Proteomic studies of B16 lines: Involvement of Annexin A1 in melanoma dissemination

To identify proteins involved in melanoma metastasis mechanisms, comparative proteomic studies were undertaken oil B16FI0 and B16B16 melanoma cell lines and their Subsequent syngenic primary tumours as pulmonary metastases were present only in the mice bearing a 13161316 turnout. 2DE analyses followed by MALDI-TOF identification showed variations of 6 proteins in vitro and 13 proteins in vivo. Differential expressed proteins in tumours were related to energy production and storage. Two differentially expressed proteins which had not been Previously associated to melanoma progression, annexin A] (ANXA1) and creatine kinase B (CKB), were found both in cells and in tumours. To characterize ANXA1 involvement in melanoma 1316 dissemination, we reduced ANXA1 protein level by siRNA and observed a significant decrease of 13161316 cell invasion through Matrigel coated chambers. We further demonstrated that the presence of several formyl peptide receptors (FPR1, FPRrs1 and 2) revealed by qRT-PCR, played a role in 1316 invasion: incubation of 13161316 cells with the FPR agonist (fMLP) or antagonist (tBOC) enhanced or decreased Matrigel coated chamber invasion respectively, with a correlation of ANXA1 levels in both treatments. As ANXA1 could bind to FPRs, this should amplify invasion and enhance melanoma dissemination. (C) 2008 Elsevier B.V. All rights reserved.