Serum Interleukin-24 Levels in Gastric and Breast Cancers and Non-cancerous Inflammations

Background: Human interleukin-24 (IL-24) is a cytokine belonging to the interleukin-10 (IL-10) family of cytokines, also known as melanoma differentiation- associated gene 7, due to its discovery as a tumor-suppressing protein. A tumor-suppressing protein, IL-24 is produced by a variety of cells, including cancerous and non-cancerous healthy cells. The aim of the present study was to evaluate serum IL-24 concentrations in different cancers and compare them with non-cancerous inflammations. Method: In this case-control study, we divided a total of 200 subjects into five groups of 40 control subjects without cancer and without Helicobacter Pylori (H. Pylori) infection, patients with gastric cancer and H. Pylori infection, patients with H. Pylori infection without cancer, and patients with breast cancer and without H. Pylori infection. We measured the serum IL-24 level using specific enzyme-linked immunosorbent assay (ELISA) kit; we analysed the data with SPSS software. Results: The level of IL-24 was significantly higher in breast cancer group (160.65±55pg/mL) (mean± SD) followed by gastric cancer with (76.2±16.27 pg/mL) (mean±SD) and without (72.5±17.84 pg/mL) (mean± SD) H. Pylori infection groups. The level of IL-24 in H. Pylori infected patients and controls were (32.78±12.96 pg/mL) (mean±SD) and (27.4±8.5 pg/mL (mean±SD)), respectively. Conclusion: The mechanisms by which IL-24 is produced may be different between immune and cancer cells and serum IL-24 is more likely generated by immune cells than tumor cells. In breast cancer patients, estrogen or other sex hormones may provoke IL-24 production.