1
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Ngwa VM, Edwards DN, Hwang Y, Karno B, Wang X, Yan C, Richmond A, Brantley-Sieders DM, Chen J. Loss of vascular endothelial glutaminase inhibits tumor growth and metastasis, and increases sensitivity to chemotherapy. Cancer Res Commun 2022; 2:694-705. [PMID: 36381236 PMCID: PMC9645801 DOI: 10.1158/2767-9764.crc-22-0048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/06/2022] [Accepted: 06/23/2022] [Indexed: 02/02/2023]
Abstract
Glutamine is the most abundant non-essential amino acid in blood stream; yet it's concentration in tumor interstitium is markedly lower than that in the serum, reflecting the huge demand of various cell types in tumor microenvironment for glutamine. While many studies have investigated glutamine metabolism in tumor epithelium and infiltrating immune cells, the role of glutamine metabolism in tumor blood vessels remains unknown. Here, we report that inducible genetic deletion of glutaminase (GLS) specifically in host endothelium, GLSECKO, impairs tumor growth and metastatic dissemination in vivo. Loss of GLS decreased tumor microvascular density, increased perivascular support cell coverage, improved perfusion, and reduced hypoxia in mammary tumors. Importantly, chemotherapeutic drug delivery and therapeutic efficacy were improved in tumor-bearing GLSECKO hosts or in combination with GLS inhibitor, CB839. Mechanistically, loss of GLS in tumor endothelium resulted in decreased leptin levels, and exogenous recombinant leptin rescued tumor growth defects in GLSECKO mice. Together, these data demonstrate that inhibition of endothelial glutamine metabolism normalizes tumor vessels, reducing tumor growth and metastatic spread, improving perfusion, and reducing hypoxia, and enhancing chemotherapeutic delivery. Thus, targeting glutamine metabolism in host vasculature may improve clinical outcome in patients with solid tumors.
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Affiliation(s)
- Verra M. Ngwa
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Deanna N. Edwards
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yoonha Hwang
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Breelyn Karno
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Xiaoyong Wang
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Chi Yan
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Ann Richmond
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
- Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dana M. Brantley-Sieders
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jin Chen
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee
- Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
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2
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Grewelle RE, Wilson KL, Brantley-Sieders DM. Abstract 262: Statistical Bliss: A novel framework for statistical assessment of drug synergy. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Combination therapy is a common feature of cancer treatment, aiming to maximize efficacy while minimizing toxicity and opportunities for acquired resistance. It is critical to assess which combinations achieve best effects. This requires rigorous, statistically sound methods of characterizing the relationships between drugs as synergistic, independent, or antagonistic. Current frameworks, including Bliss independence and Loewe additivity as implemented by the Chou-Talalay method, are not statistical and assess effects at discrete points rather than across the entirety of a dose-response curve, limiting their application. We aimed to create a comprehensive statistical framework applicable to dose-response curves of all forms and any number of drugs in combination. We developed a generalized definition of independent action to construct theorized dose-response curves of drugs in combination informed by empirically fitted dose-response curves for individual drugs. We derive uncertainty estimates for theorized curves, which are compared to empirical measurements of fixed- or variable-ratio drug combinations at all measured concentrations. Separately accounting for variability in technical and experimental replicates allows robust statistics at each experimental condition as well as globally across the range of conditions. As an example of its utility, we applied this model to a system of known synthetic lethality. We exposed BRCA-mutant (HCC1937) and wild-type (MDA-MB-231) triple-negative breast cancer cell lines to PARP inhibitor (PARPi) olaparib and RAD51 inhibitors (RAD51i) IBR2 or B02 singly and in variable-ratio combinations and evaluated cell viability at 96 hours post-treatment by MTT assay. We hypothesized that combination of RAD51i, producing a defect in homologous recombination, with olaparib in BRCA-WT cells would phenocopy the synthetic lethal effect of PARPi in BRCA-Mut cells and demonstrate synergy, whereas there would be no synergy in BRCA-Mut cells. HCC1937 cells demonstrated antagonism between olaparib and B02 (p < 0.001) or IBR2 (p < 0.001). MDA-MB-231 cells demonstrated significant synergy of olaparib and B02 (p < 0.001) or IBR2 (p < 0.001), consistent with our hypothesis. However, the interaction of olaparib and B02 was dose-dependent with synergy overall but antagonism at high concentrations. This shows that (1) measurements at single concentrations may be misleading and (2) our new method may guide optimal drug concentration selection. We also assessed a “sham” combination of B02 with itself in MDA-MB-231 cells and predictably detected neither synergy nor antagonism (p = 0.39). Not only do these data provide evidence for expanded use of PARPi alongside RAD51i in BRCA-WT cancers, they validate this statistical approach that offers a robust calculation of synergy or antagonism with broad applicability to any study of combination therapies, especially for high-throughput screening.
Citation Format: Richard E. Grewelle, Kalin L. Wilson, Dana M. Brantley-Sieders. Statistical Bliss: A novel framework for statistical assessment of drug synergy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 262.
