Figure 3
IGFBP7 expression is up- and Latexin expression is downregulated in the xenograft melanoma induced by CEACAM1 kd cells. (A) IGFBP7 and Latexin expression are significantly regulated on the transcriptional level as determined by qRT-PCR with template cDNA derived from RNA from MeWo tumors (human melanoma cell line) subcutaneously grown in scid mice. Please note that lower Cp values mean higher levels of expression: IGFBP7 expression is significantly higher in MeWo CEACAM1 kd than in MeWo Luc control tumors whereas latexin expression is significantly lower in the MeWo CEACAM1 kd tumors. Each experiment was performed twice with 5 replicates each time. (B) Immunohistochemical staining of paraffin embedded tumor tissue (xenograft MeWo tumors in scid mice) for IGFBP7 and latexin demonstrated respective up- and downregulation of these two proteins. Little to no IGFBP7 (in red) could be shown in the MeWo Luc tumors (upper left panel) whereas high IGFBP7 was detected in the MeWo CEACAM1 kd tumors (lower left panel). Vice versa, high latexin expression could be detected in the MeWo Luc tumors (upper right panel) and little to no latexin expression in the CEACAM1 kd tumors (lower right panel). (C) IGFBP7 and latexin expression are up- and downregulated, respectively, on the cell culture level in MeWo CEACAM1 kd cells compared with MeWo Luc cells: Flow cytometric determination of intracellular IGFBP7 and latexin in MeWo Luc (teal curves) and MeWo CEACAM1 kd cells (orange curves) with corresponding isotype controls (black curves).
