Short-chain acyl post-translational modifications in cancers: Mechanisms, roles, and therapeutic implications.

Post-translational modifications (PTMs) play a pivotal role in epigenetic regulation and are key pathways for modulating protein functionality. PTMs involve the covalent attachment of distinct chemical groups, such as succinyl, crotonyl, and lactyl, at specific protein sites, which alter protein structure, function, stability, and activity, ultimately influencing biological processes. Recently, metabolically derived short-chain acylation modifications (with acyl groups containing fewer than six carbon atoms) have been progressively identified, such as butyrylation, succinylation, crotonylation, and lactylation, differing from traditional acetylation in structure, physicochemical properties, function, and regulation. Aberrant short-chain acyl-PTMs are often associated with tumorigenesis. Research highlights that PTMs like succinylation and lactylation are essential in regulating tumor metabolism, drug resistance, and immune responses. This review elucidates the regulatory mechanisms of eight short-chain acyl-PTMs-butyrylation, succinylation, crotonylation, malonylation, glutarylation, 2-hydroxyisobutyrylation, β-hydroxybutyrylation, and lactylation-that are involved in tumor initiation and progression. Their roles in controlling tumor genomic stability, gene transcription, protein stability, enzyme activity, and nuclear localization are summarized, demonstrating their impact on related biological processes such as tumor metabolism, multi-drug resistance, and immune evasion. Additionally, the review provides an overview of current drug research targeting enzymes that regulate PTMs, offering critical insights to advance therapeutic strategies for cancer treatment.