gms | German Medical Science

Einleitung: Various chemokine receptors namely CXCR4, CCR6 and CCR7 have recently been shown to be involved in the regulation of metastasis in malignant tumors. However, little is known about the role of these receptors in promoting tumor metastasis of colorectal cancer to the primary site of colorectal cancer metastasis in the liver. To investigate this issue, we analysed the expression of the chemokine receptors CXCR4, CCR6 and CCR7 in colorectal tumors and colorectal liver metastases.

Material und Methoden: In the present study, 30 human cancer samples from colorectal tissue, 30 human samples from colorectal liver metastases and the adjacent non-tumorous liver tissues along with 10 non-tumorous tissue samples from stomach, oesophagus, pancreas, colon and rectum, respectively, were screened using quantitative real-time PCR (Q-RT-PCR), enzyme-linked immunosorbent assay (ELISA), Western blot analysis, Histochemistry (HC), Microdissection and Immunohistochemistry (IHC).

Ergebnisse: Among the chemokine receptors CXCR4, CCR6 and CCR7 only CCR6 was significantly overexpressed in both malignant colorectal tumors and colorectal liver metastases. Consequently, we investigated the expression of the corresponding CCR6 receptor ligand CCL20/MIP3α in different organs such as stomach, oesophagus, pancreas, colon and rectum in comparison to their expression in the liver as the most common metastatic destination of colorectal cancer. Compared with these organs we found that CCL20 exhibits peak levels of expression in the liver.

Schlussfolgerung: Our results indicate that an increased production of CCL20 may contribute to the selective recruitment of CCR6- expressing colorectal cancer cells to the liver. Therefore, our findings strongly indicate an association between CCL20/CCR6 expression in human colorectal cancer and the promotion of colorectal liver metastasis.