Figure 2From: Podocalyxin enhances breast tumor growth and metastasis and is a target for monoclonal antibody therapy Podocalyxin promotes primary tumor formation, local invasion and metastasis. (A) Growth curve of subcutaneous (s.c.) flank tumors initiated in NSG mice by scrambled shRNA control (shCTRLRFP; closed squares) or shRNA targeting PODXL (shPODXLRFP; open circles) MDA-MB-231 cells (left; n = 5 for shCTRLRFP group and n = 6 for shPODXLRFP group; growth curves are significantly different with P < 0.001). Similarly, we compared s.c. tumor growth of shCTRLGFP with shPODXLGFP MDA-MB-231 cells in NSG mice (right; n = 6; growth curves are significantly different with P < 0.05). GFP, Green fluorescent protein; RFP, Red fluorescent protein. The final volume of the excised tumors was measured on the dates mice were killed (left; day 21, right; day 20). (B) Wet weight (g) of pooled shCTRL (solid bar) and shPODXL (open bar) tumors weighed immediately after excision (n = 11 for shCTRL group and n = 5 for shPODXL group; *P < 0.05). Representative photograph of excised shCTRL and shPODXL tumors (inset). (C) Representative H&E–stained images of shCTRL (upper left) and shPODXL (upper right) primary tumor sections (scale bar = 1 mm). Representative immunofluorescence images of shCTRL (lower left) and shPODXL (lower right) primary tumor sections showing Ki-67-positive cells (green). DAPI stain was used as a nuclear marker (blue). (D) The number of tumor cells detected in the lungs 20 or 21 days after subcutaneous injection. Data shown are the number of fluorescent tumor cells (×103) per 106 events detected by flow cytometry (n = 11 for shCTRL group and n = 5 for shPODXL group; *P < 0.05). The data shown are representative of three independent experiments.Back to article page