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3
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Abstract
More than 25 years of research and preclinical validation have defined EphA2 receptor tyrosine kinase as a promising molecular target for clinical translation in cancer treatment. Molecular, genetic, biochemical, and pharmacological targeting strategies have been extensively tested in vitro and in vivo, and drugs like dasatinib, initially designed to target SRC family kinases, have been found to also target EphA2 activity. Other small molecules, therapeutic targeting antibodies, and peptide-drug conjugates are being tested, and more recently, approaches harnessing antitumor immunity against EphA2-expressing cancer cells have emerged as a promising strategy. This review will summarize preclinical studies supporting the oncogenic role of EphA2 in breast cancer, lung cancer, glioblastoma, and melanoma, while delineating the differing roles of canonical and noncanonical EphA2 signaling in each setting. This review also summarizes completed and ongoing clinical trials, highlighting the promise and challenges of targeting EphA2 in cancer.
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Affiliation(s)
- Kalin Wilson
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, TN, 37232, USA
| | - Eileen Shiuan
- Vanderbilt University School of Medicine, Vanderbilt University, Nashville, TN, 37232, USA
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
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4
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Song W, Kim LC, Han W, Hou Y, Edwards DN, Wang S, Blackwell TS, Cheng F, Brantley-Sieders DM, Chen J. Phosphorylation of PLCγ1 by EphA2 Receptor Tyrosine Kinase Promotes Tumor Growth in Lung Cancer. Mol Cancer Res 2020; 18:1735-1743. [PMID: 32753469 PMCID: PMC7641970 DOI: 10.1158/1541-7786.mcr-20-0075] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 07/07/2020] [Accepted: 07/20/2020] [Indexed: 12/23/2022]
Abstract
EphA2 receptor tyrosine kinase (RTK) is often expressed at high levels in cancer and has been shown to regulate tumor growth and metastasis across multiple tumor types, including non-small cell lung cancer. A number of signaling pathways downstream of EphA2 RTK have been identified; however, mechanisms of EphA2 proximal downstream signals are less well characterized. In this study, we used a yeast-two-hybrid screen to identify phospholipase C gamma 1 (PLCγ1) as a novel EphA2 interactor. EphA2 interacts with PLCγ1 and the kinase activity of EphA2 was required for phosphorylation of PLCγ1. In human lung cancer cells, genetic or pharmacologic inhibition of EphA2 decreased phosphorylation of PLCγ1 and loss of PLCγ1 inhibited tumor cell growth in vitro. Knockout of PLCγ1 by CRISPR-mediated genome editing also impaired tumor growth in a KrasG12D-p53-Lkb1 murine lung tumor model. Collectively, these data show that the EphA2-PLCγ1 signaling axis promotes tumor growth of lung cancer and provides rationale for disruption of this signaling axis as a potential therapeutic option. IMPLICATIONS: The EphA2-PLCG1 signaling axis promotes tumor growth of non-small cell lung cancer and can potentially be targeted as a therapeutic option.
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Affiliation(s)
- Wenqiang Song
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Laura C Kim
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Wei Han
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Yuan Hou
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Deanna N Edwards
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Shan Wang
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Timothy S Blackwell
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| | - Feixiong Cheng
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
- Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jin Chen
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
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5
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Werfel TA, Hicks DJ, Rahman B, Bendeman WE, Duvernay MT, Maeng JG, Hamm H, Lavieri RR, Joly MM, Pulley JM, Elion DL, Brantley-Sieders DM, Cook RS. Repurposing of a Thromboxane Receptor Inhibitor Based on a Novel Role in Metastasis Identified by Phenome-Wide Association Study. Mol Cancer Ther 2020; 19:2454-2464. [PMID: 33033174 DOI: 10.1158/1535-7163.mct-19-1106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/03/2020] [Accepted: 09/15/2020] [Indexed: 11/16/2022]
Abstract
Although new drug discoveries are revolutionizing cancer treatments, repurposing existing drugs would accelerate the timeline and lower the cost for bringing treatments to cancer patients. Our goal was to repurpose CPI211, a potent and selective antagonist of the thromboxane A2-prostanoid receptor (TPr), a G-protein-coupled receptor that regulates coagulation, blood pressure, and cardiovascular homeostasis. To identify potential new clinical indications for CPI211, we performed a phenome-wide association study (PheWAS) of the gene encoding TPr, TBXA2R, using robust deidentified health records and matched genomic data from more than 29,000 patients. Specifically, PheWAS was used to identify clinical manifestations correlating with a TBXA2R single-nucleotide polymorphism (rs200445019), which generates a T399A substitution within TPr that enhances TPr signaling. Previous studies have correlated 200445019 with chronic venous hypertension, which was recapitulated by this PheWAS analysis. Unexpectedly, PheWAS uncovered an rs200445019 correlation with cancer metastasis across several cancer types. When tested in several mouse models of metastasis, TPr inhibition using CPI211 potently blocked spontaneous metastasis from primary tumors, without affecting tumor cell proliferation, motility, or tumor growth. Further, metastasis following intravenous tumor cell delivery was blocked in mice treated with CPI211. Interestingly, TPr signaling in vascular endothelial cells induced VE-cadherin internalization, diminished endothelial barrier function, and enhanced transendothelial migration by tumor cells, phenotypes that were decreased by CPI211. These studies provide evidence that TPr signaling promotes cancer metastasis, supporting the study of TPr inhibitors as antimetastatic agents and highlighting the use of PheWAS as an approach to accelerate drug repurposing.
