Identification of CXCL8 as a potential gene associated with lymph node metastasis in papillary thyroid carcinoma through bioinformatics analysis.

CXC chemokine ligand 8 (CXCL8) has emerged as a critical mediator in tumorigenesis. This study aims to elucidate the role of CXCL8 in the initiation and progression of papillary thyroid carcinoma (PTC). Comprehensive bioinformatic analyses were conducted to assess CXCL8 expression across pan-cancer datasets, clinical characteristics, biological functions, the tumor immune microenvironment, and single-cell RNA-sequencing data. The expression of CXCL8 and its association with clinicopathological features were validated using qRT-PCR and immunohistochemical analysis of tissue microarrays. The data revealed a significantly elevated expression of CXCL8 in PTC tissues compared to Paired non-cancerous thyroid tissues(PNTs), with CXCL8 expression showing a strong positive correlation with lymph node metastasis. These findings suggest that CXCL8 may function as a key molecular contributor to lymph node metastasis in PTC. CXCL8 is likely to promote tumor cell proliferation, migration, and invasion via the PI3K-Akt signaling pathway. Moreover, CXCL8 expression is closely associated with tumor-infiltrating immune cells, particularly exhibiting high expression levels in dendritic cells. In patients with low CXCL8 expression, anti-CTLA-4 immunotherapy may offer superior clinical benefit compared to anti-PD-1 treatment. Collectively, these findings indicate that CXCL8 represents a promising biomarker involved in the pathobiology of PTC and constitutes a potential therapeutic target, providing novel insights into immunotherapeutic strategies for PTC.