[The role of plasma chemokines in cancer]

Chemokines have diverse roles in tumor biology. Monocyte chemotactic protein-(MCP-1)/CCL2 was the first chemokine described to elicit influx of monocyte/macrophages into tumors. Application of chemokines as anti-tumoral therapy to attract immunocompetent cells and to mediate the mounting of an efficient anti-tumoral response has been tested as a method to combat cancer for some years now. However, these chemokine-related therapy has not yet been approved for clinical application, although it has been tested succesfully in animal models for years now. A different kind of approach for chemokine anti-cancer therapy involves angiostatic chemokines. These chemokines inhibit pro-angiogenic tumoral factors, thereby limiting tumor growth and metastasis. Recently, we described a most potent new angiostatic chemokine, namely a variant of platelet factor 4, designated PF-4var/CXCL4L1. With regard to hematological tumors we described a new plasma chemokine, PARC/CCL18, that can be used to distinguish between pediatric patients with acute lymfoid leukemia or acute myeloid leukemia. Whether this elevated plasma concentration of PARC/CCL18 is the cause of the pathology or the consequence of a disturbed cytokine balance is not clear at the moment.