OBJECTIVETo investigate the expression of chemokine receptor CXCR4 and its ligand CXCL12 in oral squamous cell carcinoma (OSCC) cells, and their effects on proliferation and migration of tumor cells.

METHODSThe expression of CXCR4 mRNA and protein in 20 cases of OSCC tissue, cervical lymph nodes, tongue cancer cell line Tca8113, buccal cancer cell line Bca885, and 10 specimens of normal oral mucosa tissue were examined by reverse transcriptase-polymerase chain reaction(RT-PCR) and Western blot. The expression of CXCL12 mRNA was examined by RT-PCR. MTT assay was used to evaluate the CXCR4/CXCL12 influence on proliferation of tumor cells. Chemotaxis and migration response to CXCR4 particular ligand-CXCL12 were detected by chemotaxis assay.

RESULTS1) Expression levels of CXCR4 mRNA and protein in OSCC tissues, Tca8113 and Bca885 cells were 2.31 +/- 1.13, 1.89 +/- 1.20, 1.67 +/- 1.10 and 1.36 +/- 0.15, 1.85 +/- 0.34, 1.97 +/- 0.23, respectively. CXCR4 mRNA and protein couldn't be detected in normal tissues. CXCL12 mRNA level in cervical lymph nodes was 1.14 +/- 0.87, CXCL12 mRNA couldn't be detected in OSCC and normal tissues. 2) In MTT assay, recombinant CXCL12 stimulated proliferation of tumor cells and CXCR4 neutralization by monoclonal antibodies decreased proliferation. 3) The chemotactic migration of OSCC cells could be induced by CXCL12. CXCL12 at a concentration between 30 ng x mL(-1) and 100 ng x mL(-1) induced the chemotactic migration of OSCC cells in a dose-dependent manner.

CONCLUSIONCXCR4/CXCL12 system may promote proliferation and migration of tumor cells, and may play an important role in lymph node metastasis of OSCC.