ixazomib and Breast-Neoplasms

Multiple myeloma is a hematological cancer characterized by relapse after treatment and poor prognosis. Ixazomib, a second-generation protease inhibitor, is one of the most recently available treatments for relapsed or refractory multiple myeloma, while it has also shown good potential as antitumoral agent in preclinical solid tumor models such as breast cancer cell lines. Here we report the case of a 68-year-old female with multiple myeloma and an incidental cT1b (9 mm) hormone receptor positive breast cancer lesion that showed a complete pathological response to a three-month combination therapy with Ixazomib, bendamustine and dexamethasone and no signs of disease relapse during the later follow-up. This is the first case report describing such clinical outcome in breast cancer following Ixazomib, bendamustine and dexamethasone combination therapy. To investigate the potential antitumoral activity of Ixazomib in breast cancer, we performed

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Bendamustine Hydrochloride; Breast Neoplasms; Dexamethasone; Female; Humans; Multiple Myeloma; Neoplasm Recurrence, Local; Recurrence

Doxorubicin (Dox), one of the most effective chemotherapy drug for cancer treatment, is limited by its severe side effects and chemoresistance. Dox induces DNA damage and leads to significant proteomic changes in the cancer cells, which makes the ubiquitin-proteasome system a potential target to enhance the efficacy of Dox therapy. The unsuccessful clinical trials of proteasome inhibitor PS-341 (bortezomib) in solid tumors led to the invention of MLN9708 (ixazomib), an orally bioavailable next-generation proteasome inhibitor with improved pharmacokinetic and pharmacodynamic features. In this preclinical study, we used eight human breast cancer cell lines, which represent the major molecular subtypes of breast cancer, to validate the cytotoxic effects of MLN9708, alone and in combination with Dox. We found that MLN9708 had cytotoxic effects, induced autophagy and MKP-1 expression, and enhanced Dox-induced apoptosis in these cell lines. MLN9708 also enhanced Dox-induced JNK and p38 phosphorylation and inhibited Dox-induced IκBα degradation. Our in vitro results suggest that MLN9708 has antitumor effects in breast cancer and can sensitize breast cancer cells to Dox treatment. This promising combination may be an effective and feasible therapeutic option for treating breast cancer and warrants clinical validation.

Topics: Autophagy; Boron Compounds; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Doxorubicin; Drug Screening Assays, Antitumor; Drug Synergism; Dual Specificity Phosphatase 1; Female; Gene Expression Regulation, Neoplastic; Glycine; Humans; MAP Kinase Signaling System; MCF-7 Cells; Phosphorylation; Proteasome Inhibitors