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Affiliation(s)
- Thomas A Werfel
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee.,Department of Chemical Engineering, University of Mississippi, Oxford, Mississippi
| | - Donna J Hicks
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Bushra Rahman
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Wendy E Bendeman
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Matthew T Duvernay
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jae G Maeng
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Heidi Hamm
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Robert R Lavieri
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Meghan M Joly
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jill M Pulley
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, Tennessee
| | - David L Elion
- Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Dana M Brantley-Sieders
- Breast Cancer Research Program, Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rebecca S Cook
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee. .,Program in Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee.,Breast Cancer Research Program, Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Biomedical Engineering, Vanderbilt University School of Engineering, Nashville, Tennessee
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6
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Brantley-Sieders DM. Abstract 5017: EphA2 is a clinically relevant target for breast cancer bone metastatic disease. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-5017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
While advances in molecular targeted therapies have increased survival for breast cancer patients, outcomes for patients with metastatic disease remain poor. EphA2 receptor tyrosine kinase (RTK) is highly expressed in breast tumor cells across multiple molecular subtypes and correlates with poor patient prognosis. As metastasis of breast cancer to bone is a major cause of morbidity and mortality in patients, we investigated the role of EphA2 in this clinically relevant phenomenon. Analysis of human patient gene expression datasets and human breast-to-bone metastasis samples revealed high level ephA2 expression in bone lesions relative to other sites of metastatic dissemination, and EphA2 positive staining on breast tumor cells in bone metastatic lesions, respectively. EphA2 loss of function in tumor cells reduced tumor-induced osteolysis in two independent intratibial tumor engraftment models (4T1 and MDA-MB-231) as well as in an intracardiac experimental metastasis model (MDA-MB-231) in vivo. We observed a significant reduction in osteoclasts in animals harboring EphA2 loss of function tumors relative to control tumors. Further in vitro analyses revealed that blocking EphA2 function resulted in defective precursor maturation into functional osteoclasts through an interleukin-6 (IL-6) dependent mechanism. Pharmacologic inhibition of EphA2 decreased breast tumor induced osteolytic disease severity in vivo. Together, these data provide pre-clinical validation of EphA2 as a clinically relevant molecular target for breast cancer bone metastatic, osteolytic disease, warranting further investigation of molecular mechanisms that link EphA2 to tumor-induced osteolysis and eventual clinical development.
Citation Format: Dana M. Brantley-Sieders. EphA2 is a clinically relevant target for breast cancer bone metastatic disease [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5017.
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7
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Wilson KL, Brantley-Sieders DM. Abstract 4139: Investigations of drug synergy reveal promising efficacy of EphA2 inhibition combined with CDK inhibition in triple-negative breast cancer. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-4139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Triple-negative breast cancer (TNBC) is an aggressive malignancy with poor prognosis relative to other breast cancers. Due to its lack of expression of commonly targeted cell surface markers and hormone receptors, there is a dearth of precision treatment options for this malignancy, with chemotherapy and radiation therapy remaining the major mainstays of care. Our group has previously reported that the receptor tyrosine kinase EphA2 is enriched in the basal-like/triple-negative breast cancer subtype and that this expression is associated with reduced recurrence-free survival. Furthermore, genetic knockdown or inhibition of EphA2 with the small molecule ALW-II-41-27 (ALW) reduces cancer cell growth in vitro and in vivo. In these studies, we sought to investigate whether the antitumor properties of ALW can be augmented by addition of other compounds to further reduce cancer cell growth and induce apoptosis. To this end, TNBC lines MDA-MB-231, BT-549, HCC1395, and HCC1187 were seeded in 96-well plates and exposed to ALW alone or in combination with chemotherapeutic agents doxorubicin and paclitaxel, CDK inhibitor SCH-727965, and MCL-1 inhibitor S63845 and cell viability assessed by MTT assay at 48 hours. While there was no significant reduction in viability for cells treated with ALW plus chemotherapy and no consistent improvement with addition of S63845 across cell lines, the combination of ALW with SCH-727965 performed significantly better than either drug alone (p < 0.05) in HCC1395 and BT-549 cells. To evaluate drug synergy, cells of all lines above were exposed to variable concentrations of SCH-727965, ALW, and the combination in a fixed ratio of their respective IC50 values to generate dose response curves, and these data analyzed via CompuSyn software. Combination indices (CI) were <1 for the majority of conditions across all cell lines, supporting synergistic interaction. Effects were most pronounced in HCC1395 cells with average CI 0.82. Furthermore, TUNEL assays show that addition of SCH-727965 to ALW significantly increases the induction of apoptosis by HCC1395 and HCC1187 cells. These preclinical studies demonstrate that combination of ALW and SCH-727965 potently reduces TNBC cell growth and promotes cell death, representing promising early data on the effects of EphA2 inhibition as part of a combination targeted therapeutic approach for triple-negative breast cancer.
Citation Format: Kalin L. Wilson, Dana M. Brantley-Sieders. Investigations of drug synergy reveal promising efficacy of EphA2 inhibition combined with CDK inhibition in triple-negative breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4139.
