| Autor: |
Rentz LE; Division of Exercise Physiology, Department of Human Performance, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Whetsell MA; Division of Exercise Physiology, Department of Human Performance, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Clayton SA; Division of Exercise Physiology, Department of Human Performance, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Mizener AD; Cancer Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Holásková I; Office of Statistics, West Virginia Agriculture and Forestry Experiment Station, Davis College of Agriculture, Natural Resources and Design, West Virginia University, Morgantown, WV 26506, USA.; Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Chapa MG; Cancer Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Hoblitzell EH; Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Eubank TD; Cancer Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA.; Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA., Pistilli EE; Division of Exercise Physiology, Department of Human Performance, West Virginia University School of Medicine, Morgantown, WV 26506, USA.; Cancer Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA.; Department of Microbiology, Immunology, and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA. |
| Abstrakt: |
Breast cancer incidence in men is statistically rare; however, given the lack of screening in males, more advanced stages at initial diagnosis result in lower 5-year survival rates for men with breast cancer compared to women. A sexual dimorphism, with respect to the effect of tumor growth on cachexia incidence and severity, has also been reported across cancer types. The purpose of this study was to examine the sexual dimorphism of breast cancer as it pertains to skeletal muscle function and molecular composition. Using female and male transgenic PyMT mice, we tested the hypothesis that the isometric contractile properties and molecular composition of skeletal muscle would be differentially affected by breast tumors. PyMT tumor-bearing mice of each sex, corresponding to maximal tumor burden, were compared to their respective controls. RNA sequencing of skeletal muscle revealed different pathway alterations that were exclusive to each sex. Further, differentially expressed genes and pathways were substantially more abundant in female tumor mice, with only minimal dysregulation in male tumor mice, each compared to their respective controls. These differences in the transcriptome were mirrored in isometric contractile properties, with greater tumor-induced dysfunction in females than male mice, as well as muscle wasting. Collectively, these data support the concept of sexually dimorphic responses to cancer in skeletal muscle and suggest that these responses may be associated with the clinical differences in breast cancer between the sexes. The identified sex-dependent pathways within the muscle of male and female mice provide a framework to evaluate therapeutic strategies targeting tumor-associated skeletal muscle alterations. |
