?v?6 integrin promotes invasion of squamous carcinoma cells through up-regulation of matrix metalloproteinase-9

Abstract

The integrin ?V?6 is a fibronectin receptor, which is not detectable on normal epithelium but is neo-expressed in oral epithelial dysplasia and oral squamous-cell carcinoma (SCC), suggesting a role in promoting malignant behaviour and tumour progression. We used transfection and retroviral infection to create a panel of SCC cell lines expressing various levels of ?V?6 to examine this possibility. We found that increased expression of ?V?6 in malignant keratinocytes up-regulates MMP-9 and MMP-2 expression and promotes invasion in an MMP-9-dependent manner. Our results suggest a possible mechanism for the involvement of ?V?6 in squamous carcinoma in vivo