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8
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Wang S, Raybuck A, Shiuan E, Cho SH, Wang Q, Brantley-Sieders DM, Edwards D, Allaman MM, Nathan J, Wilson KT, DeNardo D, Zhang S, Cook R, Boothby M, Chen J. Selective inhibition of mTORC1 in tumor vessels increases antitumor immunity. JCI Insight 2020; 5:139237. [PMID: 32759497 PMCID: PMC7455083 DOI: 10.1172/jci.insight.139237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
A tumor blood vessel is a key regulator of tissue perfusion, immune cell trafficking, cancer metastasis, and therapeutic responsiveness. mTORC1 is a signaling node downstream of multiple angiogenic factors in the endothelium. However, mTORC1 inhibitors have limited efficacy in most solid tumors, in part due to inhibition of immune function at high doses used in oncology patients and compensatory PI3K signaling triggered by mTORC1 inhibition in tumor cells. Here we show that low-dose RAD001/everolimus, an mTORC1 inhibitor, selectively targets mTORC1 signaling in endothelial cells (ECs) without affecting tumor cells or immune cells, resulting in tumor vessel normalization and increased antitumor immunity. Notably, this phenotype was recapitulated upon targeted inducible gene ablation of the mTORC1 component Raptor in tumor ECs (RaptorECKO). Tumors grown in RaptorECKO mice displayed a robust increase in tumor-infiltrating lymphocytes due to GM-CSF-mediated activation of CD103+ dendritic cells and displayed decreased tumor growth and metastasis. GM-CSF neutralization restored tumor growth and metastasis, as did T cell depletion. Importantly, analyses of human tumor data sets support our animal studies. Collectively, these findings demonstrate that endothelial mTORC1 is an actionable target for tumor vessel normalization, which could be leveraged to enhance antitumor immune therapies.
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Affiliation(s)
- Shan Wang
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Division of Rheumatology and Immunology and
| | - Ariel Raybuck
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Eileen Shiuan
- Program in Cancer Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Sung Hoon Cho
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Qingfei Wang
- Department of Biological Sciences, Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana, USA
| | | | | | - Margaret M Allaman
- Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - James Nathan
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Keith T Wilson
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Program in Cancer Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt-Ingram Cancer Center and.,Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - David DeNardo
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Siyuan Zhang
- Department of Biological Sciences, Harper Cancer Research Institute, University of Notre Dame, South Bend, Indiana, USA
| | - Rebecca Cook
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Department of Cell and Developmental Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Mark Boothby
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.,Program in Cancer Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt-Ingram Cancer Center and
| | - Jin Chen
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Division of Rheumatology and Immunology and.,Program in Cancer Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt-Ingram Cancer Center and.,Department of Cell and Developmental Biology, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
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9
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Abstract
Background: The conventional dogma of treating cancer by focusing on the elimination of tumor cells has been recently refined to include consideration of the tumor microenvironment, which includes host stromal cells. Ephrin-A1, a cell surface protein involved in adhesion and migration, has been shown to be tumor suppressive in the context of the cancer cell. However, its role in the host has not been fully investigated. Here, we examine how ephrin-A1 host deficiency affects cancer growth and metastasis in a murine model of breast cancer. Methods: 4T1 cells were orthotopically implanted into the mammary fat pads or injected into the tail veins of ephrin-A1 wild-type (
Efna1+/+), heterozygous (
Efna1+/-), or knockout (
Efna1-/-) mice. Tumor growth, lung metastasis, and tumor recurrence after surgical resection were measured. Flow cytometry and immunohistochemistry (IHC) were used to analyze various cell populations in primary tumors and tumor-bearing lungs. Results: While primary tumor growth did not differ between
Efna1+/+,
Efna1+/-, and
Efna1-/- mice, lung metastasis and primary tumor recurrence were significantly decreased in knockout mice.
Efna1-/- mice had reduced lung colonization of 4T1 cells compared to
Efna1+/+ littermate controls as early as 24 hours after tail vein injection. Furthermore, established lung lesions in
Efna1-/- mice had reduced proliferation compared to those in
Efna1+/+ controls. Conclusions: Our studies demonstrate that host deficiency of ephrin-A1 does not impact primary tumor growth but does affect metastasis by providing a less favorable metastatic niche for cancer cell colonization and growth. Elucidating the mechanisms by which host ephrin-A1 impacts cancer relapse and metastasis may shed new light on novel therapeutic strategies.
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Affiliation(s)
- Eileen Shiuan
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, 37232, USA.,Medical Scientist Training Program, Vanderbilt University, Nashville, TN, 37232, USA
| | - Ashwin Inala
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Shan Wang
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Wenqiang Song
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | | | - Jin Chen
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
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10
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Abstract
Background: The conventional dogma of treating cancer by focusing on the elimination of tumor cells has been recently refined to include consideration of the tumor microenvironment, which includes host stromal cells. Ephrin-A1, a cell surface protein involved in adhesion and migration, has been shown to be tumor suppressive in the context of the cancer cell. However, its role in the host has not been fully investigated. Here, we examine how ephrin-A1 host deficiency affects cancer growth and metastasis in a murine model of breast cancer. Methods: 4T1 cells were orthotopically implanted into the mammary fat pads or injected into the tail veins of ephrin-A1 wild-type ( Efna1 +/+), heterozygous ( Efna1 +/-), or knockout ( Efna1 -/-) mice. Tumor growth, lung metastasis, and tumor recurrence after surgical resection were measured. Flow cytometry and immunohistochemistry (IHC) were used to analyze various cell populations in primary tumors and tumor-bearing lungs. Results: While primary tumor growth did not differ between Efna1 +/+, Efna1 +/-, and Efna1 -/- mice, lung metastasis and primary tumor recurrence were significantly decreased in knockout mice. Efna1 -/- mice had reduced lung colonization of 4T1 cells compared to Efna1 +/+ littermate controls as early as 24 hours after tail vein injection. Furthermore, established lung lesions in Efna1 -/- mice had reduced proliferation compared to those in Efna1 +/+ controls. Conclusions: Our studies demonstrate that host deficiency of ephrin-A1 does not impact primary tumor growth but does affect metastasis by providing a less favorable metastatic niche for cancer cell colonization and growth. Elucidating the mechanisms by which host ephrin-A1 impacts cancer relapse and metastasis may shed new light on novel therapeutic strategies.
