scholarly journals 4543 Glucocorticoid Receptors are essential effectors of TGFβ signaling in Triple Negative Breast Cancer

2020 ◽  
Vol 4 (s1) ◽  
pp. 7-8
Author(s):  
Carlos Jesus Perez Kerkvliet ◽  
Amy R Dwyer ◽  
Caroline Diep ◽  
Robert Oakley ◽  
Christopher Liddle ◽  
...  

OBJECTIVES/GOALS: The glucocorticoid receptor (GR) is a ubiquitous steroid hormone receptor that is emerging as a mediator of breast cancer metastasis. We aim to better understand the biology associated with phospho-GR species in TNBC and their contribution to tumor progression. METHODS/STUDY POPULATION: To better understand how p-S134 GR may impact TNBC cell biology, we probed GR regulation by soluble factors that are rich within the tumor microenvironment (TME), such as TGFβ. TNBC cells harboring endogenous wild-type or S134A-GR species were created by CRISPR/Cas knock-in and subjected to in vitro assays of advanced cancer behavior. RNA-Seq was employed to identify pS134-GR target genes that are uniquely regulated by TGFβ in the absence of exogenously added GR ligands. Direct regulation of selected TGFβ-induced pS134-GR target genes was validated accordingly. Bioinformatics tools were used to probe publicly available TNBC patient data sets for expression of a pS134-GR 24-gene signature. RESULTS/ANTICIPATED RESULTS: In the absence of GR ligands, GR is transcriptionally activated via p38-MAPK-dependent phosphorylation of Ser134 upon exposure of TNBC cells to TME-derived agents (TGFβ, HGF). The ligand-independent pS134-GR transcriptome primarily encompasses gene sets associated with TNBC cell survival and migration/invasion. Accordingly, pS134-GR was essential for TGFβ-induced TNBC cell migration, anchorage-independent growth in soft-agar, and tumorsphere formation, an in vitro readout of breast cancer stemness properties. Finally, a 24-gene pSer134-GR-dependent signature induced by TGFβ1 predicts shortened survival in breast cancer. We expect to find similar results using an in-house tissue microarray. DISCUSSION/SIGNIFICANCE OF IMPACT: Phospho-S134-GR is a critical downstream mediator of p38 MAPK signaling and TNBC migration, survival, and stemness properties. Our studies define GR as a required effector of TGFβ1 signaling and nominate pS134-GR as a biomarker of elevated risk of breast cancer dissemination.

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3003
Author(s):  
Di Zhang ◽  
Sadahiro Iwabuchi ◽  
Tomohisa Baba ◽  
Shin-ichi Hashimoto ◽  
Naofumi Mukaida ◽  
...  

Patients with triple negative breast cancer (TNBC) is frequently complicated by bone metastasis, which deteriorates the life expectancy of this patient cohort. In order to develop a novel type of therapy for bone metastasis, we established 4T1.3 clone with a high capacity to metastasize to bone after orthotopic injection, from a murine TNBC cell line, 4T1.0. To elucidate the molecular mechanism underlying a high growth ability of 4T1.3 in a bone cavity, we searched for a novel candidate molecule with a focus on a transcription factor whose expression was selectively enhanced in a bone cavity. Comprehensive gene expression analysis detected enhanced Nfe2 mRNA expression in 4T1.3 grown in a bone cavity, compared with in vitro culture conditions. Moreover, Nfe2 gene transduction into 4T1.0 cells enhanced their capability to form intraosseous tumors. Moreover, Nfe2 shRNA treatment reduced tumor formation arising from intraosseous injection of 4T1.3 clone as well as another mouse TNBC-derived TS/A.3 clone with an augmented intraosseous tumor formation ability. Furthermore, NFE2 expression was associated with in vitro growth advantages of these TNBC cell lines under hypoxic condition, which mimics the bone microenvironment, as well as Wnt pathway activation. These observations suggest that NFE2 can potentially contribute to breast cancer cell survival in the bone microenvironment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elizabeth Garcia ◽  
Ismat Luna ◽  
Kaya L. Persad ◽  
Kate Agopsowicz ◽  
David A. Jay ◽  
...  

