scholarly journals Modulation of Early Mitotic Inhibitor 1 (EMI1) depletion on the sensitivity of PARP inhibitors in BRCA1 mutated triple-negative breast cancer cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0235025
Author(s):  
Dina Moustafa ◽  
Maha R. Abd Elwahed ◽  
Hanaa H. Elsaid ◽  
Jeffrey D. Parvin

Triple negative breast cancer (TNBC) represents approximately 10–15% of all breast cancers and has a poor outcome as it lacks a receptor target for therapy, and TNBC is frequently associated with a germline mutation of BRCA1. Poly (ADP-ribose) polymerase inhibitor (PARPi) drugs have demonstrated some effectiveness in treating BRCA1 or BRCA2 mutated breast and ovarian cancers but resistance to PARPi is common. Published results found that resistance to Olaparib, a PARPi, can be due to downregulation of EMI1 and the consequent upregulation of the RAD51 recombinase. Using a tissue culture-based cell viability assay, we extended those observations to another PARPi and to other chemotherapy drugs that affect DNA repair or the cell cycle. As we expected, EMI1 downregulation resulted in resistance to another PARPi drug, Talazoparib. EMI1 downregulation also led to resistance to other cytotoxic drugs, Cisplatin and CHK1 inhibitor. Notably, increasing the RAD51 protein expression only recapitulated some, but not all, of the effects of EMI1 depletion in conferring to the cell resistance to different PARPi and the other cytotoxic drugs. These results suggest that the downstream effects of EMI1 downregulation that contribute to PARPi resistance are increasing the concentration of RAD51 protein in the cell and blocking mitotic entry. We found that combining CHK1 inhibitor with olaparib results in restoration of sensitivity even when EMI1 expression is downregulated. This combination therapy may be a means to overcome the PARPi resistance in BRCA1-deficient TNBC cells.

2020 ◽  
Author(s):  
Dina Moustafa ◽  
Maha R. Abd Elwahed ◽  
Hanaa H. Elsaid ◽  
Jeffrey D. Parvin

AbstractTriple negative breast cancer (TNBC) represents approximately 10–15% of all breast cancers and has a poor outcome as it lacks a receptor target for therapy, and TNBC is frequently associated with a germline mutation of BRCA1. Poly (ADP-ribose) polymerase inhibitor (PARPi) drugs have demonstrated some effectiveness in treating BRCA1 or BRCA2 mutated breast and ovarian cancers but resistance to PARPi is common. Published results found that resistance to Olaparib, a PARPi, can be due to downregulation of EMI1 and the consequent upregulation of the RAD51 recombinase. Using a tissue culture-based cell viability assay, we extended those observations to another PARPi and to other chemotherapy drugs that affect DNA repair or the cell cycle. As we expected, EMI1 downregulation resulted in resistance to another PARPi drug, Talazoparib. EMI1 downregulation also led to resistance to other cytotoxic drugs, Cisplatin and CHK1 inhibitor. Surprisingly, EMI1 depletion also led to resistance to a MEK inhibitor, though this inhibitor blocks cells in G1 phase of the cell cycle and would not be expected to be sensitive to EMI1 levels. Notably, increasing the RAD51 protein expression only partially recapitulated the effects of EMI1 depletion in causing resistance to different PARPi and the other cytotoxic drugs. These results suggest that the downstream effects of EMI1 downregulation that contribute to PARPi resistance are increasing the concentration of RAD51 protein in the cell and blocking mitotic entry. We found that combining CHK1 inhibitor with olaparib results in restoration of sensitivity even when EMI1 expression is downregulated. This combination therapy may be a means to overcome the PARPi resistance in BRCA1-deficient TNBC cells.


2020 ◽  
Vol 7 (1) ◽  
pp. 55-65
Author(s):  
A. A. Kharitonova ◽  
I. A. Smirnova ◽  
M. V. Kiseleva

By far the most aggressive subtype of breast cancer is triple negative cancer. The purpose of this review is to analyze current ideas about the pathogenesis, clinical characteristics of different subtypes of triple negative breast cancer, the nature of its metastasis, mechanisms of chemoresistance. The review presents the results of modern regimens of drug therapy of triple negative breast cancer according to the publications of domestic and foreign oncologists. On the basis of various clinical studies, the effectiveness of the use of anthracyclines, taxanes in the dose-dense regime, platinum preparations and other chemotherapy drugs for the treatment of triple-negative cancer has been shown. The presented treatment regimens allow to achieve a complete morphological response in 85% of patients, to increase the rates of relapse-free and overall survival, comparable with other subtypes of breast cancer. The review highlights the possibilities of modern targeted drugs-PARP inhibitors, chk1 inhibitors UCN‑01, immunotherapy possibilities for the treatment of this aggressive subtype of breast cancer.


