Fig. 4

HuMETCAM/MUC18 expression in the subcutaneous tumors of SK-OV-3 clones/cells. a The expression of huMETCAM/MUC18 in the lysates from the tumors was determined by Western blot analysis as described in “Methods”. Lysates from SK-Mel-28 cells (lane 1) and from LNCaP cells (lane 2) were used as the positive control and the negative control, respectively. The huMETCAM/MUC18 expression levels in the tissue cultured cells of two SK-OV-3 clones, METCAM clone 2D and the control (vector) clones 3D, are shown (lanes 3–4) in comparison with those in the tumor lysates (lanes 5–16). The huMETCAM/MUC18 expression levels in the combined lysate from the two dorsal tumors (DSC) of the METCAM clone 2D (#421-422), the lysate of each of the five dorsal tumors (DSC) from the control (vector) clone 3D (#428-432), the combined lysate from two ventral tumors (VSC) from the METCAM clone 2D (#423-424), and the lysate of each of the five ventral tumors (VSC) from the control (vector) clone 3D (#433-437) are shown. As loading controls, the same membranes were reacted with antibodies against three house-keeping genes, but only actin and GAPDH are shown. b Histology and immunohistochemistry (IHC) of SC tumors of the two SK-OV-3 clones. Panels a–d show histology of the tumor sections from the two SK-OV-3 clones injected at dorsal (DSC) or ventral (VSC) subcutaneous sites. Panels e to l show the IHC of these tumor sections. A tissue section of SC tumors derived from the human prostate cancer LNCaP-expressing clone (LNS239) was used as a positive external control for IHC staining (data not shown). IHC of all tumor sections were carried out as previously described in “Methods”. Panels e to h show the anti-huMETCAM/MUC18 antibody staining of the cells in the tumor sections. Both tumor sections (DSC and VSC) from the METCAM clone 2D showed strong brown color staining in IHC when the antibody was added (Panels e & f), however, the two tumor sections (DSC and VSC) from the control (vector) clone 3D showed a weak background staining (Panels g & h). Panels i to l show the corresponding negative controls which show no staining in the adjacent sections when no antibody or when the control chicken IgY was added