Background: Stimulation of toll-like receptors (TLRs) has been linked to the development of esophageal and gastric cancers.
Objectives: The aim of the study was to evaluate the clinical significance of tissue expression and serum concentration of TLR-2, TLR-4, TLR-7 and TLR-9 in patients with esophageal squamous cell carcinoma and gastro-esophageal junction adenocarcinoma.
Material and methods: The study group consisted of 97 individuals: 32 with esophageal squamous cell carcinoma, 27 with gastro-esophageal junction cancer, and 38 ageand gender-matched controls. The mRNA expression and protein concentration of TLRs in tissues and sera were measured by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) tests.
Results: In esophageal cancer patients, mRNA expressions of TLR-2, TLR-4 and TLR-7, and protein concentrations of all TLRs were significantly higher in tumor than in control tissue (p < 0.05). In esophageal cancer patients with lymph node metastasis, a tendency toward higher protein concentrations of tumor TLR-4 was observed. In gastro-esophageal junction adenocarcinoma subgroup, only the mRNA expression of TLR-7 and protein concentrations of TLR-4, TLR-7 and TLR-9 were significantly higher in tumors than in normal mucosa (p < 0.05). Protein concentration of TLR-9 was significantly higher in tumors of gastro-esophageal junction cancer with lymph node metastasis and depth of tumor invasion. Diagnostic potential of serum TLR-4 as a marker of gastro-esophageal junction cancer presence was reported.
Conclusions: We demonstrated differences in the expression patterns of TLRs between esophageal squamous cell carcinoma and adenocarcinoma of gastro-esophageal junction, and showed circulating TLR-4 to be a potential marker of gastro-esophageal junction cancer.
Keywords: biomarkers; gastro-esophageal cancer; toll-like receptors.