IL-20 is a proinflammatory cytokine involved in rheumatoid arthritis, atherosclerosis, and stroke. However, little is known about its role in breast cancer.
We explored the function of IL-20 in tumor growth and metastasis, as well as in clinical outcome.
Tumor expression of IL-20 was assessed by immunohistochemical staining among 198 patients with invasive ductal carcinoma of the breast, using available clinical and survival data. IL-20 expression was associated with advanced tumor stage, greater tumor metastasis, and worse survival.
Reverse transcription quantitative polymerase chain reaction showed that clinical breast tumor tissue expressed higher levels of IL-20 and its receptors than did nontumorous breast tissue. IL-20 was also highly expressed in breast cancer bone-metastasis tissue.
In vitro, IL-20 upregulated matrix metalloproteinase-9, matrix metalloproteinase-12, cathepsin K, and cathepsin G, and enhanced proliferation and migration of breast cancer cells, which were inhibited by anti-IL-20 mAb 7E. In vivo, we generated murine models to evaluate the therapeutic potential of 7E, using luminescence intensity, radiological scans, and micro-computed tomography. 7E reduced tumor growth, suppressed bone colonization, diminished tumor-mediated osteolysis, and lessened bone density decrement in mice injected with breast cancer cells.
In conclusion, our results suggest that IL-20 plays pivotal roles in the tumor progression of breast cancer. IL-20 expression in breast cancer tissue is associated with a poor clinical outcome. Anti-IL-20 mAb 7E suppressed bone colonization and decreased osteolytic bone lesions. Therefore, IL-20 may be a novel target in treating breast tumor-induced osteolysis.
2012-02-06
Eng.
Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70428, Taiwan.
J Immunol. 2012 Feb;188(4):1981-91
© Galenicom 1999-2013