scholarly journals The challenges of modeling hormone receptor-positive breast cancer in mice

2018 ◽  
Vol 25 (5) ◽  
pp. R319-R330 ◽  
Author(s):  
Berna C Özdemir ◽  
George Sflomos ◽  
Cathrin Brisken
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Hormonal Regulation ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Endocrine Resistance ◽  
Xenograft Model ◽  
Genetically Engineered ◽  
Preclinical Research

Estrogen receptor-positive (ER+) tumors account for 70–80% of all breast cancer (BC) cases and are characterized by estrogen dependency for their growth. Endocrine therapies using estrogen receptor antagonists or aromatase inhibitors represent a key component of the standard of care for these tumors. The occurrence of de novo or acquired resistance to estrogen withdrawal represents an important clinical problem, impacting on patient survival. In addition, despite an initially favorable outcome, a part of ER+ BC patients present with disease recurrence locally or at distant sites years or even decades after apparent remission. In vivo models that closely mimic human disease are urgently needed to study the biology of these tumors, investigate the molecular mechanisms underlying endocrine resistance and identify patients at risk of recurrence. Despite the similarities in the overall hormonal regulation of mammary gland development between mice and humans, the majority of the mammary carcinomas occurring in genetically engineered mouse models (GEMMs) are ER negative and most xenograft models are based on few ER+ cancer cell lines. We recently showed that the microenvironment is critical for ER+ cancer cells and discuss in this review the potential of intraductal xenograft model for basic and preclinical research.

scholarly journals Molecular Mechanisms of Endocrine Resistance in Estrogen-Positive Breast Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Esmael Besufikad Belachew ◽  
Dareskedar Tsehay Sewasew
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Endocrine Resistance ◽  
Therapeutic Modality ◽  
Breast Cancers ◽  
Estrogen Receptor Positive ◽  
Positive Breast Cancer

The estrogen receptor is a vital receptor for therapeutic targets in estrogen receptor-positive breast cancer. The main strategy for the treatment of estrogen receptor-positive breast cancers is blocking the estrogen action on estrogen receptors by endocrine therapy but this can be restricted via endocrine resistance. Endocrine resistance occurs due to both de novo and acquired resistance. This review focuses on the mechanisms of the ligand-dependent and ligand-independent pathways and other coregulators, which are responsible for endocrine resistance. It concludes that combinatorial drugs that target different signaling pathways and coregulatory proteins together with endocrine therapy could be a novel therapeutic modality to stop endocrine resistance.

scholarly journals SMC1A promotes tumor growth in breast cancer by activation of the AKT/FOXM1/STMN1 Signaling Pathway

2021 ◽  
Author(s):  
kaichun li ◽  
Ping Dai ◽  
Lin Xue ◽  
Long Liu ◽  
Shiyu Cheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Molecular Mechanisms ◽  
Xenograft Model ◽  
Cell Cycle Checkpoints ◽  
Biological Functions ◽  
Tumor Tissues ◽  
Subcutaneous Xenograft ◽  
Novel Target

Abstract Background SMC1A (Structural maintenance of chromosomes 1) is overexpressed in various cancers and acts as an oncogene which has been implicated in critical biological functions (cell-cycle checkpoints regulation, cell division, and DNA repair). However, the mechanism and role of SMC1A in breast cancer are poorly understood. Methods TCGA database was utilized to explore the expression of SMC1A and the relationship between SMC1A and FOXM1 and STMN1. Subsequently, short hairpin RNA (shRNA) targeting SMC1A was used to examined the biological functions of it in MDA-MB-231 and MDA-MB-468 cells. Finally, subcutaneous xenograft model to verify the roles of SMC1A in vivo. Results In the present study, we demonstrated that SMC1A was significantly increased in breast cancer (BC) via TCGA database. Then loss and gain of function studies revealed that SMC1A contributed to BC cell survival, apoptosis, and invasion. Interestingly, we found that SMC1A triggered the AKT/FOXM1 cascade, which promoted BC cell proliferation. Furthermore, overexpression of FOXM1 abolished the inhibition of cell growth induced by SMC1A silencing in vitro. Clinically, the expression of SMC1A in BC tumor tissues is positively correlated with the expression of FOXM1. Conclusion Taken together, our findings not only enhanced our understanding of molecular mechanisms of SMC1A in BC, but also might provide a novel target for the development of therapeutic strategies.

scholarly journals The Dysregulated Expression of KCNQ1OT1 and Its Interaction with Downstream Factors miR-145/CCNE2 in Breast Cancer Cells

2018 ◽  
Vol 49 (2) ◽  
pp. 432-446 ◽  
Author(s):  
Weiliang Feng ◽  
Chen Wang ◽  
Chenlu Liang ◽  
Hongjian Yang ◽  
Daobao Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Cancer Biology ◽  
Molecular Mechanisms ◽  
Xenograft Model ◽  
The Cancer Genome Atlas ◽  
Tumor Xenograft ◽  
Luciferase Reporter ◽  
Migration And Invasion

