(a) Enhanced activity of miR-9-regulated reporter by infection of 4T1 cells with the miR-9 sponge. A representative experiment is shown in triplicate along with s.e.m.
(b) Primary tumor weight in Balb/c mice that received orthotopic injection of 4T1 cells infected with the miR-9 sponge or control sponge, at 4 weeks after transplantation.
(c) Bright field imaging and H&E staining of lungs isolated from mice that received orthotopic injection of 4T1 cells infected with the miR-9 sponge or control sponge, at 4 weeks after transplantation. Arrows indicate metastatic nodules. Magnification: x8 for bright field imaging; x40 for H&E staining.
(d, e) Numbers of visible lung metastases (d) and metastasis index (= number of metastases/primary tumor weight, e) in mice that received orthotopic injection of 4T1 cells infected with the miR-9 or control sponge, at 4 weeks after transplantation. Data in b, d and e are presented as mean ± s.e.m. (n = 8 mice per group).