LDHA: lactate dehydrogenase A; MS: mass spectrometry; NALA: L-sodium lactate; NSCLC: non-small cell lung cancer; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; PINK1: PTEN induced kinase 1; PLA: proximity ligation assay; ROS: reactive oxygen species; shRNA: short hairpin RNA; TEM: transmission electron microscopy; TUBE: tandem ubiquitin binding entity; UPS: ubiquitin-proteasome system; USP7: ubiquitin specific peptidase 7; WT: wild type.