MicroRNA-150 inhibits tumor invasion and metastasis by targeting the chemokine receptor CCR6 in advanced cutaneous T-cell lymphoma
Menée à l'aide de modèles murins, cette étude met en évidence des mécanismes par lesquels, en régulant l'expression du récepteur CCR6, le micro-ARN 150 inhibe les processus invasif et métastatique d'un lymphome T cutané
We show here that microRNA (miR)-150 is significantly downregulated in advanced cutaneous T-cell lymphoma (CTCL), and that this downregulation is strongly associated with tumor invasion/metastasis. Inoculation of CTCL cell lines into NOD/Shi-scid IL-2γnul mice led to CTCL cell migration to multiple organs; however, prior transfection of the cells with miR-150 substantially reduced the invasion/metastasis by directly downregulating CCR6, a specific receptor for the chemokine CCL20. We also found that IL-22 and its specific receptor subunit, IL22RA1, were aberrantly overexpressed in advanced CTCL, and that production of IL-22 and CCL20 was increased in cultured CTCL cells. IL22RA1 knockdown specifically reduced CCL20 production in CTCL cells, suggesting IL-22 upregulation may activate production of CCL20 and its binding to CCR6, thereby enhancing the multidirectional migration potential of CTCL cells. CTCL cells also exhibited nutrition- and CCL20-dependent chemotaxis, which were inhibited by miR-150 transfection or CCR6 knockdown. From these findings we conclude that, in the presence of continuous CCR6 upregulation accompanied by miR-150 downregulation, IL-22 activation leads to continuous CCL20-CCR6 interaction in CTCL cells and, in turn, autocrine metastasis to distal organs. This suggests miR-150, CCL20, and CCR6 could be key targets for the treatment of advanced CTCL.