Dual role of CCL3/CCR1 in oral squamous cell carcinoma: Implications in tumor metastasis and local host defense

Chemokines are small chemotactic cytokines that can induce the migration of leukocytes, activate inflammatory/immune responses and have recently been implicated in the regulation of tumor growth and organ-specific spread. In this setting, the macrophage inflammatory protein-la (CCL3) chemokine displays a diversity of roles that may contribute to the directional migration of squamous cells into cervical lymph nodes or to the defense against tumor initiation and progression. Thus, the aim of this study was to determine, for the first time, the expression of CCL3 and their receptors, CCR1 and CCR5, by real-time polymerase chain reaction in samples obtained from oral squamous cell carcinoma (OSCC) and healthy gingival tissue (control). In addition, we investigated the immunoexpression of these molecules in neoplastic cells (parenchyma), inflammatory/immune cells (stroma) in primary OSCC and in metastatic and non-metastatic lymph node tissues. The relationship of CCL3/CCR1 with survival data was also evaluated. The analysis of mRNA expression revealed a significantly higher expression of CCL3 and CCR1 in OSCC compared with the controls (P 0.05). However, we observed the density of CCL3 + nodal cells to be significantly higher in metastatic lymph nodes when compared with non-metastatic lymph nodes in the same patients (P