Urinary Proteomic/Peptidomic Biosignature of Breast Cancer Patients Using 1D SDS-PAGE Combined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry

The potential development of a rapid and highly sensitive breast cancer (BC) diagnostic method has been increasingly investigated by many researchers in order to significantly improve the diagnosis of this disease that affects millions of women worldwide. Thus, this investigation aimed to establish a potential BC urinary peptidomic pattern using one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1D SDS-PAGE) coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a useful approach for BC diagnosis. The results of Lowry’s assay demonstrated that the total protein concentration increased after precipitation and that the healthy control group (HCs, 160 to 318 µg/mL, 142 ± DD µg/mL, on average) presented higher total protein content than the BC patients (140 to 311 µg/mL, 115 ± DD µg/mL, on average). Related to MALDI-TOF MS analysis, the results revealed that four peptide ion biosignatures (m/z 1046.5, 1062.5, 1237.7 and 1727.9) allowed the discrimination between BC patients and HCs. The distinction efficiency and accuracy of BC urine peptides were determined by receiver operating characteristic (ROC) curve analysis that enabled the recognition of some features with great sensitivity (88%) and specificity (98%). Therefore, the obtained data revealed MALDI-TOF MS as a powerful tool to explore peptidomic biosignatures due to its speed, sensitivity, and mass accuracy, which allow the establishment of novel disease biomarkers.