Antibody-based array proteomics identify proteins differentially expressed in human metastatic and non-metastatic triple negative breast cancer cells.

M P ROBERTI; MORDOH J; BARRIO MM

Chicago

Congreso; AACR Annual Meeting 2012; 2012

AACR

Triple negative breast cancers (TNBC) lacking hormone receptors (ER, PR) and HER-2 amplification are very aggressive tumors. The IIB-BR-G cell line isolated from a primary TNBC, and its spontaneous metastatic variant, IIB-BR-G-MTS6 were compared using an antibody-based protein array to characterize their expression profile. We also analyzed their growth kinetics, migration, invasiveness, lymphangiogenesis and cytoskeleton structure. Doubling times in vitro were shorter for IIB-BR-G although in vivo IIB-BR-G-MTS6 tumors grew significantly faster than IIB-BR-G. IIB-BR-GMTS6 showed higher anchorage independent growth in a clonogenic assay. IIB-BR-G-MTS6 cells showed 100% incidence of lymph node metastasis at 5-6 weeks, although no metastasis was observed for IIB-BR-G even 19 weeks after inoculation. CCL3, IL1â, CXCL1, CSF2, CSF3, IGFBP1, IL1á, IL6, IL8, CCL20, PLAUR, PlGF and VEGF were strongly up-regulated in IIB-BR-G-MTS6 compared to IIB-BR-G, while CCL4, ICAM3, CXCL12, TNFRSF18, FIGF, were the more down-regulated proteins in the metastatic cell line. IIB-BR-G-MTS6 protein expression profile was compatible with higher NF-êB activation. In vitro, IIB-BR-G displayed higher migration but IIB-BR-G-MTS6 had a higher matrigel invasion. Accordingly, IIB-BR-G-MTS6 had an up-regulated expression of MMP1, MMP9, MMP13, PLAUR and HGF as compared to IIB-BR-G. IIB-BR-G-MTS6 tumors presented higher local lymphatic invasion than IIB-BR-G but similar lymphatic vessel densities. VEGFC and VEGFA/B expression were higher both in vitro and in vivo for IIB-BR-G-MTS6. Higher vimentin expression was mainly localized in the cellular extremities in IIB-BR-G-MTS6.Our results suggest that IIB-BR-G-MTS6 have acquired an epithelial-to-mesenchymal transition phenotype, modulating tumor stroma to favor tumor growth, increase angiogenesis and promote their metastatic dissemination.