The synergistic effect exerted by the HDAC inhibitor SAHA and the sesquiterpene lactone parthenolide on triple negative breast canc er cells

Triple-negative breast cancer (TNBC) is a subtype o f breast cancer, insensitive to endocrine therapy. Chemotherapy is the main form of treatment, but is accompanied by a high rate of recidivism. The sesquiterpene lactone Parthenolide (PN) exerts a cy totoxic effect on MDA-MB231 cells, a TNBC cell line (1), but was ineffective at low doses (2-5μM). This repr esents an obstacle for a therapeutic utilization of PN. We supposed, in line with other authors (2), that PN c auses a protective response, which at low doses pre vails on the cytotoxic effect. With the aim of inhibiting this protective effect we have shown that pre-trea tment of MDA-MB231 cells with SAHA (2-5μM), an histone deace tylat…