Figure 3. Attachment of OvCa cells depends on MMP-2.

(A) SKOV3ip1 cells were transfected with a siRNA specific for MMP-2, MMP-9, or a control siRNA and plated on collagen type I, and MMP-2 and MMP-9 were detected by immunoblotting with specific antibodies. The membrane was reprobed with actin. (B–D) Adhesion assays. SKOV3ip1 cells were transfected with a siRNA specific for MMP-2 and MMP-9. SKOV3ip1, HeyA8, and primary OvCa cells were pretreated with an MMP-2– or MMP-9–blocking antibody and then fluorescently labeled. OvCa cells were added to the 3D culture (B), a piece of full human omentum (C), or full human peritoneum (D), and the adherent cells quantified with a fluorescence reader as described in Figure 2. (E) SKOV3ip1 cells (1 × 10⁶) were labeled fluorescently and injected i.p. into nude mice for 4 hours (n = 3). Mice were sacrificed after 4 hours, omentum and peritoneum was lysed with NP-40, and fluorescence was measured. (F) Adhesion assay. SKOV3ip1 cells (5 × 10⁴) pretreated with the MT1-MMP antibody were added to the 3D culture and an adhesion assay performed as described in Figure 2 (left panel). Invasion assay (right panel). SKOV3ip1 cells (3 × 10⁴) were treated with a MT1-MMP– or MMP-9–blocking antibody, and invasion was analyzed after 24 hours. *P < 0.01.