Metastatic cancer stem cells--quo vadis?

On the basis of the observation that the chemokine stromal-derived factor 1 (SDF-1) is produced at high concentrations in classic metastatic sites in pancreatic cancer such as the liver, bone, and lung, we found that a subpopulation of CD133+ cells that express the SDF-1 receptor CXCR4 ( C-X-C chemokine receptor type 4) could be tracked in portal vein blood and that this cell subpopulation drove metastasis exclusively. First steps have already been taken, and circulating tumor cells have been isolated from the peripheral blood of cancer patients.