Increased Invasion and Expression of MMP-9 in Human Colorectal Cell Lines by a CD44-dependent Mechanism

Background: In order to investigate the interactions between MMPs and CD44 we stably transfected a non-invasive colon cell line, SW480 with the cDNA for MMP-9 and investigated the effect on CD44 expression and in vitro invasion and migration. Materials and Methods: In vitro invasion and migration assays were carried out using Biocoat matrigel invasion chambers. MMP and CD44 expression was determined using zymography, Western blot analysis and RTPCR. Results: Transfection of the parental SW480 cells with the cDNA for MMP-9 (SW480M9) caused increased invasion and migration. MMP-9 expression increased when the SW480M9 cells were grown on HA and collagen and cultured in the presence of a CD44-activating antibody. Treatment of the cells with H4 and a CD44-activating antibody also resulted in increased invasion, migration and attachment. Conclusion: These results demonstrated that CD44 and MMP interactions are important in controlling tumour cell invasion and migration.