Expression of collagenase-3 (matrix metalloproteinase-13) in squamous cell carcinomas of the head and neck

Squamous cell carcinomas (SCCs) of the head and neck are malignant tumors with high capacity to invade and metastasize. We have examined expression of the new collagenase, collagenase-3 (MMP-13), in SCCs of the head and neck. MMP-13 mRNAs were detected in 22 of 29 SCC cell lines: in 14 of 15 primary SCC cell lines and in 8 of 14 SCC cell lines from recurrent tumors or metastases. MMP-13 mRNAs were expressed by all 6 cell lines from highly invasive primary tumors and in all 4 cell lines from small aggressive tumors. Using in situ hybridization, MMP-13 mRNAs were detected in 15 of 17 SCC tumor samples. In most tumors, MMP-13 was expressed by tumor cells at the invading front of the tumors, but in a subset of SCCs, MMP-13 mRNA was also expressed by stromal fibroblasts. No MMP-13 expression was detected in intact skin or oral mucosa. MMP-13 mRNA levels in SCC cells were enhanced by transforming growth factor-beta, tumor necrosis factor-alpha, transforming growth factor-alpha, and keratinocyte growth factor. Specific expression of MMP-13 by SCC cells in vitro and in vivo strongly suggests a role for MMP-13 in the high invasion capacity of SCC cells.