Matrix metalloproteases (MMPs) are endopeptidases involved in tumor cell invasion. Childhood acute lymphoblastic leukemia (ALL) is characterized by its capacity to infiltrate different organs. We analyzed the expression of MMP-2, -9, -14 and TIMP-1 and -2 in a prospective study on 86 children with newly diagnosed ALL (73 B- and 13 T-lineage) and 9 children at relapse with B-ALL. Membrane-bound and intracytoplasmic MMPs and TIMPs were analyzed by flow cytometry, and secreted MMPs were quantified by ELISA. In patients at relapse, MMP-14 was present in a greater proportion of the B-ALL cell population than at diagnosis. In patients with peripheral infiltration, intracytoplasmic MMP-9 was significantly higher than in patients without infiltration. ROC curve and Kaplan-Meier curve analysis showed that a high secretion of MMP-9 (>2450 pg/ml/10(6) cells) was associated with a lower overall survival rate, suggesting that the secretion of MMP-9 is an independent prognostic factor in childhood B-ALL.
2009 Elsevier Ltd. All rights reserved.