Toward understanding recurrent meningioma: the potential role of lysosomal cysteine proteases and their inhibitors

Abstract

The data indicate that the cysteine cathepsins and their inhibitors are involved in a process related to early meningioma recurrence, regardless of their histological classification. Of note, the known tumor invasiveness marker cathepsin B, measured in whole-tumor homogenates, was not prognostic, in contrast to its endogenous inhibitor stefin B, which was highly significant and the only independent prognostic factor to predict meningioma relapse in multivariate analysis and reported herein for the first time. Stefin B inhibition of local invasion was confirmed by in vitro invasion assay, although its other functions cannot be excluded.