TY - JOUR AB - Integrins are a family of transmembrane adhesion receptors that might transduce signals from the extracellular matrix into the inside of cells after ligand binding. In order to investigate whether β3 integrins expressed in tumor cells might mediate such outside-in signaling, human MDA-MB-231 breast cancer cells that were stably transfected with either β3 integrin or mock-transfected were investigated in a matrigel degradation assay and a grafting experiment was performed on the developing chicken chorioallantoic membrane (CAM). After cultivation on matrigel for time periods between one and five days, more matrigel was digested in the wells in which β3 integrin expressing cells were incubated than in wells of mock-transfected cells. Furthermore, extracts of β3 integrin expressing cells contained higher levels of MMP-2 protein as determined by immunoblotting and more MMP-2 associated gelatinase activity as detected by zymography than extracts of mock-transfected cells. Matrigel degradation and gelatinase activity as well as MMP-2 expression were elevated when β3 integrin expressing cells were incubated in the presence of the RGD peptide (mimicking an integrin ligand). After grafting on 10 day-old embryonic chicken CAM for three to five days, β3 integrin expressing cells assembled in spheroids showed higher rates of spreading on the CAM surface and CAM invasion as well as a significant MMP-2 up-regulation compared to mock-transfected cells. The results from the in vivo and in vitro experiments allow the conclusion that the presence of β3 integrin in MDA-MB-231 breast cancer cells induced an increased MMP-2 expression and activity that might contribute to the enhanced invasive potential observed. AD - Institute of Anatomy, University of Bern, Switzerland null AU - Baum,Oliver AU - Hlushchuk,Ruslan AU - Forster,Andrea AU - Greiner,Richard AU - Clézardin,Philipp AU - Zhao,Yingshe AU - Djonov,Valentin AU - Gruber,Günther DA - 2007/02/01 DO - 10.3892/ijo.30.2.325 EP - 332 IS - 2 JO - Int J Oncol PY - 2007 SN - 1019-6439 1791-2423 SP - 325 ST - Increased invasive potential and up-regulation of MMP-2 in MDA-MB-231 breast cancer cells expressing the β3 integrin subunit T2 - International Journal of Oncology TI - Increased invasive potential and up-regulation of MMP-2 in MDA-MB-231 breast cancer cells expressing the β3 integrin subunit UR - https://doi.org/10.3892/ijo.30.2.325 VL - 30 ER -