AbstractInvasive breast cancer (BrCa) is predicted to affect 1 in 9 women in a lifetime;1 in 32 will die from this disease. The most aggressive forms of BrCa, basal-like/triple-negative phenotype (TNBC), are challenging to treat and result in higher mortality due high number of metastatic cases. There is a paucity of options for TNBC treatment, which highlights the need for additional innovative treatment approaches. NIH-III mice were injected in the abdominal mammary fat pad with luciferase-expressing derivative of the human TNBC cell line, MDA-MB-231 cells. Animals were gavage-fed with nitrofen at the doses of 1, 3 or 6 mg/kg/alternate days. However, several structural properties/components of nitrofen raise concerns, including its high lipophilicity (cLogP of nearly 5) and a potential toxophore in the form of a nitroarene group. Therefore, we developed analogues of nitrofen which lack the nitro group and/or have replaced the diaryl ether linker with a diarylamine that could allow modulation of polarity. In vitro anti-invasiveness activity of nitrofen analogues were evaluated by quantitative determination of invasion of MDA-MB-231-Luciferase cells through Matrigel using a Boyden chamber. Our in vivo data show that nitrofen efficiently blocks TNBC tumor metastasis. In vitro data suggest that this is not due to cytotoxicity, but rather is due to impairment of invasive capacity of the cells. Further, using an in vitro model of EMT, we show that nitrofen interferes with the process of EMT and promotes mesenchymal to epithelial transformation. In addition, we show that three of the nitrofen analogues significantly reduced invasive potential of TNBC cells, which may, at least partially, be attributed to the analogues’ ability to promote mesenchymal to epithelial-like transformation of TNBC cells. Our study shows that nitrofen, and more importantly its analogues, are significantly effective in limiting the invasive potential of TNBC cell lines with minimal cytotoxic effect. Further, we demonstrate that nitrofen its analogues, are very effective in reversing mesenchymal phenotype to a more epithelial-like phenotype. This may be significant for the treatment of patients with mesenchymal-TNBC tumor subtype who are well known to exhibit high resistance to chemotherapy.


2019 ◽  
Author(s):  
Daniel P. Hollern ◽  
Matthew R. Swiatnicki ◽  
Jonathan P. Rennhack ◽  
Sean A. Misek ◽  
Brooke C. Matson ◽  
...  

ABSTRACTIn prior work we demonstrated that loss of E2F transcription factors inhibits metastasis. Here we address the mechanisms for this phenotype and identify the E2F regulated genes that coordinate tumor cell metastasis. Transcriptomic profiling of E2F1 knockout tumors identified a role for E2F1 as a master regulator of a suite of pro-metastatic genes, but also uncovered E2F1 target genes with an unknown role in pulmonary metastasis. High expression of one of these genes, Fgf13, is associated with early human breast cancer metastasis in a clinical dataset. Together these data led to the hypothesis that Fgf13 is critical for breast cancer metastasis, and that upregulation of Fgf13 may partially explain how E2F1 promotes breast cancer metastasis. To test this hypothesis we ablated Fgf13 via CRISPR. Deletion of Fgf13 in a MMTV-PyMT breast cancer cell line reduces the frequency of pulmonary metastasis. In addition, loss of Fgf13 reduced in vitro cell migration, suggesting that Fgf13 may be critical for tumor cells to invade out of and escape the primary tumor. The significance of this work is twofold: we have both uncovered genomic features by which E2F1 regulates metastasis and we have identified new pro-metastatic functions for the E2F1 target gene Fgf13.


Cancers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 292 ◽  
Author(s):  
Laura Bray ◽  
Constanze Secker ◽  
Berline Murekatete ◽  
Jana Sievers ◽  
Marcus Binner ◽  
...  