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Affiliation(s)
- Eileen Shiuan
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, 37232, USA.,Medical Scientist Training Program, Vanderbilt University, Nashville, TN, 37232, USA
| | - Ashwin Inala
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Shan Wang
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Wenqiang Song
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | | | - Jin Chen
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, 37212, USA.,Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
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11
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Edwards DN, Ngwa VM, Wang S, Shiuan E, Brantley-Sieders DM, Kim LC, Reynolds AB, Chen J. Abstract P2-02-02: The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p2-02-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells, and upstream regulatory signaling pathways may represent a novel mechanism for targeted therapies in glutamine-addicted breast tumors such as Her2-overexpressing and triple-negative breast cancers (TNBC). We have found that the receptor tyrosine kinase EphA2 activated the transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS, respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain the consensus sequence of the TEAD family of transcription factors that are closely associated with YAP/TAZ and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ, as well as that of GLS and SLC1A5. Although high expression of EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in breast cancer and identify potential therapeutic targets in patients.
Citation Format: Edwards DN, Ngwa VM, Wang S, Shiuan E, Brantley-Sieders DM, Kim LC, Reynolds AB, Chen J. The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-02.
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Affiliation(s)
- DN Edwards
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - VM Ngwa
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - S Wang
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - E Shiuan
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - DM Brantley-Sieders
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - LC Kim
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - AB Reynolds
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
| | - J Chen
- Vanderbilt University Medical Center, Nashville, TN; Vanderbilt University, Nashville, TN
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12
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Werfel TA, Wang S, Jackson MA, Kavanaugh TE, Joly MM, Lee LH, Hicks DJ, Sanchez V, Ericsson PG, Kilchrist KV, Dimobi SC, Sarett SM, Brantley-Sieders DM, Cook RS, Duvall CL. Selective mTORC2 Inhibitor Therapeutically Blocks Breast Cancer Cell Growth and Survival. Cancer Res 2018; 78:1845-1858. [PMID: 29358172 DOI: 10.1158/0008-5472.can-17-2388] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/11/2017] [Accepted: 01/17/2018] [Indexed: 12/12/2022]
Abstract
Small-molecule inhibitors of the mTORC2 kinase (torkinibs) have shown efficacy in early clinical trials. However, the torkinibs under study also inhibit the other mTOR-containing complex mTORC1. While mTORC1/mTORC2 combined inhibition may be beneficial in cancer cells, recent reports describe compensatory cell survival upon mTORC1 inhibition due to loss of negative feedback on PI3K, increased autophagy, and increased macropinocytosis. Genetic models suggest that selective mTORC2 inhibition would be effective in breast cancers, but the lack of selective small-molecule inhibitors of mTORC2 have precluded testing of this hypothesis to date. Here we report the engineering of a nanoparticle-based RNAi therapeutic that can effectively silence the mTORC2 obligate cofactor Rictor. Nanoparticle-based Rictor ablation in HER2-amplified breast tumors was achieved following intratumoral and intravenous delivery, decreasing Akt phosphorylation and increasing tumor cell killing. Selective mTORC2 inhibition in vivo, combined with the HER2 inhibitor lapatinib, decreased the growth of HER2-amplified breast cancers to a greater extent than either agent alone, suggesting that mTORC2 promotes lapatinib resistance, but is overcome by mTORC2 inhibition. Importantly, selective mTORC2 inhibition was effective in a triple-negative breast cancer (TNBC) model, decreasing Akt phosphorylation and tumor growth, consistent with our findings that RICTOR mRNA correlates with worse outcome in patients with basal-like TNBC. Together, our results offer preclinical validation of a novel RNAi delivery platform for therapeutic gene ablation in breast cancer, and they show that mTORC2-selective targeting is feasible and efficacious in this disease setting.Significance: This study describes a nanomedicine to effectively inhibit the growth regulatory kinase mTORC2 in a preclinical model of breast cancer, targeting an important pathogenic enzyme in that setting that has been undruggable to date. Cancer Res; 78(7); 1845-58. ©2018 AACR.
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Affiliation(s)
- Thomas A Werfel
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Shan Wang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Meredith A Jackson
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Taylor E Kavanaugh
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Meghan Morrison Joly
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Linus H Lee
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Donna J Hicks
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Violeta Sanchez
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Paula Gonzalez Ericsson
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Kameron V Kilchrist
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Somtochukwu C Dimobi
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Samantha M Sarett
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Dana M Brantley-Sieders
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.,Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rebecca S Cook
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee. .,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee.,Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Craig L Duvall
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee.
