Temperature-Related Intensity Change (TRIC)-based High Throughput Screening Platform for the Discovery of CHI3L1-Targeted Small Molecules

Abstract

Chitinase-3-like 1 (CHI3L1) protein is a secreted glycoprotein involved in various normal physiological processes, while its abnormal elevation is closely associated to carcinogenesis. CHI3L1 promotes tumor progression by recruiting and polarizing immune cells to sustain an immunosuppressive microenvironment, while directly stimulating cancer cell proliferation and migration. Although CHI3L1 deletion has shown therapeutic potential in animal models, the development of small molecule modulators remains limited. To address this gap, we developed a TRIC-based high-throughput screening (HTS) platform for CHI3L1 binding and applied it to a 5,280-compound library, yielding 11 binders (hit rate: 0.21%). Of these, three compounds (9N05, 11C19, and 3C13) were validated by surface plasmon resonance (SPR). Among the validated hits, 9N05 showed the strongest binding affinity to CHI3L1 (Kd = 202.3 {+/-} 76.6 M) but only weak inhibition of CHI3L1/galectin-3 interaction. In contrast, 11C19 significantly disrupted this interaction (73.9 {+/-} 7.9% inhibition at 100 M; IC50 = 188.6 {+/-} 0.18 M). This proof-of-concept study establishes TRIC-based screening as a viable approach for identifying CHI3L1-targeted small molecules and supports its use in future modulator discovery.