Cell differentiation dependent expressed CCR6 mediates ERK-1/2, SAPK/JNK, and Akt signaling resulting in proliferation and migration of colorectal cancer cells.
The expression of CCL20 (MIP-3alpha), which chemoattracts leukocytes to sites of inflammation, has been shown in intestinal epithelial cells (IEC). Aim of this study was to analyze the role of the CCL20 receptor CCR6 in IEC and colorectal cancer (CRC) cells. Expression of CCR6 and CCL20 was analyzed by RT-PCR and immunohistochemistry. Signaling was investigated by Western blotting, proliferation by MTS assays and chemotactic cell migration by wounding assays. The effect of CCL20 on Fas-induced apoptosis was determined by flow cytometry. CCR6 and its ligand CCL20 are expressed in IEC. Moreover, CRC and CRC metastases express CCR6, which is upregulated during IEC differentiation. Stimulation of IEC with CCL20 and proinflammatory stimuli (TNF-alpha, IL-1beta, LPS) significantly upregulates CCL20 mRNA expression. CCL20 expression was significantly increased in inflamed colonic lesions in Crohn's disease and correlated significantly with the IL-8 mRNA expression in these lesions (r = 0.71) but was downregulated in CRC metastases. CCL20 activated Akt, ERK-1/2, and SAPK/JNK MAP kinases and increased IL-8 protein expression. The CCL20 mediated activation of these pathways resulted in a 2.6-fold increase of cell migration (P = 0.001) and in a significant increase of cell proliferation (P < 0.05) but did not influence Fas-induced apoptosis. In conclusion, IEC and CRC express CCL20 and its receptor CCR6. CCL20 expression is increased in intestinal inflammation, while CCR6 is upregulated during cell differentiation. CCR6 mediated signals result in increased IEC migration and proliferation suggesting an important role in intestinal homeostasis and intestinal inflammation by mediating chemotaxis of IEC but also in mediating migration of CRC cells.
Brand
Stephan
S
Department of Medicine II, University-Hospital Munich-Grosshadern, University of Munich, Munich, Germany. stephan.brand@med.uni-muenchen.de
Olszak
Torsten
T
Beigel
Florian
F
Diebold
Joachim
J
Otte
Jan-Michel
JM
Eichhorst
Soeren T
ST
Göke
Burkhard
B
Dambacher
Julia
J
D018938:Caco-2 Cells; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D054418:Chemokine CCL20; D019742:Chemokines, CC / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism*; D003424:Crohn Disease / Q000378:metabolism; D016207:Cytokines / Q000502:physiology; D053222:Fas Ligand Protein; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000502:physiology; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D019402:Macrophage Inflammatory Proteins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D054399:Receptors, CCR6; D019707:Receptors, Chemokine / Q000378:metabolism*; D015398:Signal Transduction; D048069:Tumor Necrosis Factors / Q000378:metabolism
C108355:CCL20 protein, human; C106311:CCR6 protein, human; D054418:Chemokine CCL20; D019742:Chemokines, CC; D016207:Cytokines; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D016209:Interleukin-8; D019402:Macrophage Inflammatory Proteins; D008562:Membrane Glycoproteins; D054399:Receptors, CCR6; D019707:Receptors, Chemokine; D048069:Tumor Necrosis Factors; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048369:MAP Kinase Kinase 1; D048670:MAP Kinase Kinase 4; C482125:MAP2K1 protein, human