Fig. 2

Matrix stiffness modulates ovarian cancer progression and activates Src gene and RhoA/ROCK pathway. A Phase images showing typical morphology of SK-OV-3 cells cultured on soft and stiff collagen I coated PA gels. Scale bar: 50 μm. B Cell surface areas calculated by digital image analysis of phase-contrast images of cells on soft and stiff collagen I coated PA gels (**P < 0.01). C Representative immunofluorescence images of SK-OV-3 cells (left) and quantifications (right) for phalloidin (red) and with DAPI (blue) (*P < 0.05). Scale bar: 20 μm. D Migratory tracks of SK-OV-3 cells cultured on soft or stiff substrates. E Migratory (left) and invasive (right) ability of SK-OV-3 cells cultured on soft versus stiff substrates evaluated by transwell assays (*P < 0.05). F The proliferation of SK-OV-3 cells cultured on soft versus stiff substrates was measured by EdU assay, DAPI (blue). Scale bar: 50 μm. (right) Quantification of EdU-positive nuclei from n = 3 experiments (**P < 0.01). G Young’s modulus of tumors from mice treated with saline or BAPN (n = 8 each group) were assessed by AFM (***P < 0.001). H Representative bioluminescence images of mice (n = 8 each group) treated with saline or BAPN for 4 weeks after tumor implantation. Bar graph showing the quantification of normalized total photon counts in each group (n = 8 each group, **P < 0.01). I Incidence of metastases was decreased by BAPN treatment. In saline-treated group, seven mice have peritoneal metastasis, the incidence of metastasis was 87.5 %; in BAPN-treated mice, only one mouse has peritoneal metastasis, the incidence of metastasis was 12.5 % (n = 8). J-K Representative macroscopic images (J) of SK-OV-3-ip3-luc orthotopic xenograft treated with saline or BAPN. K Tumors from each group were resected and counted. L Western blot from cell lysates of SK-OV-3 cells showing expression of p-Src (Try416), Src and GAPDH. GAPDH was used as a loading control. M Western blot from cell lysates of SK-OV-3 cells on soft and stiff substrates showing expression of, RhoA, ROCK1, ROCK2 and GAPDH. GAPDH was used as a loading control. Activated-RhoA was detected by RhoA pull down analysis