KEAP1-mediated mitochondrial remodeling on stiffness-graded collagen substrates drives hepatocellular carcinoma...

Mechanical and structural cues of the extracellular matrix (ECM) regulate tumor cell metabolism and drug response, yet the molecular mediators that link these biophysical signals are unclear. We present an elastically supported surface platform bioengineered with varying stiffness and collagen fiber anisotropy to replicate the fibrotic and mechanically inhomogeneous liver cancer microenvironment. Using this system, we identify Kelch-like ECH-associated protein 1 (KEAP1) as a mechanoresponsive mediator linking ECM stiffness to mitochondrial dynamics, redox adaptation, and chemoresistance in hepatocellular carcinoma (HCC). In substrate stiffness increase, biphasic KEAP1 expression, time-dependent mitochondrial remodeling via a KEAP1-BCL-2-DRP1 cascade, suppression of reactive oxygen species, and activation of antioxidant and glycolytic transcriptional programs were triggered. RNA sequencing revealed stiffness-dependent repression of mitochondrial fission genes and induction of AGE-RAGE signaling. At a functional level, cells grown in stiffer matrix demonstrated augmented proliferation and chemoresistance to cisplatin and sorafenib with nuclear translocation of NRF2. Multiplex imaging of human HCC tissues confirmed that collagen-rich regions co-localize with high KEAP1 and TOM20 expression, confirming the in vitro findings. This study demonstrates ECM stiffness to be a bioactive material property that guides mitochondrial and redox networks through KEAP1 signaling, and the mechanically tunable collagen platforms to be of a utility for dissection and manipulation of tumor adaptation mechanisms.