Birinapant Enhances Gemcitabine's Antitumor Efficacy in Triple-Negative Breast Cancer by Inducing Intrinsic Pathway-Dependent Apoptosis.

Journal Article (Journal Article)

Triple-negative breast cancer (TNBC) is the most aggressive subgroup of breast cancer, and patients with TNBC have few therapeutic options. Apoptosis resistance is a hallmark of human cancer, and apoptosis regulators have been targeted for drug development for cancer treatment. One class of apoptosis regulators is the inhibitors of apoptosis proteins (IAPs). Dysregulated IAP expression has been reported in many cancers, including breast cancer, and has been shown to be responsible for resistance to chemotherapy. Therefore, IAPs have become attractive molecular targets for cancer treatment. Here, we first investigated the antitumor efficacy of birinapant (TL32711), a biindole-based bivalent mimetic of second mitochondria-derived activator of caspases (SMACs), in TNBC. We found that birinapant as a single agent has differential antiproliferation effects in TNBC cells. We next assessed whether birinapant has a synergistic effect with commonly used anticancer drugs, including entinostat (class I histone deacetylase inhibitor), cisplatin, paclitaxel, voxtalisib (PI3K inhibitor), dasatinib (Src inhibitor), erlotinib (EGFR inhibitor), and gemcitabine, in TNBC. Among these tested drugs, gemcitabine showed a strong synergistic effect with birinapant. Birinapant significantly enhanced the antitumor activity of gemcitabine in TNBC both in vitro and in xenograft mouse models through activation of the intrinsic apoptosis pathway via degradation of cIAP2 and XIAP, leading to apoptotic cell death. Our findings demonstrate the therapeutic potential of birinapant to enhance the antitumor efficacy of gemcitabine in TNBC by targeting the IAP family of proteins.

Full Text

Duke Authors

Cited Authors

  • Xie, X; Lee, J; Liu, H; Pearson, T; Lu, AY; Tripathy, D; Devi, GR; Bartholomeusz, C; Ueno, NT

Published Date

  • February 2021

Published In

Volume / Issue

  • 20 / 2

Start / End Page

  • 296 - 306

PubMed ID

  • 33323457

Pubmed Central ID

  • 33323457

Electronic International Standard Serial Number (EISSN)

  • 1538-8514

Digital Object Identifier (DOI)

  • 10.1158/1535-7163.MCT-19-1160


  • eng

Conference Location

  • United States