T-box transcription factor Brachyury in lung cancer cells inhibits macrophage infiltration by suppressing CCL2 and CCL4 chemokines

Both intra-tumor macrophage and T-box transcription factor Brachyury (T) have been proved to play important roles in tumor progression and metastasis. However, it is still unknown whether T could regulate the infiltration of macrophages. Here, we report that the Brachyury expression in human lung tumors was inversely correlated with the infiltration of macrophages. Brachyury suppressed the capability of human lung cancer cells to attract macrophages. Using PCR array, we found that Brachyury inhibited expression of several chemokines, including CCL2, CCL4, and CXCL10. Accordingly, knockdown of CCL2 and CCL4 in lung cancer cells suppressed macrophage invasion under coculture conditions. Furthermore, we found that Brachyury expression was inversely correlated with CCL2 and CCL4 expression in human lung tumors. Taken together, our findings shed light on the novel role of Brachyury in regulation of macrophage infiltration.