Down-Regulation of MT1-MMP expression by the alpha3 chain of type IV collagen inhibits bronchial tumor cell line invasion.

The basement membrane (BM) is the first barrier encountered by tumor cells when they become invasive. Moreover, some invasive tumor clusters are surrounded by a remnant or neosynthetized BM material. We have previously reported the presence of a particular alpha chain of type IV collagen, the alpha3(IV) chain, in bronchopulmonary carcinomas.