The CCL5/CCR5 axis contributes to the perineural invasion of human salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma (SACC) has a unique tendency for perineural invasion (PNI), which results in tumor recurrence and poor prognosis. Recent studies have shown that the chemokine CCL5 and its receptor CCR5 play important roles in tumor invasion and metastasis. However, the role of the CCL5/CCR5 axis in the PNI of SACC has not been studied to date. In the present study, we evaluated the expression of CCL5 and CCR5 in SACC cases and nerve tissues, and performed a series of in vitro assays with the SACC cell line, SACC-83, to indicate the role of the CCL5/CCR5 axis in the PNI of SACC. We found that CCL5 (35.9%; 23/64) and CCR5 (70.3%; 45/64) were positively expressed in SACC cases, and the expression of CCR5 was significantly associated with the PNI of SACC (P<0.05). We also found that SACC-83 cells expressed the functional receptor, CCR5, for the chemokine CCL5, as demonstrated by calcium mobilization and actin polymerization assays. Furthermore, we found that exogenous CCL5 significantly facilitated the migration, invasion and PNI activity of SACC-83 cells in vitro (P<0.05). Further study showed that the CCR5 inhibitor (maraviroc) effectively blocked the migration, invasion and PNI activity of SACC-83 cells with or without CCL5 stimulation (P<0.05). These results indicate that the CCL5/CCR5 axis plays a critical role in the PNI of SACC, and that antagonists against CCR5 may be an effective anti-PNI agent for SACC therapy.