CD137 Protein Expression Pattern Determines the Functional Role of Galectin-9 in Colorectal Cancer

The rapid advancement of single-cell sequencing technology has generated extensive data, providing critical resources for colorectal cancer (CRC) research. This study conducts a detailed analysis of CRC single-cell sequencing data to develop a novel clinical prognostic tool and explore potential therapeutic targets for the LGALS9 gene. Using the Scissor algorithm, we created a CRC prognostic scoring system (SDRS) based on 13 key genes, with particular focus on LGALS9 and its protein, Galectin-9, in mice CRC model with altered CD137 expression. Our findings demonstrate that the SDRS accurately reflects clinical and pathological features of CRC patients, acting as an independent predictor of outcomes. LGALS9 expression is generally reduced in CRC tissues and is associated with poorer prognosis. We also observed a strong positive correlation between LGALS9 and CD137 expression, with CD137 showing significant variability in CRC tissues. In mouse models with CD137 overexpression, Galectin-9 treatment led to notable antitumor effects and increased infiltration of activated T cells. In contrast, in CD137-deficient models, Galectin-9 promoted tumor growth with limited T cell presence. These results suggest that the role of LGALS9 in CRC may depend on CD137 expression, highlighting the potential of LGALS9 as a therapeutic target. CD137 levels may serve as a key indicator for predicting the effectiveness of this treatment strategy.