Cisplatin-based Electrochemotherapy Significantly Downregulates Key Heat Shock Proteins in MDA-MB-231-Human Triple-Negative Breast Cancer Cells

Heat shock proteins (HSPs) are available and/or induced for the survival of all organisms, including eukaryotic, prokaryotic, and plants, from higher temperature stresses. They are the chaperone proteins that protect all cells against heat, as the name implies. In addition to thermal stress, they also protect them from chemical, physical, and other stresses, including exposure to oxidative stress, nutritional deficiencies, ultraviolet radiation, ethanol, viral infection, ischemia–reperfusion injury, and cancer-related stresses. They are classified based on their molecular weights in kDa, such as HSP90 and HSP70. In our label-free, high-throughput, quantitative LC–MS/MS-based proteomic studies of MDA-MB-231, human, triple-negative breast cancer cells, treated with electrical pulses (EP) and cisplatin (CsP), we identified a number of HSPs, such as HSP90AA1, and others to be significantly downregulated in EP + CsP, compared to CsP alone. This indicates that cells will undergo apoptotic cell death and hence could cause effective cancer cure/treatment. Considering that over 2 million new cases and over 600,000 deaths in 2020, of which ~ 15% are TNBC, heat shock proteins could be the untapped resources, available for the next biomarkers and/or inhibitors for new/additional therapies.