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13
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Edwards DN, Ngwa VM, Wang S, Shiuan E, Brantley-Sieders DM, Kim LC, Reynolds AB, Chen J. The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ. Sci Signal 2017; 10:eaan4667. [PMID: 29208682 PMCID: PMC5819349 DOI: 10.1126/scisignal.aan4667] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells. We found that the receptor tyrosine kinase EphA2 activated the TEAD family transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of HER2-positive breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ substantially reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS, respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain TEAD binding sites and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ, as well as that of GLS and SLC1A5 Although high expression of EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered HER2-positive breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in HER2-positive breast cancer and identify potential therapeutic targets in patients.
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Affiliation(s)
- Deanna N Edwards
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Verra M Ngwa
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Shan Wang
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Eileen Shiuan
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
- Medical Scientist Training Program, Vanderbilt University, Nashville, TN 37232, USA
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Laura C Kim
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Albert B Reynolds
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Jin Chen
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN 37212, USA
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14
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Song W, Hwang Y, Youngblood VM, Cook RS, Balko JM, Chen J, Brantley-Sieders DM. Targeting EphA2 impairs cell cycle progression and growth of basal-like/triple-negative breast cancers. Oncogene 2017; 36:5620-5630. [PMID: 28581527 PMCID: PMC5629103 DOI: 10.1038/onc.2017.170] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/27/2017] [Accepted: 05/01/2017] [Indexed: 02/06/2023]
Abstract
Basal-like/triple-negative breast cancers (TNBCs) are among the most aggressive forms of breast cancer, and disproportionally affects young premenopausal women and women of African descent. Patients with TNBC suffer a poor prognosis due in part to a lack of molecularly targeted therapies, which represents a critical barrier for effective treatment. Here, we identify EphA2 receptor tyrosine kinase as a clinically relevant target for TNBC. EphA2 expression is enriched in the basal-like molecular subtype in human breast cancers. Loss of EphA2 function in both human and genetically engineered mouse models of TNBC reduced tumor growth in culture and in vivo. Mechanistically, targeting EphA2 impaired cell cycle progression through S-phase via downregulation of c-Myc and stabilization of the cyclin-dependent kinase inhibitor p27/KIP1. A small molecule kinase inhibitor of EphA2 effectively suppressed tumor cell growth in vivo, including TNBC patient-derived xenografts. Thus, our data identify EphA2 as a novel molecular target for TNBC.
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Affiliation(s)
- W Song
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Y Hwang
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - V M Youngblood
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - R S Cook
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - J M Balko
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - J Chen
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Cellular and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - D M Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA
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15
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Simonik EA, Cai Y, Kimmelshue KN, Brantley-Sieders DM, Loomans HA, Andl CD, Westlake GM, Youngblood VM, Chen J, Yarbrough WG, Brown BT, Nagarajan L, Brandt SJ. LIM-Only Protein 4 (LMO4) and LIM Domain Binding Protein 1 (LDB1) Promote Growth and Metastasis of Human Head and Neck Cancer (LMO4 and LDB1 in Head and Neck Cancer). PLoS One 2016; 11:e0164804. [PMID: 27780223 PMCID: PMC5079595 DOI: 10.1371/journal.pone.0164804] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 10/01/2016] [Indexed: 12/18/2022] Open
Abstract
Squamous cell carcinoma of the head and neck (HNSCC) accounts for more than 300,000 deaths worldwide per year as a consequence of tumor cell invasion of adjacent structures or metastasis. LIM-only protein 4 (LMO4) and LIM-domain binding protein 1 (LDB1), two directly interacting transcriptional adaptors that have important roles in normal epithelial cell differentiation, have been associated with increased metastasis, decreased differentiation, and shortened survival in carcinoma of the breast. Here, we implicate two LDB1-binding proteins, single-stranded binding protein 2 (SSBP2) and 3 (SSBP3), in controlling LMO4 and LDB1 protein abundance in HNSCC and in regulating specific tumor cell functions in this disease. First, we found that the relative abundance of LMO4, LDB1, and the two SSBPs correlated very significantly in a panel of human HNSCC cell lines. Second, expression of these proteins in tumor primaries and lymph nodes involved by metastasis were concordant in 3 of 3 sets of tissue. Third, using a Matrigel invasion and organotypic reconstruct assay, CRISPR/Cas9-mediated deletion of LDB1 in the VU-SCC-1729 cell line, which is highly invasive of basement membrane and cellular monolayers, reduced tumor cell invasiveness and migration, as well as proliferation on tissue culture plastic. Finally, inactivation of the LDB1 gene in these cells decreased growth and vascularization of xenografted human tumor cells in vivo. These data show that LMO4, LDB1, and SSBP2 and/or SSBP3 regulate metastasis, proliferation, and angiogenesis in HNSCC and provide the first evidence that SSBPs control LMO4 and LDB1 protein abundance in a cancer context.
