Comparative proteomic analysis of ductal and lobular invasive breast carcinoma.

Breast cancer is the second most common cancer worldwide and the first among women. Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the two major histological subtypes, and the clinical and molecular differences between them justify the search for new markers to distinguish them. As proteomic analysis allows for a powerful and analytical approach to identify potential biomarkers, we performed a comparative analysis of IDC and ILC samples by using two-dimensional electrophoresis and mass spectrometry. Twenty-three spots were identified corresponding to 10 proteins differentially expressed between the two subtypes. ACTB, ACTG, TPM3, TBA1A, TBA1B, VIME, TPIS, PDIA3, PDIA6, and VTDB were upregulated in ductal carcinoma compared to in lobular carcinoma samples. Overall, these 10 proteins have a key role in oncogenesis. Their specific functions and relevance in cancer initiation and progression are further discussed in this study. The identified peptides represent promising biomarkers for the differentiation of ductal and lobular breast cancer subtypes, and for future interventions based on tailored therapy.