The expression of CCL20, that chemoattracts leukocytes to sites of inflammation, has been shown in breast epithelial cells. The trafficking of leukocytes, regulated by chemokines and their receptors, shares many similarities with the migration of metastatic cells. The metastatic and invasive potential of many cancers also depends on the expression of metalloproteinases (MMPs) and MMP-2 and -9 over expression and activities associated with the invasive potential of human tumours.

Aim of this study was to evaluate the expression and the functional role of CCL20 and its single receptor (CCR6) in primary cultured epithelial breast cancer cells.

Expression of CCR6, CCL20 and metalloproteinase (MMP) mRNAs was analyzed by RT-PCR; activation of signal transduction kinases Akt, ERK-1/2, and JNK was investigated by Western blotting; cell migration was assessed by culture wounding assay; activities of gelatinase MMP-2 and -9 were quantified by gelatin zymography.

mRNAs of CCR6 and its ligand CCL20 are expressed in cultured breast cancer cells. Stimulation of cells with CCL20 activated Akt, ERK-1/2, and SAPK/JNK kinases and increased MMP-2 and -9 mRNA and protein expressions and activities. The CCL20-mediated activation of the aforementioned pathways resulted in a 2.6-fold increase of cell migration. In addition, we demonstrated that MMPs inhibition signi?cantly (P < 0.05) decreased the CCL20-stimulated cell migration.

These results suggest a biological and clinical relevance of CCL20; the expression of CCR6 receptor and its CCL20 ligand within primary tumor tissue may indicate a potential role of this chemokine-receptor axis in breast cancer progression.