Targeting the TRIB3-MYC axis in cancer: mechanistic insights and therapeutic disruption strategies.

The oncogenic transcription factor MYC drives proliferation, metabolism, and therapy resistance in the majority of human cancers, yet its large, nuclear protein-protein interface has long frustrated direct drug discovery. A pivotal breakthrough was the identification of Tribbles pseudokinase 3 (TRIB3) as a high-affinity scaffold that binds the helix-loop-helix/leucine zipper region of MYC, blocks the E3-ubiquitin-ligase, UBE3B, from tagging critical lysines, and thereby prolongs MYC protein half-life while enhancing MYC-MAX transcriptional output. This review integrates structural, biochemical, and in vivo data to show how genetic deletion or pharmacological eviction of TRIB3 collapses MYC levels, silences its gene program, and suppresses tumor growth in B-cell lymphomas and selected solid tumors. We detail two distinct solid-tumor circuits: (i) inducible TRIB3 overload in KRAS- or EGFR-mutant lung adenocarcinoma that triggers lethal paraptosis when mTOR is inhibited by everolimus plus ginsenoside Rh2; (ii) VHL-controlled UBE3B abundance in breast carcinoma, where loss of VHL renders tumors dependent on TRIB3 shielding for sustained MYC signaling. Emerging therapeutics include helix-mimetic and stapled peptides such as PCM4, fragment-derived small molecules that target a unique Glu344-centered pocket on TRIB3, and PROTAC degraders that either eliminate TRIB3 or hijack it to destroy MYC. When combined with DNA-damaging agents, BET or CDK7 inhibitors, or ligase-restoring strategies, these disruptors produce marked synergy in preclinical models. Remaining translational challenges-efficient intracellular delivery, biomarker-guided patient selection, and off-target surveillance-are increasingly tractable thanks to advances in peptide formulation, AI-accelerated screening, and established regulatory paths for targeted degraders. Collectively, current evidence positions the TRIB3-MYC interface as a druggable Achilles' heel and a realistic gateway to long-sought direct MYC blockade in the clinic.