Mechano-regulation of Endocytosis as a Strategy to Sensitize Cancer Cells to Fas-induced Apoptosis

Fas, a transmembrane death receptor, triggers apoptosis upon binding its ligand, FasL. Despite high Fas expression in cancer cells, low surface localization desensitizes them to Fas-induced apoptosis. We show that inhibiting endocytosis enhances Fas microaggregate formation on the plasma membrane, increasing cancer cell sensitivity to Fas-induced apoptosis. We increased membrane tension using the Rho-kinase inhibitor fasudil, reducing endocytosis dynamics as demonstrated by confocal microscopy and optical tweezers. When combined with soluble FasL (sFasL), fasudil significantly promoted apoptosis in cancer cells, while nonmalignant cells were less affected. In 3D models, the fasudil-sFasL combination inhibited glioblastoma growth in stem cell-derived brain organoids and induced tumor regression in a xenograft mouse model. These results highlight the potential of mechano-inhibition of endocytosis as a novel strategy for sensitizing cancer cells to apoptosis, offering promise for targeted cancer therapies.