The role of PARP inhibition in triple-negative breast cancer: Unraveling the wide spectrum of synthetic lethality

2018 ◽  
Vol 67 ◽  
pp. 34-44 ◽  
Author(s):  
Marios Papadimitriou ◽  
Giannis Mountzios ◽  
Christos A. Papadimitriou
2021 ◽  
Vol 22 (4) ◽  
pp. 2056
Author(s):  
Kitti Andreidesz ◽  
Balazs Koszegi ◽  
Dominika Kovacs ◽  
Viola Bagone Vantus ◽  
Ferenc Gallyas ◽  
...  

Triple-negative breast cancer (TNBC) has a poor prognosis as the therapy has several limitations, most importantly, treatment resistance. In this study we examined the different responses of triple-negative breast cancer line MDA-MB-231 and hormone receptor-positive breast cancer line MCF7 to a combined treatment including olaparib, a poly-(ADP ribose) polymerase (PARP) inhibitor, oxaliplatin, a third-generation platinum compound and LY294002, an Akt pathway inhibitor. We applied the drugs in a single, therapeutically relevant concentration individually and in all possible combinations, and we assessed the viability, type of cell death, reactive oxygen species production, cell-cycle phases, colony formation and invasive growth. In agreement with the literature, the MDA-MB-231 cells were more treatment resistant than the MCF7 cells. However, and in contrast with the findings of others, we detected no synergistic effect between olaparib and oxaliplatin, and we found that the Akt pathway inhibitor augmented the cytostatic properties of the platinum compound and/or prevented the cytoprotective effects of PARP inhibition. Our results suggest that, at therapeutically relevant concentrations, the cytotoxicity of the platinum compound dominated over that of the PARP inhibitor and the PI3K inhibitor, even though a regression-based model could have indicated an overall synergy at lower and/or higher concentrations.


2021 ◽  
Vol 32 ◽  
pp. S28
Author(s):  
A. Bosch ◽  
M. Cieśla ◽  
P. Cao Thi Ngoc ◽  
S. Mutukumar ◽  
G. Honeth ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 462
Author(s):  
Víctor Mayoral-Varo ◽  
María Pilar Sánchez-Bailón ◽  
Annarica Calcabrini ◽  
Marta García-Hernández ◽  
Valerio Frezza ◽  
...  

The role of Src family kinases (SFKs) in human tumors has been always associated with tyrosine kinase activity and much less attention has been given to the SH2 and SH3 adapter domains. Here, we studied the role of the c-Src-SH2 domain in triple-negative breast cancer (TNBC). To this end, SUM159PT and MDA-MB-231 human cell lines were employed as model systems. These cells conditionally expressed, under tetracycline control (Tet-On system), a c-Src variant with point-inactivating mutation of the SH2 adapter domain (R175L). The expression of this mutant reduced the self-renewal capability of the enriched population of breast cancer stem cells (BCSCs), demonstrating the importance of the SH2 adapter domain of c-Src in the mammary gland carcinogenesis. In addition, the analysis of anchorage-independent growth, proliferation, migration, and invasiveness, all processes associated with tumorigenesis, showed that the SH2 domain of c-Src plays a very relevant role in their regulation. Furthermore, the transfection of two different aptamers directed to SH2-c-Src in both SUM159PT and MDA-MB-231 cells induced inhibition of their proliferation, migration, and invasiveness, strengthening the hypothesis that this domain is highly involved in TNBC tumorigenesis. Therefore, the SH2 domain of c-Src could be a promising therapeutic target and combined treatments with inhibitors of c-Src kinase enzymatic activity may represent a new therapeutic strategy for patients with TNBC, whose prognosis is currently very negative.


2016 ◽  
Vol 38 (3) ◽  
pp. 1003-1014 ◽  
Author(s):  
Aiyu Zhu ◽  
Yan Li ◽  
Wei Song ◽  
Yumei Xu ◽  
Fang Yang ◽  
...  

Background/Aims: Androgen receptor (AR), a steroid hormone receptor, has recently emerged as prognostic and treatment-predictive marker in breast cancer. Previous studies have shown that AR is widely expressed in up to one-third of triple-negative breast cancer (TNBC). However, the role of AR in TNBC is still not fully understood, especially in mesenchymal stem-like (MSL) TNBC cells. Methods: MSL TNBC MDA-MB-231 and Hs578T breast cancer cells were exposed to various concentration of agonist 5-α-dihydrotestosterone (DHT) or nonsteroidal antagonist bicalutamide or untreated. The effects of AR on cell viability and apoptosis were determined by MTT assay, cell counting, flow cytometry analysis and protein expression of p53, p73, p21 and Cyclin D1 were analyzed by western blotting. The bindings of AR to p73 and p21 promoter were detected by ChIP assay. MDA-MB-231 cells were transplanted into nude mice and the tumor growth curves were determined and expression of AR, p73 and p21 were detected by Immunohistochemistry (IHC) staining after treatment of DHT or bicalutamide. Results: We demonstrate that AR agonist DHT induces MSL TNBC breast cancer cells proliferation and inhibits apoptosis in vitro. Similarly, activated AR significantly increases viability of MDA-MB-231 xenografts in vivo. On the contrary, AR antagonist, bicalutamide, causes apoptosis and exerts inhibitory effects on the growth of breast cancer. Moreover, DHT-dependent activation of AR involves regulation in the cell cycle related genes, including p73, p21 and Cyclin D1. Further investigations indicate the modulation of AR on p73 and p21 mediated by direct binding of AR to their promoters, and DHT could make these binding more effectively. Conclusions: Our study demonstrates the tumorigenesis role of AR and the inhibitory effect of bicalutamide in AR-positive MSL TNBC both in vitro and in vivo, suggesting that AR inhibition could be a potential therapeutic approach for AR-positive TNBC patients.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3357
Author(s):  
Hongmei Zheng ◽  
Sumit Siddharth ◽  
Sheetal Parida ◽  
Xinhong Wu ◽  
Dipali Sharma

Triple negative breast cancer (TNBC) is a heterogeneous disease and is highly related to immunomodulation. As we know, the most effective approach to treat TNBC so far is still chemotherapy. Chemotherapy can induce immunogenic cell death, release of damage-associated molecular patterns (DAMPs), and tumor microenvironment (TME) remodeling; therefore, it will be interesting to investigate the relationship between chemotherapy-induced TME changes and TNBC immunomodulation. In this review, we focus on the immunosuppressive and immunoreactive role of TME in TNBC immunomodulation and the contribution of TME constituents to TNBC subtype classification. Further, we also discuss the role of chemotherapy-induced TME remodeling in modulating TNBC immune response and tumor progression with emphasis on DAMPs-associated molecules including high mobility group box1 (HMGB1), exosomes, and sphingosine-1-phosphate receptor 1 (S1PR1), which may provide us with new clues to explore effective combined treatment options for TNBC.


2021 ◽  
Author(s):  
Ximena Minerva Bustamante-Marin ◽  
Kaylyn L. Devlin ◽  
Om Dave ◽  
Jenna L. Merlino ◽  
Shannon B. McDonell ◽  
...  

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