Lactylation-stabilized NOL6 promotes colorectal cancer progression via recruiting STAMBP to deubiquitinate YY1 and upregulate MYC transcription

Colorectal cancer (CRC) represents a significant menace to human health, but its molecular pathogenesis remains unclear. Herein, we explored the functional role of Spindle and Nucleolar Protein 6 (NOL6) in CRC progression. In this study, we found NOL6 was significantly overexpressed in CRC tissues, correlated with advanced tumor stages and poor patient prognosis. Mechanistically, NOL6 recruited the deubiquitinating enzyme STAMBP to remove K48-linked polyubiquitin chains from YY1 at lysine 339, preventing YY1 degradation and enhancing c-MYC transcription. A feedback loop was identified where c-MYC directly bound to the NOL6 promoter, reinforcing NOL6 expression. Additionally, lactylation at lysine 54 of NOL6 (K54) stabilized NOL6 by inhibiting its ubiquitination and proteasomal degradation. Targeting NOL6-K54 lactylation with a cell-penetrating peptide inhibitor (K54-pe4) suppressed CRC cell proliferation, migration, and tumor growth in vivo without apparent toxicity. These findings establish a novel regulatory axis (NOL6-STAMBP-YY1-MYC) strengthened by lactylation, highlighting NOL6 as a potential therapeutic target for CRC.