2011 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Omer Dizdar ◽  
Kadri Altundag

Triple-negative breast cancer is defined by the lack of estrogen receptor, progesterone receptor and HER2 expression with immunohistochemical analysis. Triplenegative breast cancers are poorly differentiated, characterized by high histological grade and occur at a younger age. Treatment options are limited as these tumors are naturally resistant to existing targeted therapies, i.e., endocrine treatment and trastuzumab. An improved understanding of the biology of TNBC has led to evaluation of DNA-damaging chemotherapy drugs and targeted agents, including poly (ADP-ribose) polymerase inhibitors, epidermal growth factor receptor inhibitors, angiogenesis inhibitors, etc., in the treatment of TNBC. This review focuses on outlining the current and emerging treatment options in patients with triple-negative breast cancer.


2011 ◽  
pp. 5-13
Author(s):  
Omer Dizdar ◽  
Kadri Altundag

Triple-negative breast cancer is defined by the lack of estrogen receptor, progesterone receptor and HER2 expression with immunohistochemical analysis. Triplenegative breast cancers are poorly differentiated, characterized by high histological grade and occur at a younger age. Treatment options are limited as these tumors are naturally resistant to existing targeted therapies, i.e., endocrine treatment and trastuzumab. An improved understanding of the biology of TNBC has led to evaluation of DNA-damaging chemotherapy drugs and targeted agents, including poly (ADP-ribose) polymerase inhibitors, epidermal growth factor receptor inhibitors, angiogenesis inhibitors, etc., in the treatment of TNBC. This review focuses on outlining the current and emerging treatment options in patients with triple-negative breast cancer.


2012 ◽  
Vol 30 (27_suppl) ◽  
pp. 107-107
Author(s):  
Behyar Zoghi ◽  
Peter Ravdin

107 Background: Approximately 15-20% of all breast cancers account for triple-negative breast cancers that exhibit aggressive, distinct metastatic pattern and poor prognosis. More than 50% of patients with triple negative breast cancers develop chemoresistance and do not respond to chemotherapeutic drugs, leading to early relapse and shorter survival. Understanding the mechanisms underlying such resistance is therefore crucial for the development of new, efficacious cancer drugs. Methods: Through high-throughput miRNA inhibitor library screens, we have identified miRNA inhibitors that sensitize resistant triple negative breast cancer cells to paclitaxel, a drug commonly used to treat triple negative breast cancers. Results: Through high-throughput miRNA inhibitor library screens, we have identified miRNA inhibitors that sensitize resistant triple negative breast cancer cells to paclitaxel, a drug commonly used to treat triple negative breast cancers. Since miRNAs are endogenously expressed and can be easily manipulated using synthetic oligoribonucleotides, we believe that they represent more attractive targets than the single gene or gene product that is the target of conventional cancer treatments that are typically prone to drug resistance. Supporting this, we have recently demonstrated that miRNAs can be systemically delivered to treat breast cancer lung metastasis without any hepatotoxicity. In addition to being a potent therapeutic regimen, our preliminary analyses reveal that miRNAs can be bonafide early prognostic markers to monitor treatment response to specific drugs in triple-negative breast cancers. Conclusions: Taken together, these findings suggest that miRNA can serve as potent therapeutic adjuvants and although the data content of miRNA profiles is far less than that of gene expression profiles, by virtue of their ability to modulate entire spectrum of genes and pathways miRNAs have potential to be better classifiers for the prognosis and response to treatment of cancers. We believe that the identification of miRNAs that mediate chemoresistance could lead to more efficient treatment selection at the patient level and an improved response rates at the population level.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Ayca Gucalp ◽  
Tiffany A. Traina

Triple-negative breast cancer (TNBC), a subtype distinguished by negative immunohistochemical assays for expression of the estrogen and progesterone receptors (ER/PR) and human epidermal growth factor receptor-2(HER2) represents 15% of all breast cancers. Patients with TNBC generally experience a more aggressive clinical course with increased risk of disease progression and poorer overall survival. Furthermore, this subtype accounts for a disproportionate number of disease-related mortality in part due to its aggressive natural history and our lack of effective targeted agents beyond conventional cytotoxic chemotherapy. In this paper, we will review the epidemiology, risk factors, prognosis, and the molecular and clinicopathologic features that distinguish TNBC from other subtypes of breast cancer. In addition, we will examine the available data for the use of cytotoxic chemotherapy in the treatment of TNBC in both the neoadjuvant and adjuvant setting and explore the ongoing development of newer targeted agents.