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Affiliation(s)
- Elizabeth A. Simonik
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Ying Cai
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Katherine N. Kimmelshue
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Dana M. Brantley-Sieders
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Holli A. Loomans
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Claudia D. Andl
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Grant M. Westlake
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Victoria M. Youngblood
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Jin Chen
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Cell & Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States of America
- VA Tennessee Valley Healthcare System, Nashville, TN, United States of America
| | - Wendell G. Yarbrough
- Department of Otolaryngology and Barry Baker Laboratory for Head and Neck Oncology, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Brandee T. Brown
- Department of Otolaryngology and Barry Baker Laboratory for Head and Neck Oncology, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Lalitha Nagarajan
- Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States of America
| | - Stephen J. Brandt
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Department of Cell & Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States of America
- VA Tennessee Valley Healthcare System, Nashville, TN, United States of America
- * E-mail:
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16
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Takahashi K, Sumarriva K, Kim R, Jiang R, Brantley-Sieders DM, Chen J, Mernaugh RL, Takahashi T. Determination of the CD148-Interacting Region in Thrombospondin-1. PLoS One 2016; 11:e0154916. [PMID: 27149518 PMCID: PMC4858292 DOI: 10.1371/journal.pone.0154916] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 04/21/2016] [Indexed: 11/28/2022] Open
Abstract
CD148 is a transmembrane protein tyrosine phosphatase that is expressed in multiple cell types, including vascular endothelial cells and duct epithelial cells. Previous studies have shown a prominent role of CD148 to reduce growth factor signals and suppress cell proliferation and transformation. Further, we have recently shown that thrombospondin-1 (TSP1) serves as a functionally important ligand for CD148. TSP1 has multiple structural elements and interacts with various cell surface receptors that exhibit differing effects. In order to create the CD148-specific TSP1 fragment, here we investigated the CD148-interacting region in TSP1 using a series of TSP1 fragments and biochemical and biological assays. Our results demonstrate that: 1) CD148 binds to the 1st type 1 repeat in TSP1; 2) Trimeric TSP1 fragments that contain the 1st type repeat inhibit cell proliferation in A431D cells that stably express wild-type CD148 (A431D/CD148wt cells), while they show no effects in A431D cells that lack CD148 or express a catalytically inactive form of CD148. The anti-proliferative effect of the TSP1 fragment in A431D/CD148wt cells was largely abolished by CD148 knockdown and antagonized by the 1st, but not the 2nd and 3rd, type 1 repeat fragment. Furthermore, the trimeric TSP1 fragments containing the 1st type repeat increased the catalytic activity of CD148 and reduced phospho-tyrosine contents of EGFR and ERK1/2, defined CD148 substrates. These effects were not observed in the TSP1 fragments that lack the 1st type 1 repeat. Last, we demonstrate that the trimeric TSP1 fragment containing the 1st type 1 repeat inhibits endothelial cell proliferation in culture and angiogenesis in vivo. These effects were largely abolished by CD148 knockdown or deficiency. Collectively, these findings indicate that the 1st type 1 repeat interacts with CD148, reducing growth factor signals and inhibiting epithelial or endothelial cell proliferation and angiogenesis.
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Affiliation(s)
- Keiko Takahashi
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Katherine Sumarriva
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Rachel Kim
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Rosie Jiang
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Dana M. Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Jin Chen
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Raymond L. Mernaugh
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Takamune Takahashi
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
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17
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Youngblood VM, Kim LC, Edwards DN, Hwang Y, Santapuram PR, Stirdivant SM, Lu P, Ye F, Brantley-Sieders DM, Chen J. The Ephrin-A1/EPHA2 Signaling Axis Regulates Glutamine Metabolism in HER2-Positive Breast Cancer. Cancer Res 2016; 76:1825-36. [PMID: 26833123 DOI: 10.1158/0008-5472.can-15-0847] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 12/20/2015] [Indexed: 11/16/2022]
Abstract
Dysregulation of receptor tyrosine kinases (RTK) contributes to cellular transformation and cancer progression by disrupting key metabolic signaling pathways. The EPHA2 RTK is overexpressed in aggressive forms of breast cancer, including the HER2(+) subtype, and correlates with poor prognosis. However, the role of EPHA2 in tumor metabolism remains unexplored. In this study, we used in vivo and in vitro models of HER2-overexpressing breast cancer to investigate the mechanisms by which EPHA2 ligand-independent signaling promotes tumorigenesis in the absence of its prototypic ligand, ephrin-A1. We demonstrate that ephrin-A1 loss leads to upregulated glutamine metabolism and lipid accumulation that enhanced tumor growth. Global metabolic profiling of ephrin-A1-null, HER2-overexpressing mammary tumors revealed a significant increase in glutaminolysis, a critical metabolic pathway that generates intermediates for lipogenesis. Pharmacologic inhibition of glutaminase activity reduced tumor growth in both ephrin-A1-depleted and EPHA2-overexpressing tumor allografts in vivo Mechanistically, we show that the enhanced proliferation and glutaminolysis in the absence of ephrin-A1 were attributed to increased RhoA-dependent glutaminase activity. EPHA2 depletion or pharmacologic inhibition of Rho, glutaminase, or fatty acid synthase abrogated the increased lipid content and proliferative effects of ephrin-A1 knockdown. Together, these findings highlight a novel, unsuspected connection between the EPHA2/ephrin-A1 signaling axis and tumor metabolism, and suggest potential new therapeutic targets in cancer subtypes exhibiting glutamine dependency. Cancer Res; 76(7); 1825-36. ©2016 AACR.
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Affiliation(s)
| | - Laura C Kim
- Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Deanna N Edwards
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, Tennessee
| | - Yoonha Hwang
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, Tennessee. Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
| | | | | | - Pengcheng Lu
- Department of Biostatistics, Vanderbilt University, Nashville, Tennessee
| | - Fei Ye
- Department of Biostatistics, Vanderbilt University, Nashville, Tennessee
| | - Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, Tennessee. Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee.
| | - Jin Chen
- Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee. Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, Tennessee. Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee. Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee. Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee.
