Objective: Identify the molecular mechanism of inflammatory stimuli induced pancreatic cancer progression.
Methods: RNA-seq, microarray assay and bioinformatics analyses were used to identify differentially expressed genes. Immunohistochemical staining was performed to evaluate CD68, CD163, β-catenin, CD103, CCL3 markers. Quantitative real-time polymerase chain reaction (qRT-PCR), luciferase reporter assay, apoptosis assay, wound healing assay and immunofluorescence were performed to study the relationship of inflammatory stimuli and WNT/β-catenin pathway.
Results: Differentially expressed genes of macrophage-conditioned medium-treated pancreatic cancer cells were related with WNT/β-catenin pathway. Inflammatory stimuli could activate WNT/β-catenin signaling pathway. In 106 pancreatic cancer patients, nuclear β-catenin expression of CD68-high group was much higher than CD68-low group (P < 0.05), as same as CD163 (P < 0.05). Inflammatory stimuli downregulated the expression of CCL3 via WNT/β-catenin pathway and inhibited the chemotaxis of CD103 dendritic cells. Six pancreatic cancer prognosis associating genes were upregulated by inflammatory stimuli via WNT/β-catenin pathway. Transforming growth factor-β promoted malignant biological behavior of pancreatic cancer cells through WNT/β-catenin pathway-dependent mechanism.
Conclusions: Our present study provided a novel mechanism involved in the inflammation-driven cancer progression through tumor immune escape and downstream gene regulation of WNT/β-catenin pathway-dependent manner.