Engineered N-TIMP2 Variant Specifically Targeting MMP-9 Exhibits Potent Anti-Glioblastoma Activity.

Glioblastoma (GB) is the most aggressive form of brain cancer. However, despite intensive intervention, GB almost invariably recurs due to the highly invasive nature of its tumor cells, which infiltrate surrounding healthy brain tissue, underscoring the urgent need for more effective therapies. One such approach could be based on targeting matrix metalloproteinase-9 (MMP-9), an enzyme that plays a crucial role in GB progression and is closely associated with enhanced invasiveness and poor prognosis. Previously, we engineered a potent and selective MMP-9 inhibitor derived from the N-terminal domain of the endogenous tissue inhibitor of metalloproteinases-2 (N-TIMP2). In this study, we evaluate the efficacy and toxicity of this engineered N-TIMP2 variant (REY) in adult GB U251 and normal Vero cells using multiple in vitro assays. Our results demonstrate that REY significantly inhibits colony formation and cell invasion, and markedly reduces spheroid spreading at nanomolar concentrations. Importantly, the engineered variant, which is highly specific for MMP-9, consistently outperforms the wild-type N-TIMP2, which broadly targets multiple MMPs, and exhibits no cytotoxicity toward healthy cells. Together, these findings support MMP-9 as a viable therapeutic target in GB and highlight the potential of our engineered N-TIMP2 variant as a promising candidate for further therapeutic development.