BackgroundMatrix metalloproteinase 7 (MMP7), as the smallest member of the matrix metalloproteinase family, has been verified to be implicated in cancer progression, especially metastasis. However, its expression pattern and function in tongue cancer is not clear.MethodsThe expression of MMP7 in human tongue squamous cell carcinoma (TSCC) specimens compared with their respective paired nontumour tissues by real-time PCR and immunohistochemical staining. The effect of MMP7 on the proliferation, apoptosis, migration, invasion of tongue cancer cells was tested in appropriate ways after MMP7 siRNA knockdown or overexpression. The effect of MMP7 on lymph node metastasis in vivo was analyzed using a high-metastasis orthotopic nude mouse tongue transplanted tumour model.ResultsWe found markedly elevated expression of MMP7 in human TSCC specimens compared with their respective paired nontumour tissues, and this high expression was correlated with the patients’ lymph node metastasis. Furthermore, the results of molecular functional assays confirmed that MMP7 promotes cell proliferation, migration and invasion of TSCC cells. Knockdown of MMP7 inhibited lymph nodes metastasis in vivo.ConclusionsMMP7 plays an oncogenic role in carcinogenesis and metastasis of tongue cancer, and may serve as a potential therapeutic target for tongue cancer.