Galectin-9 in non-small cell lung cancer

Area of Science:

• Oncology
• Immunology

Background:

• Lung cancer, particularly non-small cell lung cancer (NSCLC), presents a significant global health challenge with high incidence and mortality rates.
• Understanding the molecular mechanisms and biomarkers associated with NSCLC progression and patient outcomes is crucial for developing effective therapeutic strategies.

Purpose of the Study:

• To investigate the expression of galectin-9 in non-small cell lung cancer (NSCLC) tumor cells and tumor-infiltrating lymphocytes (TILs).
• To analyze the correlation between galectin-9 expression and other immune checkpoint molecules, as well as its impact on patient prognosis, including recurrence-free survival (RFS) and overall survival (OS).

Main Methods:

• The study analyzed 136 primary NSCLC tumor samples using immunohistochemistry (IHC) to assess galectin-9 protein expression.
• Correlations between galectin-9 levels and immune checkpoint markers such as T cell immunoglobulin and mucin-domain containing-3 (TIM-3), programmed cell death protein-1 (PD-1), and programmed cell death-ligand 1 (PD-L1) were evaluated.

Main Results:

• Galectin-9 expression was detected on both NSCLC tumor cells and TILs across all pathological types.
• On tumor cells, galectin-9 expression correlated with TIM-3 levels. On TILs, galectin-9 showed correlations with TIM-3, PD-1, and PD-L1.
• High galectin-9 levels on TILs were associated with shorter recurrence-free survival (RFS). Conversely, patients with galectin-9 positive tumor cells exhibited longer overall survival (OS).

Conclusions:

• Galectin-9 is expressed in NSCLC and its levels on tumor cells and TILs have distinct prognostic implications.
• Low galectin-9 expression on tumor cells may be linked to a poorer prognosis, whereas high galectin-9 expression on TILs suggests an unfavorable outcome.
• These findings highlight galectin-9 as a potential biomarker for predicting NSCLC patient prognosis and response to immunotherapy.