Sequential release of epigallocatechin gallate and paclitaxel from PLGA-casein core/shell nanoparticles sensitizes drug-resistant breast cancer cells.

Nanomedicines consisting of combinations of cytotoxic drugs and molecular targeted therapeutics which inhibit specific downstream signals are evolving as a novel paradigm for breast cancer therapy. This research addresses one such combination of Paclitaxel (Ptx), having several adversities related to the activation of NF-κB pathway, with Epigallocatechin gallate (EGCG), a multiple signaling inhibitor, encapsulated within a targeted core/shell PLGA-Casein nanoparticle. The sequential release of EGCG followed by Ptx from this core/shell nanocarrier sensitized Ptx resistant MDA-MB-231 cells to Ptx, induced their apoptosis, inhibited NF-κB activation and downregulated the key genes associated with angiogenesis, tumor metastasis and survival. More importantly, Ptx-induced expression of P-glycoprotein was repressed by the nanocombination both at the protein and gene levels. This combination also offered significant cytotoxic response on breast cancer primary cells, indicating its translational value. FROM THE CLINICAL EDITOR: Breast cancer is the most common cancer in women worldwide. As well as surgery, chemotherapy plays a major role in the treatment of breast cancer. The authors investigated in this article the combination use of a chemotherapeutic agent, Paclitaxel (Ptx), and an inhibitor of NF-?B pathway, packaged in a targeted nano-based delivery platform. The positive results provided a new pathway for future clinical use of combination chemotherapy in breast cancer.