A novel triazole, NMK-T-057, induces autophagic cell death in breast cancer cells by inhibiting γ-secretase–mediated activation of Notch signaling

• Published in: The Journal of biological chemistry 2019-04, Vol.294 (17), p.6733-6750
• Main Authors: Das, Amlan, Narayanam, Maruthi Kumar, Paul, Santanu, Mukhnerjee, Pritha, Ghosh, Suvranil, Dastidar, Debabrata Ghosh, Chakrabarty, Subhendu, Ganguli, Arnab, Basu, Biswarup, Pal, Mahadeb, Chatterji, Urmi, Banerjee, Sushanta K., Karmakar, Parimal, Kumar, Dalip, Chakrabarti, Gopal
• Format: Article
• Language: English
• Subjects: Amyloid Precursor Protein Secretases - antagonists & inhibitors; Amyloid Precursor Protein Secretases - metabolism; Animals; apoptosis; Apoptosis - drug effects; autophagy; Autophagy - drug effects; breast cancer; Breast Neoplasms - enzymology; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Carcinogenesis - drug effects; Cell Biology; Cell Line, Tumor; Down-Regulation - drug effects; drug design; Epithelial-Mesenchymal Transition - drug effects; Humans; Mice; Mice, Inbred BALB C; Receptors, Notch - metabolism; Signal Transduction; triazole; Triazoles - pharmacology; Xenograft Model Antitumor Assays; γ-secretase
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.RA119.007671

Notch signaling is reported to be deregulated in several malignancies, including breast, and the enzyme γ-secretase plays an important role in the activation and nuclear translocation of Notch intracellular domain (NICD). Hence, pharmacological inhibition of γ-secretase might lead to the subsequent inhibition of Notch signaling in cancer cells. In search of novel γ-secretase inhibitors (GSIs), we screened a series of triazole-based compounds for their potential to bind γ-secretase and observed that 3-(3′4′,5′-trimethoxyphenyl)-5-(N-methyl-3′-indolyl)-1,2,4-triazole compound (also known as NMK-T-057) can bind to γ-secretase complex. Very interestingly, NMK-T-057 was found to inhibit proliferation, colony-forming ability, and motility in various breast cancer (BC) cells such as MDA-MB-231, MDA-MB-468, 4T1 (triple-negative cells), and MCF-7 (estrogen receptor (ER)/progesterone receptor (PR)–positive cell line) with negligible cytotoxicity against noncancerous cells (MCF-10A and peripheral blood mononuclear cells). Furthermore, significant induction of apoptosis and inhibition of epithelial-to-mesenchymal transition (EMT) and stemness were also observed in NMK-T-057–treated BC cells. The in silico study revealing the affinity of NMK-T-057 toward γ-secretase was further validated by a fluorescence-based γ-secretase activity assay, which confirmed inhibition of γ-secretase activity in NMK-T-057–treated BC cells. Interestingly, it was observed that NMK-T-057 induced significant autophagic responses in BC cells, which led to apoptosis. Moreover, NMK-T-057 was found to inhibit tumor progression in a 4T1-BALB/c mouse model. Hence, it may be concluded that NMK-T-057 could be a potential drug candidate against BC that can trigger autophagy-mediated cell death by inhibiting γ-secretase–mediated activation of Notch signaling.