Annexin A2 promotes glioma cell invasion and tumor progression

Abstract

Gliomas are highly invasive, lethal brain tumors. Tumor-associated proteases play an important role in glioma progression. Annexin A2 is over expressed in many cancers and correlate swith increased plasm in activity on the tumor cell surface, which mediates degradation of extracellular matrix and promotes neoangiogenesis to facilitate tumor growth. In this study, we used two glioma cell lines, mouse GL261-EGFP and rat C6/LacZ, as well as stable clones transfected with an annexinA2 knockdown construct. We find that the annexin A2 knockdown decreased glioma cell migration in vitro and decreased membrane-bound plasmin activity. In vivo, we injected the glioma cells into the rodent brain and followed glioma progression. Knockdown of annexin A2 in glioma cells decreased tumor size and slowed tumorprogression, asevidenced by decreased invasion, angiogenesis, and proliferation, as well as increased a poptosisin the tumort issue of the annexin A2knockdown group. Moreover, we report that the levels of expression ofannexinA2 in human glioma samples correlate with their degree of malignancy. Together, our findings demonstrate that inhibition of annexin A2 expression in glioma cells could become a new target for glioma therapy.