Background/Aims: Next-generation sequencing (NGS) has revealed abundant long noncoding RNAs (lncRNAs) that have been characterized as critical components of cancer biology in humans. The present study aims to investigate the role of the lncRNA KCNQ1OT1 in breast cancer (BRCA) as well as the underlying molecular mechanisms and functions of KCNQ1OT1 involved in the progression of BRCA. Methods: The Cancer Genome Atlas (TCGA) and StarBase v2.0 were used to obtain the required gene data. Dual luciferase reporter gene assays were conducted to verify the relevant intermolecular target relationships. QRT-PCR and Western blot were performed to measure the expression levels of different molecules. Cell proliferation was detected by using the MTT and colony formation assays, while cell migration and invasion were examined by transwell assay. Variations in cell apoptosis and cell cycle were determined through flow cytometry. A tumor xenograft model was applied to assess tumor growth in vivo. Results: KCNQ1OT1 was found to be remarkably highly expressed in BRCA tissues and cells. KCNQ1OT1 modulated CCNE2 through sponging miR-145 in BRCA. KCNQ1OT1 promoted tumor growth in vivo by regulating miR-145/CCNE2. Conclusion: The KCNQ1OT1/miR-145/CCNE2 axis plays a critical regulatory role in BRCA, potentially giving rise to BRCA tumorigenesis and progression. These findings provide valuable evidence for improving the diagnosis and treatment of BRCA in the future.

scholarly journals SETD5 Binding to EP300/HIF1α is Required for Glycolysis in Breast Cancer Stem-Like Cells

2020 ◽  
Author(s):  
Zhaoting Yang ◽  
Huazi Li ◽  
Chengye Zhang ◽  
Nan Che ◽  
Ying Feng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Lactate Production ◽  
Xenograft Model ◽  
Regulatory Function ◽  
Mechanistic Study ◽  
The Impact

Abstract BackgroundGlycolysis plays a pivotal role in breast cancer stem-like cell reprogramming. The SET-domain containing 5 (SETD5) is a previously uncharacterized member of the histone lysine methyltransferase family. Yet, the molecular mechanisms underlying the promotion of stem-like and glycolysis activation traits of SETD5 have not been elucidated.MethodsBasing on public datasets, we explored clinicopathological and survival analysis of SETD5 on breast cancer (BC) patients. Spheroid formation, transfection experiments and measurement of glucose uptake and lactate production analyzed the regulatory function of SETD5 on glycolysis in breast cancer stem-like cells (BCSC). The impact of SETD5 on tumor growth was studied in a murine xenograft model. Immunohistochemistry, immunofluorescence, western blot, preparation of cytoplasmic and nuclear extracts and co-immunoprecipitation were used to determine the molecular mechanisms of SETD5 in cancer cell glycolysis.ResultsOur data displayed that overexpression of SETD5 in BC tissues is positively associated with progression. SETD5 overexpression is associated with poor post-progression survival in BC patients. SETD5 expression was enriched in spheroid cells. Downregulation of SETD5 significantly decreased BCSC properties and glycolysis in vitro and in vivo. Interestingly, SETD5 and glycolytic enzymes were accumulated in the central hypoxic regions of subcutaneous tumor tissues. Our mechanistic study found that SETD5 binding to EP300/hypoxia-inducible factor 1α (HIF1α) and work as an upstream effector. SETD5 knockdown reduced the expression of HIF1α, hexokinase-2, and 6-phosphofructo-2-kinase in the nucleus after treatment with cobalt chloride (CoCl2), a chemical hypoxia mimetic agent, which activates HIF1α to accumulate in the nucleus. ConclusionSETD5 is required for glycolysis in BCSCs through binding to EP300/HIF1α and could be a potential therapeutic target for BC patients.

scholarly journals Edelfosine nanoemulsions inhibit tumor growth of triple negative breast cancer in zebrafish xenograft model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia M. Saraiva ◽  
Carlha Gutiérrez-Lovera ◽  
Jeannette Martínez-Val ◽  
Sainza Lores ◽  
Belén L. Bouzo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Xenograft Model ◽  
Skin Barrier ◽  
Zebrafish Embryos ◽  
Biorelevant Media

AbstractTriple negative breast cancer (TNBC) is known for being very aggressive, heterogeneous and highly metastatic. The standard of care treatment is still chemotherapy, with adjacent toxicity and low efficacy, highlighting the need for alternative and more effective therapeutic strategies. Edelfosine, an alkyl-lysophospholipid, has proved to be a promising therapy for several cancer types, upon delivery in lipid nanoparticles. Therefore, the objective of this work was to explore the potential of edelfosine for the treatment of TNBC. Edelfosine nanoemulsions (ET-NEs) composed by edelfosine, Miglyol 812 and phosphatidylcholine as excipients, due to their good safety profile, presented an average size of about 120 nm and a neutral zeta potential, and were stable in biorelevant media. The ability of ET-NEs to interrupt tumor growth in TNBC was demonstrated both in vitro, using a highly aggressive and invasive TNBC cell line, and in vivo, using zebrafish embryos. Importantly, ET-NEs were able to penetrate through the skin barrier of MDA-MB 231 xenografted zebrafish embryos, into the yolk sac, leading to an effective decrease of highly aggressive and invasive tumoral cells’ proliferation. Altogether the results demonstrate the potential of ET-NEs for the development of new therapeutic approaches for TNBC.

