Skip to main content
. Author manuscript; available in PMC: 2015 Jun 1.
Published in final edited form as: Mol Cancer Res. 2014 Mar 20;12(6):953–964. doi: 10.1158/1541-7786.MCR-13-0668

Figure 7. Hypothetical model of stress-induced, CXCR4-dependent invasion and metastasis.

Figure 7

A. Migration of CHLA-25, and TC32 cells towards SDF-1α (100ng/mL) was measured using real-time cell analysis (xCELLigence CIM-Plate 16) in normoxic (21% O2) or hypoxic conditions (1% O2). Chemotactic migration of each cell line was further increased in hypoxia relative to normoxia.

Graphs represent mean ± SEM of three independent experiments with four replicates per condition. Cell index was normalized to migration in normoxic conditions for each cell line. *, P < 0.05 as compared to controls.

B. A growing tumor begins to deplete its resources, including growth factors and oxygen. Continued tumor growth leads to space constraint at the primary site. Upregulation of CXCR4 in response to these microenvironmental stresses promotes invasion of Ewing sarcoma cells through basement membranes and extracellular matrix and chemotaxis towards SDF-1α rich secondary sites such as lung and bone marrow.