Comprehensive Cytokine Gene Expression and Multiplex Analysis in Breast Cancer Patients: Insights Into Immune...

Cytokines are small, soluble proteins secreted by various cells. They are the key mediators of inflammation and immune modulation and play crucial roles in tumor progression, immune evasion, and therapeutic resistance. Cytokines play a pivotal role in breast cancer, influencing tumor initiation, progression, and metastasis. This study aimed to perform an integrative multiplex cytokine profiling and subsequent tissue cytokine expression (gene and protein) analysis to identify immune signatures and potential biomarkers associated with breast cancer progression and clinical parameters.

A prospective case-control study involving 90 breast cancer patients and 60 age-matched healthy controls was conducted. Peripheral blood was collected for a Luminex-based multiplex assay to analyze 17 cytokines (pro-inflammatory and anti-inflammatory cytokines). Tumor tissue samples were used to assess the gene expression of IL-6 and IL-23 by quantitative real-time polymerase chain reaction (qRT-PCR). Tissue expression of downstream signaling targets such as B-cell lymphoma-6 (BCL-6) and myeloid cell leukemia 1 (MCL-1) was also assessed. Expression levels of pro-inflammatory and immunosuppressive cytokines were evaluated and correlated with clinicopathological features, including tumor stage, grade, hormone receptor status, and menopausal state.

Breast cancer patients demonstrated significantly elevated plasma levels of IL-1β, IL-6, IL-8, IL-12 (p40), granulocyte colony-stimulating factor (G-CSF), tumor necrosis factor-alpha (TNF-α), and monocyte chemoattractant protein 1 (MCP-1) compared to controls. Gene expression of IL-6 and IL-23 was markedly upregulated in tumor tissues and significantly associated with advanced stage (P < 0.001), grade 3 histology (P < 0.001), and hormone receptor-positive status (P = 0.023). Downstream targets BCL-6 and MCL-1 showed increased expression, correlating with disease aggressiveness (advanced stage and high tumor grade, P < 0.001). MCL-1 protein expression, evaluated by immunohistochemistry, was significantly associated with advanced pathological stage (P = 0.005), post-menopausal status (P < 0.001), and lymph node involvement (P = 0.003). Cytokine intercorrelation analysis suggested a complex immune network, indicating that cytokine expression may influence or reflect broader immune dynamics within the tumor microenvironment.

This study highlights distinct cytokine expression profiles in breast cancer, with IL-6, MCP-1, and MCL-1 emerging as potential biomarkers for disease progression and molecular subtype differentiation. These cytokines hold potential as both prognostic biomarkers and therapeutic targets. Future studies incorporating spatial technologies and functional assays will be crucial in translating these findings into clinically actionable strategies for precision oncology.