Development of Immunoelectron Microscopy for <scp>VASN</scp> Detection Using Multiple Models and Identification of <scp>VASN</scp> as a Key Regulator of Mitochondrial Homeostasis in Hepatocellular Carcinoma Cells

mice (p < 0.0001). IEM-VASN revealed VASN's organelle-specific distribution, showing significant enrichment in mitochondria in both HCC cells and liver tissues (p < 0.001 and p < 0.0001). Furthermore, murine HCC tissues displayed elevated VASN levels (p < 0.001) alongside reduced mitochondrial counts (p < 0.01). In a chronic aflatoxin B1 (AFB1) exposure model, VASN upregulation correlated with ROS accumulation, mitochondrial membrane potential dissipation, and mitophagy induction. The IEM-VASN method demonstrated high precision and applicability across cellular, animal, and pathological models, providing a powerful tool for elucidating the functional roles of VASN in HCC. These findings establish a highly sensitive and specific IEM technique for characterizing VASN's ultrastructural distribution, highlighting its predominant mitochondrial localization and functional involvement in HCC progression and chemically-induced mitophagy, thus positioning VASN as a critical molecular mediator in liver cancer and mitochondrial homeostasis.