Effects Of Calpastatin Peptide And Calpain Inhibitor ? On Metabolism Of C2C12 Myoblasts In Tumor Microenvironment

Objective:To explore effects of Calpastatin Peptide and Calpain Inhibitor IV on metabolism of C2C12 myoblasts in tumor microenvironment and its mechanism. Methods: C2C12 myoblasts and CT26 cells were cocultured by transwell, and randomly divided into 4 groups: Blank group(DMSO, C2C12 myoblasts in monolayer culture), group A(DMSO), and group B(1u M Calpastatin Peptide), and group C(50u M Calpain Inhibitor IV). After 6,24,48,72 hours of treatment, immunocytochemistry were used to detect protein levels of Tau in C2C12 myoblasts. Removing blank group, western blot were used to determine protein levels of calpain3, atrogin1, and caspase3 in C2C12 myoblasts at different time points as described above.Results: 1. Immunohistochemical results showed that protein levels of Tau in blank group and group B were respectively higher than that in group A(P<0.05) in 6 hours after intervention. Protein levels of Tau in group B decreased(P<0.05), while that in blank group and group C increased, respectively(P<0.05), compared with group A in 24 hours. Protein levels of Tau in blank group and group C were respectively higher than that in group A(P<0.05) during period of 48 to 72 hours.2. Western blot results revealed that protein levels of caspase3 in group B and atrogin1 in group C were increased and decreased(P<0.05), respectively, compared with group A in 24 hours. Protein levels of atrogin1 and caspase3 in group C decreased(P<0.05), respectively, compared with group A during period of 48 to 72 hours.Conclusion: Degradation of Tau were completely blocked by Calpastatin Peptide through inhibiting activity of calpain1 in early stage and reduced to certain extent by Calpain Inhibitor IV through inhibition of ubiquitin proteasome system and apoptosis in advanced stage.