Synthesis of melampomagnolide B derivatives as potential anti-Triple Negative Breast Cancer agents.

Triple-negative breast cancer (TNBC) is the most malignant and aggressive subtype of breast cancer. Currently, the treatment options to TNBC are limited and the discovery of new drugs and novel therapeutic strategies for treatment of TNBC is urgently needed. In this study, a series of melampomagnolide B (MMB) derivatives were designed, synthesized, and evaluated for their anti-TNBC activities. Compound 7 and 13a showed highly potent activity against different TNBC cells with IC values ranging from 0.37 μM to 1.52 μM, which demonstrated 3.6- to 54-fold improvement comparing to the parent compound MMB. The phenotypic effect revealed that compound 7 and 13a could inhibit metastasis, induce apoptosis and arrest cell cycle distribution of TNBC cells. Furthermore, the mechanism research indicated compounds 7 and 13a bound IKKβ and inhibited the IKKβ-mediated phosphorylation of IκB and p65, then inhibited the nuclear translocation of p65 and eventually regulated the genes related to metastasis, apoptosis and cell cycle under NF-κB control. Moreover, compound 7 inhibited the tumor growth in vivo, and the weights of spleens and livers were also reduced compared with control group which indicated that compound 7 could inhibit metastasis of TNBC in vivo. These findings indicate that compound 7 may be used as a promising lead compound for ultimate discovery of anti-TNBC drug.