Comparative proteomics of primary breast carcinomas and lymph node metastases outlining markers of tumor invasion.

Lymph node metastasis is an important clinicopathological parameter for breast cancer prognostication and treatment. Although the development of metastasis is common in axillary lymph nodes, the mechanisms underlying the locoregional spread are yet poorly understood. In the present study, we outline the involvement of proteins in tumor invasion by comparing the proteome profile of primary breast tumors (PBT) against that of lymph node metastasis (LNM). The comparative proteome analyses of seven paired samples were performed using two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). Recurrent proteins were differentially expressed in PBT and LNM across patients. Higher levels of 1433G, 1433T, K2C8, PSME2, SNAA, TPM4, TRFE and VIME were observed in primary tumors compared to the metastatic site. On the other hand, higher levels of ALDH2 and GDIR2 were identified in metastasis related to tumors. These proteins provide a new insight on breast cancer research. Our achievements strengthened previous omics-based studies and also support the validation of potential markers of tumor invasion and metastasis.