Figure 4

DU145-LN sublines exhibit increased migration and invasion with metastatic ability, relative to DU145 cells. DU145-LN metastatic sublines show increased (A) cell migration in the transwell migration assay and (B) increased invasion in the Matrigel invasion assay. For both assays: Mean of triplicate assays ± S.D. Student t-test, *p < 0.05, **p < 0.01, (C) IHC of orthotopic prostate tumors with K18 (brown) and counterstained with hematoxylin (blue). Margins were smooth and well-defined in the DU145 tumors (top left panel), while invasive margins were observed in DU145-LN1 (top right panel) and DU145-LN3 (lower left panel) tumors. Right lower panel shows magnified image of DU145-LN4 tumor seen in Figure 2A. Double staining of K18 (brown) and podoplanin (black) shows tumor foci present in an enlarged lymphatic vessel and in a tumor-associated blood vessel (arrows) (lower right panel). Scale bars = 100 μm.