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

Figure 6

Exosomes from K7M2 cells increased Notch activation and repressed the myogenesis of MDSCs, and TNF-α treatment of MDSCs repressed myogenesis by activating Notch signaling. (a) MDSCs were treated with culture medium of MDSCs, culture medium of K7M2 cells, exosomes isolated from the culture medium of K7M2 cells (K7M2 exosomes), and K7M2 exosomes plus DAPT. Myotube formation was measured with immunostaining against MHC. (b) The expression of Notch1 and Hes1 in MDSCs treated with K7M2 exosomes or MDSC exosomes was compared with semiquantitative PCR. (c) Differential expression of Notch1 and Hes1 in MDSCs/K7M2 exosome versus MDSCs/MDSC exosome. (d) Myogenesis of MDSCs with and without TNF-α treatment was compared using immunostaining of MHC. (e) TNF-α treatment (20 ng/mL) of MDSCs upregulated the expression of Notch1 and Hes1. (f) Differential expression of Notch1 and Hes1 in K7M2 with or without TNF-α treatment. “” in the bar chart indicates .

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