Tilapia-derived oligopeptide LSGYG inhibits tumor metastasis via electrostatic-lock-like retention at the catalytic region of MMP-2 and suppression of the HIF-1α-mediated EMT-like cascade.

Numerous studies have reported the biological activities of tilapia skin oligopeptides, which exhibit diverse physiological effects. However, research on the relationship between peptide structural characteristics and their activities remains relatively scarce. In this study, we combined computational simulations with biological experiments to investigate the anti-metastatic mechanism of the tilapia skin oligopeptide LSGYG. Computational analyses supported recurrent Zn-neighboring and pocket-associated recognition modes of LSGYG in the catalytic region of matrix metalloproteinase-2 (MMP-2) and identified a dynamically retained pocket-stabilized state with near-Zn anchoring features. Pulling-guided umbrella-window screening further provided qualitative support for a local metastable region near the Zn-adjacent catalytic microenvironment. Subsequent in vitro evaluations demonstrated that LSGYG significantly suppressed migration and invasion in phorbol-12-myristate-13-acetate (PMA)-induced HT1080 cells and reduced metastasis-related molecular signaling in both HT1080 and 143B cells. Mechanistically, LSGYG substantially disrupted extracellular matrix (ECM) remodeling and epithelial-mesenchymal transition (EMT)-like changes by downregulating MMP-2, MMP-9, N-cadherin, Vimentin, and the upstream regulator hypoxia-inducible factor-1α (HIF-1α), while restoring E-cadherin expression. These phenotypic reversals were associated with suppression of reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), and nuclear factor kappa-B (NF-κB) signaling pathways. These findings support LSGYG as a tilapia-derived bioactive peptide candidate for anti-metastatic functional-food or nutraceutical development.