Bone is the most common site for breast-cancer invasion and metastasis, and it causes severe morbidity and mortality. A greater understanding of the mechanisms leading to bone-specific metastasis could improve therapeutic strategies and thus improve patient survival. While three-dimensional in vitro culture models provide valuable tools to investigate distinct heterocellular and environmental interactions, sophisticated organ-specific metastasis models are lacking. Previous models used to investigate breast-to-bone metastasis have relied on 2.5D or singular-scaffold methods, constraining the in situ mimicry of in vitro models. Glycosaminoglycan-based gels have demonstrated outstanding potential for tumor-engineering applications. Here, we developed advanced biphasic in vitro microenvironments that mimic breast-tumor tissue (MCF-7 and MDA-MB-231 in a hydrogel) spatially separated with a mineralized bone construct (human primary osteoblasts in a cryogel). These models allow distinct advantages over former models due to the ability to observe and manipulate cellular migration towards a bone construct. The gels allow for the binding of adhesion-mediating peptides and controlled release of signaling molecules. Moreover, mechanical and architectural properties can be tuned to manipulate cell function. These results demonstrate the utility of these biomimetic microenvironment models to investigate heterotypic cell–cell and cell–matrix communications in cancer migration to bone.


Biomaterials ◽  
2014 ◽  
Vol 35 (8) ◽  
pp. 2454-2461 ◽  
Author(s):  
Simone Bersini ◽  
Jessie S. Jeon ◽  
Gabriele Dubini ◽  
Chiara Arrigoni ◽  
Seok Chung ◽  
...  

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3345-3345
Author(s):  
Anargyros Xenocostas ◽  
Benjamin D Hedley ◽  
Jenny E Chu ◽  
D. George Ormond ◽  
Michel Beausoleil ◽  
...  

Abstract Abstract 3345 Background: Erythropoietin (EPO) is a key regulator of erythropoiesis, and has been shown to stimulate growth, maintain viability, and promote differentiation of red blood cell precursors. The EPO receptor (EPO-R) is expressed by erythroid cells and by several non-hematopoietic cell types including various neoplastic cells. Erythropoiesis-stimulating agents (ESAs) are used clinically for the treatment of chemotherapy-induced anemia. The results of some recent randomized clinical trials have reported an increased incidence in adverse events and reduced survival in ESA-treated metastatic breast cancer patients receiving chemotherapy, potentially related to EPO-induced cancer progression. These results have raised concerns over ESA treatment in metastatic cancer patients. However, very little pre-clinical data is available regarding the impact of EPO on breast cancer metastasis. The goal of the current study was therefore to determine if EPO can influence the malignant behavior of breast cancer cells and/or influence the metastatic process. Methods: MDA-MB-468, MDA-MB-231, MDA-MB-435, and 4T-1 breast cancer cell lines were treated with recombinant human EPO (rHuEPO; 10 U/ml) or control media and screened for EPO-R mRNA expression levels by RT-PCR, and for EPO-R protein expression by Western blot and flow cytometry. MDA-MB-231 (231) and MDA-MB-435 (435) cell lines were used for functional assays in vitro and in vivo. Untreated or rHuEPO treated cells were grown in 2D and 3D in vitro systems (standard tissue culture plates and 0.6% soft agar, respectively) to determine if rHuEPO influenced growth. In vitro cell survival was also assessed in response to treatment with rHuEPO in the presence or absence of paclitaxel chemotherapy (10mg/ml), radiation (10G), or hypoxic conditions (1% O2). Following mammary fat pad injection, in vivo effects of rHuEPO (300U/kg) alone or in combination with paclitaxel treatment (10mg/kg) were assessed in mouse models of tumorigenicity and spontaneous metastasis. Results: Expression analysis of EPO-R mRNA and protein revealed a large variation in levels across different cell lines. The majority of cell lines did not express cell surface EPO-R by flow cytometry, although two cell lines (231 and 435) did show weak expression of EPO-R mRNA, with only the 231 cell line showing EPO-R expression by Western blot. In vitro, a small protective effect from rHuEPO on radiation-treated 435 cells was seen (p<0.05); however, rHuEPO treatment alone or combined with chemotherapy or hypoxia did not cause a significant increase in cell survival relative to untreated controls cells. In contrast, in vivo studies demonstrated that rHuEPO increased the incidence and burden of lung metastases in immunocompromised mice injected with 231 or 435 cells and treated with paclitaxel relative to mice treated with paclitaxel alone (p<0.05). Conclusions: The lack of an in vitro effect of rHuEPO highlights the importance of in vivo studies to delineate the effects of EPO on the metastatic process. Our novel findings demonstrate that rHuEPO can reduce the efficacy of chemotherapy in the metastatic setting in vivo, and in some cases enhance the inherent metastatic growth potential of human breast cancer cells. This work was supported by funding from the London Regional Cancer Program and Janssen Ortho Canada Disclosures: Xenocostas: Janssen Ortho: Consultancy, Honoraria, Research Funding. Allan:Janssen Ortho: Research Funding.