scholarly journals A novel humanized Frizzled-7-targeting antibody enhances antitumor effects of Bevacizumab against triple-negative breast cancer via blocking Wnt/β-catenin signaling pathway

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Wei Xie ◽  
Huijie Zhao ◽  
Fengxian Wang ◽  
Yiyun Wang ◽  
Yuan He ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Molecular Mechanisms ◽  
Near Infrared ◽  
Triple Negative ◽  
Vasculogenic Mimicry ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Antitumor Effects ◽  
Mouse Xenograft Model

Abstract Background Anti-angiogenic therapy has been widely applied to the clinical treatment of malignant tumors. However, the efficacy of such treatments has been called into question, especially in triple-negative breast cancer (TNBC). Bevacizumab, the first anti-angiogenic agent approved by FDA, actually increases invasive and metastatic properties of TNBC cells, resulting from the activation of Wnt/β-catenin signaling in response to hypoxia. As a critical receptor of Wnt/β-catenin signaling, Frizzled-7 (Fzd7) is aberrantly expressed in TNBC, indicating Fzd7 a potential target for developing drugs to be combined with anti-angiogenic agents. Methods Hybridoma technique and antibody humanization technique were utilized to generate a Fzd7-targeting antibody (SHH002-hu1). Biolayer interferometry (BLI) assay and near infrared (NIR) imaging were conducted to detect the affinity and targeting ability of SHH002-hu1. Next, whether SHH002-hu1 could suppress the invasion and migration of TNBC cells induced by Bevacizumab were validated, and the underlying molecular mechanisms were elucidated by luciferase reporter and western blot assays. The nude-mice transplanted TNBC models were established to assess the anti-TNBC activities of SHH002-hu1 when combined with Bevacizumab. Then, the effects on putative TNBC stem-like cells and Wnt/β-catenin signaling were evaluated by immunofluorescence (IF). Further, the tumor-initiating and self-renew capacity of TNBC cells were studied by secondary nude mouse xenograft model and sphere formation assay. In addition, the effects of SHH002-hu1 on the adaptation of TNBC cells to hypoxia were evaluated by the detection of vasculogenic mimicry (VM) and hypoxia-inducible factor-1α (HIF-1α) transcriptional activity. Results The novel humanized antibody targeting Fzd7 (SHH002-hu1) exhibited extremely high affinity with Fzd7, and specifically targeted to Fzd7+ cells and tumor tissues. SHH002-hu1 repressed invasion, migration and epithelial-mesenchymal cell transformation (EMT) of TNBC cells induced by Bevacizumab through abating Wnt/β-catenin signaling. SHH002-hu1 significantly enhanced the capacity of Bevacizumab to inhibit the growth of TNBC via reducing the subpopulation of putative TNBC stem-like cells, further attenuating Bevacizumab-enhanced tumor-initiating and self-renew capacity of TNBC cells. Moreover, SHH002-hu1 effectively restrained the adaptation of TNBC cells to hypoxia via disrupting Wnt/β-catenin signaling. Conclusion SHH002-hu1 significantly enhances the anti-TNBC capacity of Bevacizumab, and shows the potential of preventing TNBC recurrence, suggesting SHH002-hu1 a good candidate for the synergistic therapy together with Bevacizumab.

scholarly journals The Emerging Role of Extracellular Vesicles in Endocrine Resistant Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1160
Author(s):  
Giusi La Camera ◽  
Luca Gelsomino ◽  
Amanda Caruso ◽  
Salvatore Panza ◽  
Ines Barone ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endocrine Therapy ◽  
Extracellular Vesicles ◽  
Molecular Mechanisms ◽  
Endocrine Resistance ◽  
Disease Recurrence ◽  
Estrogen Receptor Α ◽  
Research Area ◽  
Tumor Evolution

Breast cancer is the most common solid malignancy diagnosed in females worldwide, and approximately 70% of these tumors express estrogen receptor α (ERα), the main biomarker of endocrine therapy. Unfortunately, despite the use of long-term anti-hormone adjuvant treatment, which has significantly reduced patient mortality, resistance to the endocrine treatments often develops, leading to disease recurrence and limiting clinical benefits. Emerging evidence indicates that extracellular vesicles (EVs), nanosized particles that are released by all cell types and responsible for local and systemic intercellular communications, might represent a newly identified mechanism underlying endocrine resistance. Unraveling the role of EVs, released by transformed cells during the tumor evolution under endocrine therapy, is still an open question in the cancer research area and the molecular mechanisms involved should be better defined to discover alternative therapeutic approaches to overcome resistance. In this review, we will provide an overview of recent findings on the involvement of EVs in sustaining hormonal resistance in breast cancer and discuss opportunities for their potential use as biomarkers to monitor the therapeutic response and disease progression.

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