Identification of Secretome of MRC-5 Fibroblast Cell Line Using Two-dimensional Electrophoresis Coupled to Mass Spectrometry

Objective: Secreted proteins from fibroblasts critically contribute to tumor microenvironment. Human embryonic lung fibroblast MRC-5cell line is a widely used model in cancer formation and progression studies. However, data regarding its secretome are poor. Method: In the present study, we used immobilized pH gradient-based two dimensional gel electrophoresis (2DE) and mass spectrometry to characterize the secretome of MRC-5 cell line. Results: In total, 21 protein spots related to 17 proteins were identified. Some of them were insulin-like growth factor-binding protein 5, epididymal secretory protein E1 (Niemann-Pick disease type C2 protein), cathepsin L, glutathione S-transferase P, ubiquitin carboxyl-terminal hydrolase isozyme L1 (PGP9.5), UPF0587 protein C1orf123, transgelin, cofilin-1, cofilin-2, and guanine nucleotide-binding protein subunit beta-2-like 1. Conclusion: Using 2DE and mass spectrometry, we identified several proteins in the conditioned media of MRC-5 cell line. The identified proteins were known to be involved in the key cellular processes. Our findings shed more light on the proteome mapping of secreted proteins from a fibroblast cell line.