35 | A novel 3D skeletal muscle model to study cancer cachexia

R. Wüst¹, L. Terrie¹, A. Weisrock^1|2, L. Thorrez¹, Emanuele Berardi¹ | ¹Tissue Engineering Lab, Department of Development and Regeneration, KU Leuven Kulak, Kortrijk, Belgium; ²Univ. Lille, CNRS, Centrale Lille, UMR 9013, LaMcube, Lille, France.

Cancer cachexia is a multisystem syndrome affecting cancer patients, characterized by progressive body weight loss, muscle wasting, increased mortality and poor quality of life. Skeletal muscle represents a main target of cancer cachexia, where tumor-derived inflammatory factors including IL-1, IL-6 and TNF-α trigger muscle degeneration through the activation of specific proteolytic pathways, ultimately causing a dramatic loss of muscle mass and function. Although several mouse models have been used to study cancer cachexia, the close interaction between tumor and muscle cells has been investigated primarily in 2D in vitro co-culture models. This approach revealed important molecular and metabolic dysfunctions of muscle cells when co-cultured with tumor cells. However, the use of 2D systems to study skeletal muscle differentiation/degeneration dynamics presents many limitations, including the lack of the characteristic spatial orientation of the myotubes. Here, we present a novel hydrogel-based 3D in vitro muscle model to study cancer cachexia. We generated bio-artificial muscle and extended the model by incorporating a co-culture with colorectal carcinoma cells, enabling direct cell–cell contact between cancer cells and myogenic cells. After differentiation in co-cultures with carcinoma cells, myoblasts showed a severe impairment of their myogenic potential. This model also allows to uncouple direct cellcell contacts while studying the effect of secreted factors by an indirect co-culture system. In addition, we found that the typical myofiber alignment observed in native muscle tissue is preserved in our constructs also in the presence of carcinoma cells. The ability to study cancer-related myogenic dysfunction in a soft 3D environment represents a novel tool to study cancer cachexia mechanisms and drug development, further reducing the need for animal experiments.