基质柔软度和流体剪切力通过TRPV4促进卵巢癌干性、致瘤性和转移

Matrix stiffness and fluid shear force are key mechanical cues in ovarian cancer microenvironment that can impact cancer stemness, tumorigenicity and metastasis. However, the molecular identity of mechanosensors and/or mechanosensitive mediators that can be respond to matrix stiffness and fluid shear force in ovarian tumor microenvironment is unclear. TRPV4 is a mechanosensitive Ca 2+ -permeable channel expressed in ovarian cancer cells. In the present study, we used 3D fibrin gel to enrich ovarian cancer stem cell (OCSC)-like cells. We found that matrix softness can increase the expression level of TRPV4 in OCSC-like cells. The activity of TRPV4 subsequently stimulates the growth of OCSC-like cells in tumor spheroids and increases the expression of OCSC markers in vitro, and promotes the growth of tumor xenografts in NOD/SCID mice in vivo. Atomic force microscope measurement of patients' samples and spatial transcriptome analysis of ovarian tumor database demonstrated that softer tumor regions have lower TRPV4 expression. Light-induced photolysis of 3D CarHc hydrogel, which rapidly dissipates the gel stiffness, elicited a TRPV4-mediated Ca 2+ transient in the gel-encapsulated OCSC-like cells. Furthermore, we found that TRPV4 activity has positive feedback regulation on its own expression and that matrix softness may act through integrin beta3 to stimulate TRPV4 activity. In another series of experiments, fluid shear force was found to directly stimulates the activity of TRPV4 channels, consequently elevating the expression level of OCSC markers, and promoting transwell migration of OCSC-like cells in vitro and peritoneal tumor metastasis in vivo. Taken together, the present study provides strong evidence that soft matrix and fluid shear act though mechanosensitive TRPV4 channels to promote ovarian cancer stemness, consequently aggravating ovarian cancer malignancy.