Matrix metalloproteinase-2 cleavage of the ?1 integrin ectodomain facilitates colon cancer cell motility.

ABSTRACT: Cancer cell invasion is a key element in metastasis that requires integrins for adhesion/de-adhesion, as well as matrix metalloproteinases (MMPs) for focalized proteolysis. Herein we show that MMP-2 is up-regulated in resected colorectal tumors and degrades ?1 integrins with the release of fragments containing the ?1 I-domain. The ?1 cleavage pattern is similar to that produced by digestion of ?5?1 and ?2?1 with MMP-2. Two such fragments, at 25 and 75 kDa, were identified after immunoprecipitation, with monoclonal antibody BD610468 reacting with the NH(2)-terminal I-like ectodomain followed by SDS-PAGE and microsequencing using electrospray (ISI-Q-TOF-Micromass) spectrometry. Cleavage of the ?1 integrin can be abolished by inhibition of MMP-2 activity; it can be induced by up-regulation of MMP-2 expression, as exemplified by HT29 colon cancer cells transfected with pCMV6-XL5-MMP-2. Co-immunoprecipitation studies of colon cancer cells showed that the ?1 integrin subunit is associated with MMP-2. The MMP-2-mediated shedding of the I-like domain from ?1 integrins resulted in decreased adhesion of colon cancer cells to collagen and fibronectin, thus abolishing their receptivity. Furthermore, such cells showed enhanced motility as evaluated by a "wound healing-like" assay and time-lapse microscopy, indicating their increased invasiveness. Altogether, our data demonstrate that MMP-2 amplifies the motility of colon cancer cells, not only by digesting the extracellular matrix components in the vicinity of cancer cells but also by inactivating their major ?1 integrin receptors.

SUBMITTER: Kryczka J 

PROVIDER: S-EPMC3476322 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature