Supplementary Material for: High expression of cancer-derived sialylated immunoglobulin G: a novel biomarker for poor prognosis in laryngeal squamous cell carcinoma

Introduction: Laryngeal squamous cell carcinoma (LSCC) is the most common type of laryngeal cancer, with around 60% of patients being diagnosed at an advanced stage. Recently, cancer-derived sialylated immunoglobulin G (SIA-IgG) has been suggested to play a role in the progression of various epithelial tumors, but its significance in LSCC remains unknown. This study aims to investigate the clinical significance of SIA-IgG as a novel biomarker in relation to the initiation, progression, and prognostication of LSCC.
Methods: Immunohistochemistry (IHC) were utilized to assess SIA-IgG expression in tumor samples from 75 LSCC patients, aiming to investigate its correlation with clinical prognosis. Vitro functional experiments were conducted to explore the impact of SIA-IgG expression on the proliferative and migratory abilities of laryngocarcinoma cells.
Results: High expression of SIA-IgG was associated with pT stage, pN stage, TNM stage, and recurrence during follow-up, and was correlated with poor disease-free survival (DFS) and overall survival (OS). Multivariate Cox analysis demonstrated that SIA-IgG served as an independent risk factor for OS and DFS. Knocking down SIA-IgG significantly weakened laryngocarcinoma cells' proliferation, clonogenesis, and migration abilities.
Conclusions: The frequent expression of SIA-IgG in LSCC is significantly associated with poor prognosis. High levels of SIA-IgG can enhance proliferation and migration in laryngocarcinoma cells. These findings suggest that SIA-IgG has potential as a novel biomarker for LSCC.