DC-SIGN-LEF1/TCF1-miR-185 feedback loop promotes colorectal cancer invasion and metastasis.

ABSTRACT

DC-SIGN is previously focused on its physiologic and pathophysiologic roles in immune cells. Little is known about whether DC-SIGN is expressed in malignant epithelial cells and how DC-SIGN participates in tumor progression. Here we showed that DC-SIGN expression was increased in metastatic colorectal cancer (CRC) cell lines and patient tissues. The overall survival in CRC patients with positive DC-SIGN was remarkably reduced. Gain of DC-SIGN function facilitated the CRC metastases both in vitro and in vivo, and this effect was reversed by miR-185. DC-SIGN and Lyn interacted physically, and Lyn maintained the stability of DC-SIGN in cells. DC-SIGN activation recruited Lyn and p85 to form the DC-SIGN-Lyn-p85 complex, which promoted CRC metastasis by increasing PI3K/Akt/ß-catenin signaling in tyrosine kinase Lyn-dependent manner. Furthermore, activation of DC-SIGN promoted the transcription of MMP-9 and VEGF by increasing PI3K/Akt/ß-catenin signaling, and induced TCF1/LEF1-mediated suppression of miR-185. Our findings reveal the presence of the DC-SIGN-TCF1/LEF1-miR-185 loop in cancer cells with metastatic traits, implying that it may represent a new pathogenic mechanism of CRC metastasis. This character of the loop promises to provide new targets for blocking CRC invasive and metastatic activity.