ABSTRACT
Background. Interleukin-4 (IL-4) together with interleukin-13 (IL-13) play an important role in inflammation and wound repair, and are known to be upregulated in human skeletal muscle after strenuous physical exercise. Additionally, these cytokines may act as autocrine growth factors in pancreatic cancer cells. We hypothesize that IL-4, IL-13, and their corresponding receptors are involved in mechanism of cancer cachexia.
Methods. Tissue samples from human skeletal muscle, white fat, liver, healthy pancreas, and pancreatic ductal adenocarcinoma were analyzed by quantitative real-time polymerase chain reaction for mRNA expression levels of IL-4, IL-13, IL-4 receptor α, and IL-13 receptor α1.
Results. We demonstrate for the first time that liver IL-4 mRNA is downregulated in vivo in patients with pancreatic cancer and cachexia. Additionally, IL-4 mRNA in the liver inversely correlated with musculus psoas thickness.
Conclusion. We speculate that suppression of IL-4 is involved in cancer cachexia, although the exact mechanisms have to be further elucidated.
Acknowledgments
We thank Mrs. Thea Hamma for technical support in laboratory work. This work was done in the Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany, and in the Division of Sports and Rehabilitation Medicine, Department of Internal Medicine II, University of Ulm, Leimgrubenweg 14, 89075, Ulm, Germany.
Funding
This work was supported by the German Research Foundation (DFG) and the Technische Universität München within the funding programme Open Access Publishing for Olga Prokopchuk as corresponding author.
Conflict of interest
Jürgen M. Steinacker, Ulrich Nitsche, Jeannine Bachmann, Helmut Friess, Elaine C. Schubert, Stephanie Otto, and Marc Martignoni declare that they have no conflict of interest.