Notch Signaling Mediates Skeletal Muscle Atrophy in Cancer Cachexia Caused by Osteosarcoma

Figure 5

Coculture of K7M2 cells and MDSCs (from normal muscle) resulted in repressed myogenesis of MDSCs and upregulated expression of Notch genes. (a) The transwell system used in this study, including the upper chamber seeded with MDSCs, K7M2 cells, or K12 cells on the cell nonpermeable filter (0.4 μm) and the lower chamber seeded with MDSCs. (b) Myogenesis (myotube formation) of cocultured MDSCs was measured by immunostaining of myosin heavy chain (MHC). K7M2 cells repressed the myogenesis potential of MSDCs, while the coadministration of DAPT could rescue the repressed myogenesis. (c) Ratio of MHC+ myotubes formed by cocultured MDSCs. replicates for each group. (d) Semiquantitative PCR revealed higher mRNA levels of Notch1 and Hes1 genes in K7M2 cells, compared to MDSCs. (e) Differential expression of Notch genes in K7M2 cells versus MDSCs. (f) Semiquantitative PCR revealed higher mRNA levels of Notch1 and Hes1 genes in MDSCs cocultured with K7M2 cells, compared to MDSCs cocultured with MDSCs. (g) Differential expression of Notch genes in MDSCs/K7M2 versus MDSCs/MDSCs. “” in the bar chart indicates .

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