2014 ◽  
Vol 17 (3) ◽  
pp. 439 ◽  
Author(s):  
Wayne Goh ◽  
Inna Sleptsova-Freidrich ◽  
Nenad Petrovic

PURPOSE: Triple negative breast cancers (estrogen, progesterone and human epidermal growth factor 2 (HER2) receptor-negative) are among the most aggressive forms of cancers with limited treatment options. Doxorubicin is one of the agents found in many of the current cancer treatment protocols, although its use is limited by dose-dependent cardiotoxicity. This work investigates one of the ways to suppress cancer growth by inhibiting tumor cell ability to remove acid accumulated during its metabolism by proton pump inhibitor esomeprazole (a drug with extensive clinical use) which could serve as an addition to doxorubicin therapy. METHODS: In this work, we have investigated growth suppression of triple-negative breast cancer cells MDA-MB-468 by esomeprazole and doxorubicin by trypan blue exclusion assay. Measurement of acidification of treated cancer cells was performed using intracellular pH-sensitive probe, BCECF-AM. Finally, expression of gastric type proton pump (H+/K+ ATPase, a target for esomeprazole) on MDA-MB-468 cells was detected by immunofluorescence and Western blotting. RESULTS: We have found that esomeprazole suppresses growth of triple-negative breast cancer cell in vitro in a dose-dependent manner through increase in their intracellular acidification. In contrast, esomeprazole did not have significant effect on non-cancerous breast epithelial MCF-10A cells. Esomeprazole increases doxorubicin effects suggesting that dual treatments might be possible. In addition, response of MDA-MB-468 cells to esomeprazole could be mediated by gastric type proton pump (H+/K+ ATPase) in cancer cells contrary to previous beliefs that this proton pump expression is restricted to parietal cells of the stomach epithelia. CONCLUSION: This study provides first evidence that adjunct use of esomeprazole in breast cancer treatment might be a possible to combat adverse effects of doxorubicin and increase its effectiveness. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.


Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 259
Author(s):  
Madhuchhanda Kundu ◽  
Sumita Raha ◽  
Avik Roy ◽  
Kalipada Pahan

Although some therapies are available for regular breast cancers, there are very few options for triple-negative breast cancer (TNBC). Here, we demonstrated that serum level of IL-12p40 monomer (p40) was much higher in breast cancer patients than healthy controls. On the other hand, levels of IL-12, IL-23 and p40 homodimer (p402) were lower in serum of breast cancer patients as compared to healthy controls. Similarly, human TNBC cells produced greater level of p40 than p402. The level of p40 was also larger than p402 in serum of a patient-derived xenograft (PDX) mouse model. Accordingly, neutralization of p40 by p40 mAb induced death of human TNBC cells and tumor shrinkage in PDX mice. While investigating the mechanism, we found that neutralization of p40 led to upregulation of human CD4+IFNγ+ and CD8+IFNγ+ T cell populations, thereby increasing the level of human IFNγ and decreasing the level of human IL-10 in PDX mice. Finally, we demonstrated the infiltration of human cytotoxic T cells, switching of tumor-associated macrophage M2 (TAM2) to TAM1 and suppression of transforming growth factor β (TGFβ) in tumor tissues of p40 mAb-treated PDX mice. Our studies identify a possible new immunotherapy for TNBC in which p40 mAb inhibits tumor growth in PDX mice.


Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 5009
Author(s):  
Swetha Vasudevan ◽  
Ibukun A. Adejumobi ◽  
Heba Alkhatib ◽  
Sangita Roy Chowdhury ◽  
Shira Stefansky ◽  
...  

Triple-negative breast cancer (TNBC) is an aggressive subgroup of breast cancers which is treated mainly with chemotherapy and radiotherapy. Epidermal growth factor receptor (EGFR) was considered to be frequently expressed in TNBC, and therefore was suggested as a therapeutic target. However, clinical trials of EGFR inhibitors have failed. In this study, we examine the relationship between the patient-specific TNBC network structures and possible mechanisms of resistance to anti-EGFR therapy. Using an information-theoretical analysis of 747 breast tumors from the TCGA dataset, we resolved individualized protein network structures, namely patient-specific signaling signatures (PaSSS) for each tumor. Each PaSSS was characterized by a set of 1–4 altered protein–protein subnetworks. Thirty-one percent of TNBC PaSSSs were found to harbor EGFR as a part of the network and were predicted to benefit from anti-EGFR therapy as long as it is combined with anti-estrogen receptor (ER) therapy. Using a series of single-cell experiments, followed by in vivo support, we show that drug combinations which are not tailored accurately to each PaSSS may generate evolutionary pressure in malignancies leading to an expansion of the previously undetected or untargeted subpopulations, such as ER+ populations. This corresponds to the PaSSS-based predictions suggesting to incorporate anti-ER drugs in certain anti-TNBC treatments. These findings highlight the need to tailor anti-TNBC targeted therapy to each PaSSS to prevent diverse evolutions of TNBC tumors and drug resistance development.


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