Discovery of Small Molecule CHI3L1 Inhibitors by SPR-Based High-Throughput Screening
Abstract:
Chitinase-3-like 1 (CHI3L1) is a secreted glycoprotein implicated in carcinogenesis and tumor immune evasion. Elevated CHI3L1 expression is frequently detected in cancer patients, highlighting it as a promising therapeutic target. To overcome the limited availability of small molecule CHI3L1 inhibitors, we established a surface plasmon resonance (SPR)-based high-throughput screening platform and applied it to a focused chemical library of small molecules. Primary screening identified seven hits, with compounds 1-4 and 1-7 validated as CHI3L1 binders ( Kd = 10.4 ± 1.0 μM and 7.40 ± 0.78 μM, respectively). Both compounds disrupted the CHI3L1-galectin-3 interaction in AlphaLISA assays and engaged the CHI3L1 binding pocket in docking and molecular dynamics (MD) simulations. Importantly, functional evaluation in a multicellular 3D glioblastoma (GBM) spheroid model demonstrated that compound 1-7 potently reduced spheroid viability and inhibited STAT3 phosphorylation, outperforming both compound 1-4 and the known CHI3L1-STAT3 disruptor hygromycin B (HB). These findings validate SPR as a robust primary screening platform for CHI3L1 and demonstrate that the identified small molecule binders exert functional activity in a physiologically relevant multicellular GBM spheroid model.
Insights
Researchers identified small molecule inhibitors targeting Chitinase-3-like 1 (CHI3L1), a protein linked to cancer. These inhibitors show promise in disrupting cancer growth and immune evasion mechanisms in glioblastoma models.
Area of Science:
- Biochemistry
- Oncology
- Drug Discovery
Background:
- Chitinase-3-like 1 (CHI3L1) is a key protein involved in cancer development and immune evasion.
- Elevated CHI3L1 levels are common in cancer patients, making it a significant therapeutic target.
Purpose of the Study:
- To develop novel small molecule inhibitors for CHI3L1.
- To establish and validate a high-throughput screening platform for identifying CHI3L1 binders.
Main Methods:
- Surface plasmon resonance (SPR) for high-throughput screening of small molecules.
- AlphaLISA assays to assess CHI3L1-galectin-3 interaction disruption.
- Molecular docking and dynamics simulations to analyze compound binding.
- 3D glioblastoma spheroid models for functional evaluation.
Main Results:
- Identified and validated two CHI3L1 binders, compounds 1-4 and 1-7, with dissociation constants (Kd) in the low micromolar range.
- Demonstrated that compound 1-7 effectively reduces glioblastoma spheroid viability and inhibits STAT3 phosphorylation.
- Confirmed the disruption of CHI3L1-galectin-3 interaction by the identified compounds.
Conclusions:
- SPR is a reliable platform for screening CHI3L1 inhibitors.
- Compound 1-7 exhibits potent anti-cancer activity in a relevant glioblastoma model.
- The identified small molecules represent promising leads for developing CHI3L1-targeted cancer therapies.
