alpha V beta 6 integrin promotes invasion of squamous carcinoma cells through up-regulation of matrix metalloproteinase-9

The integrin alphav beta6 is a fibronectin receptor, which is not detectabl e on normal epithelium but is neo-expressed in oral epithelial dysplasia an d oral squamous-cell carcinoma (SCC), suggesting a role in promoting malign ant behaviour and tumour progression. We used transfection and retroviral i nfection to create a panel of SCC cell lines expressing various levels of a lphav beta6 to examine this possibility. We found that increased expression of alphav beta6 in malignant keratinocytes upregulates MMP-9 and MMP-2 exp ression and promotes invasion in an MMP-9-dependent manner, Our results sug gest a possible mechanism for the involvement of alphav beta6 in squamous c arcinoma in vivo. (C) 2001 Wiley-Liss, Inc.