Figure 1From: Fibroblast growth factor receptor splice variants are stable markers of oncogenic transforming growth factor β1 signaling in metastatic breast cancersSpontaneously metastatic breast cancer cells dynamically regulate epithelial cadherin during in vivo primary and metastatic tumor growth. (A) Bioluminescence imaging (BLI) of metastatic 4T1 cells expressing cytomegalovirus (CMV)-driven Renilla luciferase and firefly luciferase driven by the epithelial cadherin (E-cad) promoter. Cells were engrafted onto the mammary fat pads of BALB/c mice, and qualitative E-cad promoter activity (for example, luciferin-derived bioluminescence) was monitored in vivo and ex vivo. E-cad bioluminescence was spatially correlated with E-cad protein expression as determined by IHC. Bars indicate 40x, 100x and 400x magnifications. (B) E-cad promoter activity (for example, luciferin-derived bioluminescence) was quantified by normalization to CMV promoter activity (for example, coelenterazine-derived bioluminescence) in in vitro cultured cells and ex vivo tissues derived from primary tumors and their late-stage metastases (Mets). Data represent ten samples (n = 10, ±SE) derived from five individual mice bearing primary and metastatic tumors, resulting in the indicated P values. (C) Circulating tumor cells (CTCs) were isolated from the blood of 4T1 tumor-bearing mice and selected for resistance to Zeocin. Photomicrographs show the antibiotic-resistant CTCs (CTC ex vivo). The morphologically epithelial cells (black arrow) were physically isolated from the mesenchymal cells (white arrow) and further subcultured as separate populations of mesenchymal-like and epithelial-like cells as indicated. Bars indicate a 100x magnification.Back to article page