Plecstatin inhibits hepatocellular carcinoma tumorigenesis and invasion through cytolinker plectin

Plecstatin (PST) is a potent anticancer agent in preclinical models, yet its precise mechanism of action and molecular specificity regarding its main targets, plectin and outer dense fiber protein 2 (ODF2), remain incompletely understood. Here, we dissected PST's mode of action using knockouts of plectin (PLEC) and ODF2 in SNU-475 hepatocellular carcinoma (HCC) cells. PST suppressed anchorage-independent growth and impaired 2D and 3D migration in a dose-dependent manner in both wild-type and ODF2-deficient cells, but not in PLEC-deficient cells, establishing plectin as the principal effector of PST's antitumor activity. Proteomic and functional analyses revealed that PST primarily disrupts cytoskeletal remodeling through plectin, while selectively affecting ciliogenesis-related pathways linked to ODF2 loss. Deletion of either protein attenuated PST-induced Ser51 phosphorylation of eIF2α, ATF4/GADD34 induction, and cytochrome c release, indicating cooperative involvement in integrated stress response (ISR). Correlative analysis of patient datasets confirmed associations between PLEC/ODF2 expression and ISR-related gene signatures, supporting the clinical relevance of this pathway. Together, these findings identify plectin as a key target of PST in disrupting cytoskeletal integrity and establish plectin/ODF2 axis in PST-driven stress adaptation in HCC.