Updated project metadata. Overexpression of human epidermal growth factor receptor 2 (HER-2) occurs in 20% of all breast cancer subtypes, those that present the worst prognostic outcome through a very invasive and aggressive tumour. HCC-1954 (HER-2+) is a highly invasive, metastatic cell line whereas MCF-7 is mildly aggressive and non-invasive. We investigated membrane proteins from both cell lines that could have a pivotal biological significance in the metastatic process. Membrane protein enrichment for HCC-1954 and MCF-7 proteomic analysis was performed. The samples were analysed on a two-dimensional liquid chromatography coupled to mass spectrometry (2-D-SCX/RP-LCMS system) and the protein expression was quantified by MSE method. High abundance membrane proteins were confirmed by western blot, immunofluorescence, and flow cytometry. Protein interaction prediction and correlations with TCGA patient’s data were conducted by bioinformatic analysis. The comparison between HCC-1954 and MCF-7 membrane proteins revealed that proteins involved in cytoskeleton organization, such as HER-2, β-1 integrin, E-cadherin and CD166 (ALCAM) were more abundant in HCC-1954. The Cancer Genome Atlas (TCGA) analysis showed a trend toward a positive correlation between HER-2 and β-1 integrin in HER-2+ breast cancer patients. Differences in protein profile and abundance reflect distinctive capabilities for motility and invasiveness between cell lines. HCC-1954 could be an excellent model to study β1 integrin and epithelial–mesenchymal transition (EMT) involvement in trastuzumab resistance mechanisms.