Virtual Screening-Guided Discovery of Small-Molecule CHI3L1 Inhibitors with Functional Activity in Glioblastoma Spheroids.

Overview

Chitinase-3-like protein 1 (CHI3L1), a glycoprotein implicated in inflammation and cancer, has emerged as a therapeutic target for glioblastoma (GBM). CHI3L1 contributes to tumor progression and immune evasion by promoting STAT3 signaling and mesenchymal transition. To identify small-molecule CHI3L1 inhibitors, a structure-based 3D pharmacophore model was developed and applied to virtually screen over 4.4 million compounds. We selected 35 candidates for experimental evaluation. Binding validation via MST confirmed dose-dependent CHI3L1 interactions for two compounds, 8 and 39, with dissociation constants (K _d) of 6.8 μM and 22 μM, respectively. These CHI3L1 affinities were further supported by SPR-based screening. In 3D GBM spheroid models, compound 8 reduced spheroid viability and attenuated phospho-STAT3 levels, consistent with CHI3L1 pathway disruption. Compared to the previously reported CHI3L1 inhibitors, compound 8 demonstrates superior CNS pharmacokinetics, inhibition of STAT3 and angiogenesis, and enhanced efficacy in GBM spheroids, establishing it as a more translationally viable scaffold.