Cathepsin D inhibitors as potential therapeutics for breast cancer treatment: Molecular docking and bioevaluation against triple-negative and triple-positive breast cancers

Abstract

The main aim of this study was to discover small molecule inhibitors against Cathepsin D (CatD) (EC.3.4.23.5), a clinically proven prognostic marker for breast cancer, and to explore the mechanisms by which CatD could be a useful therapeutic target for triple-positive and triple-negative breast cancers (TPBC & TNBC). The crystal structure of CatD at 2.5 Å resolution (PDB: 1LYB), which was complexed with Pepstatin A, was selected for computer-aided molecular modeling. The methods used in our study were pharmacophore modeling and molecular docking. Virtual screening was performed to identify small molecules from an in-house database and a large commercial chemical library. Cytotoxicity studies were performed on human normal cell line HEK293T and growth inhibition studies on breast adenocarcinoma cell lines, namely MCF-7, MDA-MB-231, SK-BR-3, and MDA-MB-468. Furthermore, RT-PCR analysis, in vitro enzyme assay, and cell cycle analysis ascertained the validity of the selected molecules. A set of 28 molecules was subjected to an in vitro fluorescence-based inhibitory activity assay, and among them six molecules exhibited >50 % inhibition at 25μM. These molecules also exhibited good growth inhibition against TPBC and TNBC cancer types. Among them, molecules 1 and 17 showed single-digit micromolar GI50 values against MCF-7 and MDA-MB-231 cell lines.

Overexpression Cathepsin D Contributes to Perineural Invasion of Salivary Adenoid Cystic Carcinoma

“…In breast cancer, Achour et al and Guerra et al found that CTSD was a marker of poor prognosis and was associated with metastatic relapse of breast cancer ( 14 , 16 ). Knopfová et al reported that the elevation of CTSD expression mediated the invasion and metastasis of breast cancer in an organ-specific manner ( 28 ), and Anantaraju et al identified that CTSD inhibitors might be used as potential therapeutics for breast cancer treatment ( 29 ). In lung cancer, Giatromanolaki et al demonstrated that CTSD could enhance invasion and was closely related to poor prognosis ( 30 , 31 ).…”

Increasing intratumor C/EBP-β LIP and nitric oxide levels overcome resistance to doxorubicin in triple negative breast cancer

“…The elevated expression of the lysosomal enzyme cathepsin D has been already correlated with breast cancer progression [ 37 ], opening the way to the design of cathepsin D inhibitors as potential anti-tumor agents [ 38 ]. In the present work, we used chloroquine, a FDA-approved lysosome and autophagosome inhibitor [ 21 ] that exerts anti-tumor effects against TNBC stem cells [ 39 ] and enhances the ER stress-dependent cell death by inhibiting lysosome activity [ 40 , 41 ].…”

Impact of inducible nitric oxide synthase (iNOS) expression on triple negative breast cancer outcome and activation of EGFR and ERK signaling pathways

“…Similarly invasion through gelatin (MMP9 substrate) or collagen (MMP1 substrate) matrices was enhanced by DETA/NO, in BL2 but not in BL1 cells, reflecting results observed regarding MMPs expression and activity. However it should be noted that additional and/or more relevant mediators such as uPA/PAI-1 [ 56 ] or cathepsins [ 56 , 57 ], may play a key role in the observed effects. These effects were totally or at least partially reverted when we combined the NO donor with the EGFR or MAPK inhibitors highlighting the importance of the EGFR/MAPK pathway regulating tumor progression in a pro-inflammatory environment.…”