Overexpression of macrophage inflammatory protein-3α in oral cavity squamous cell carcinoma is associated with nodal metastasis.

We examined the role of macrophage inflammatory protein (MIP)-3α on oral cavity squamous cell carcinoma (OSCC) and whether it was involved in modulating OSCC cell functions. The study population was comprised of 102 patients with OSCC. MIP-3α levels in tissues were examined by immunohistochemistry and quantitative real-time RT-PCR. Effects of MIP-3α on OSCC cell function were investigated by cell proliferation assays, trans-well migration/invasion assays, and RNA interference. We found that MIP-3α was overexpressed in OSCC tumor cells. MIP-3α expression was significantly higher in tumor cells vs. normal epithelial cells, as determined by both quantitative real-time RT-PCR and immunohistochemistry. Overexpression of MIP-3α was significantly correlated with positive pN status (P=0.036). Nevertheless, there were no correlations related to patient age, pT status, overall pathological stage, cell differentiation, or perineural invasion. The long-term disease-specific survival for patient subgroups stratified by the absence or presence of MIP-3α overexpression was 70.9% vs. 54.7% (P=0.041). Multivariate analysis indicated that MIP-3α overexpression had a significantly lower disease-specific survival (hazard ratio: 2.158; P=0.037). Additionally, in vitro suppression of MIP-3α expression in OECM-1 cells using specific interfering RNAs attenuated cell migration and invasiveness. These findings suggest that MIP-3α overexpression in OSCC is associated with a poorer prognosis for patient survival and contributes to tumor metastasis.