2011 ◽  
Vol 10 ◽  
pp. CIN.S6631 ◽  
Author(s):  
Alan A. Dombkowski ◽  
Zakia Sultana ◽  
Douglas B. Craig ◽  
Hasan Jamil

Aberrant microRNA activity has been reported in many diseases, and studies often find numerous microRNAs concurrently dysregulated. Most target genes have binding sites for multiple microRNAs, and mounting evidence indicates that it is important to consider their combinatorial effect on target gene repression. A recent study associated the coincident loss of expression of six microRNAs with metastatic potential in breast cancer. Here, we used a new computational method, miR-AT!, to investigate combinatorial activity among this group of microRNAs. We found that the set of transcripts having multiple target sites for these microRNAs was significantly enriched with genes involved in cellular processes commonly perturbed in metastatic tumors: cell cycle regulation, cytoskeleton organization, and cell adhesion. Network analysis revealed numerous target genes upstream of cyclin D1 and c-Myc, indicating that the collective loss of the six microRNAs may have a focal effect on these two key regulatory nodes. A number of genes previously implicated in cancer metastasis are among the predicted combinatorial targets, including TGFB1, ARPC3, and RANKL. In summary, our analysis reveals extensive combinatorial interactions that have notable implications for their potential role in breast cancer metastasis and in therapeutic development.


2014 ◽  
Vol 13 (1) ◽  
pp. 12 ◽  
Author(s):  
Khaled Ghattass ◽  
Sally El-Sitt ◽  
Kazem Zibara ◽  
Saide Rayes ◽  
Makhluf J Haddadin ◽  
...  

2004 ◽  
Vol 24 (22) ◽  
pp. 9726-9735 ◽  
Author(s):  
Julie A. Nagle ◽  
Zhefu Ma ◽  
Maura A. Byrne ◽  
Morris F. White ◽  
Leslie M. Shaw

ABSTRACT The insulin receptor substrate (IRS) proteins are adaptor molecules that integrate signals generated by receptors that are implicated in human breast cancer. We investigated the specific contribution of IRS-2 to mammary tumor progression using transgenic mice that express the polyoma virus middle T antigen (PyV-MT) in the mammary gland and IRS-2-null (IRS-2−/−) mice. PyV-MT-induced tumor initiation and growth were similar in wild-type (WT) and IRS-2−/− mice. However, the latency and incidence of metastasis were significantly decreased in the absence of IRS-2 expression. The contribution of IRS-2 to metastasis is intrinsic to the tumor cells, because IRS-2−/− mammary tumor cells did not metastasize when grown orthotopically in the mammary fat pads of WT mice. WT and IRS-2−/− tumors contained similar numbers of mitotic cells, but IRS-2−/− tumors had a higher incidence of apoptosis than did WT tumors. In vitro, IRS-2−/− mammary tumor cells were less invasive and more apoptotic in response to growth factor deprivation than their WT counterparts. In contrast, IRS-1−/− tumor cells, which express only IRS-2, were highly invasive and were resistant to apoptotic stimuli. Collectively, our findings reveal an important contribution of IRS-2 to breast cancer metastasis.


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