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18
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Brantley-Sieders DM, Morrison MM, Hicks DJ, Cook RS. Abstract 4198: mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-4198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Akt phosphorylation is a major driver of cell survival, motility, and proliferation in development and disease, causing increased interest in upstream regulators of Akt like mTOR complex 2 (mTORC2). We used genetic disruption of Rictor to impair mTORC2 activity in mouse mammary epithelia, which decreased Akt phosphorylation, ductal length, secondary branching, cell motility, and cell survival. These effects were recapitulated with a pharmacological dual inhibitor of mTORC1/mTORC2, but not upon genetic disruption of mTORC1 function via Raptor knock-out. Surprisingly, Akt re-activation was insufficient to rescue survival, branching, or motility of mTORC2-impaired mammary epithelial cells (MECs). However, activation of the mTORC2 substrate protein kinase C (PKC)-α fully rescued branching, invasion, and survival of MECs after genetic or pharmacological mTORC2 inhibition. PKCα-mediated signaling through the small GTPase Rac1 was necessary for mTORC2-dependent mammary morphogenesis, revealing a novel role for Rictor/mTORC2 in survival and motility of untransformed MECs through an Akt-independent, PKCα/Rac1-dependent mechanism. Ongoing analyses of mammary specific Rictor-deletion in genetically engineered mouse models of breast cancer support a key role for mTORC2 in tumor progression and metastasis.
Citation Format: Dana M. Brantley-Sieders, Meghan M. Morrison, Donna J. Hicks, Rebecca S. Cook. mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4198. doi:10.1158/1538-7445.AM2015-4198
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19
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Morrison MM, Young CD, Wang S, Sanchez VM, Rebecca CS, Hicks DJ, Brantley-Sieders DM. Abstract B49: mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt. Mol Cancer Ther 2015. [DOI: 10.1158/1538-8514.pi3k14-b49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Akt phosphorylation is a major driver of cell survival, motility, and proliferation in development and disease, causing increased interest in upstream regulators of Akt like mTOR complex 2 (mTORC2). We used genetic disruption of Rictor to impair mTORC2 activity in mouse mammary epithelia, which decreased Akt phosphorylation, ductal length, secondary branching, cell motility, and cell survival. These effects were recapitulated with a pharmacological dual inhibitor of mTORC1/mTORC2, but not upon genetic disruption of mTORC1 function via Raptor knock-out. Surprisingly, Akt re-activation was insufficient to rescue survival, branching, or motility of mTORC2-impaired mammary epithelial cells (MECs). However, activation of the mTORC2 substrate protein kinase C (PKC)-α fully rescued branching, invasion, and survival of MECs after genetic or pharmacological mTORC2 inhibition. PKCα-mediated signaling through the small GTPase Rac1 was necessary for mTORC2-dependent mammary morphogenesis, revealing a novel role for Rictor/mTORC2 in survival and motility of untransformed MECs through an Akt-independent, PKCα/Rac1-dependent mechanism.
Citation Format: Meghan M. Morrison, Christian D. Young, Shan Wang, Violeta M. Sanchez, Cook S. Rebecca, Donna J. Hicks, Dana M. Brantley-Sieders. mTORC2 directs breast morphogenesis through Rictor-dependent PKCα/Rac1 signaling independent of Akt. [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr B49.
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Affiliation(s)
| | | | - Shan Wang
- Vanderbilt University Medical Center, Nashville, TN
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Morrison MM, Young CD, Wang S, Sobolik T, Sanchez VM, Hicks DJ, Cook RS, Brantley-Sieders DM. mTOR Directs Breast Morphogenesis through the PKC-alpha-Rac1 Signaling Axis. PLoS Genet 2015; 11:e1005291. [PMID: 26132202 PMCID: PMC4488502 DOI: 10.1371/journal.pgen.1005291] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 05/18/2015] [Indexed: 12/21/2022] Open
Abstract
Akt phosphorylation is a major driver of cell survival, motility, and proliferation in development and disease, causing increased interest in upstream regulators of Akt like mTOR complex 2 (mTORC2). We used genetic disruption of Rictor to impair mTORC2 activity in mouse mammary epithelia, which decreased Akt phosphorylation, ductal length, secondary branching, cell motility, and cell survival. These effects were recapitulated with a pharmacological dual inhibitor of mTORC1/mTORC2, but not upon genetic disruption of mTORC1 function via Raptor deletion. Surprisingly, Akt re-activation was not sufficient to rescue cell survival or invasion, and modestly increased branching of mTORC2-impaired mammary epithelial cells (MECs) in culture and in vivo. However, another mTORC2 substrate, protein kinase C (PKC)-alpha, fully rescued mTORC2-impaired MEC branching, invasion, and survival, as well as branching morphogenesis in vivo. PKC-alpha-mediated signaling through the small GTPase Rac1 was necessary for mTORC2-dependent mammary epithelial development during puberty, revealing a novel role for Rictor/mTORC2 in MEC survival and motility during branching morphogenesis through a PKC-alpha/Rac1-dependent mechanism. The protein kinase mTOR is frequently activated in breast cancers, where it enhances cancer cell growth, survival, and metastastic spread to distant organs. Thus, mTOR is an attractive, clinically relevant molecular target for drugs designed to treat metastatic breast cancers. However, mTOR exists in two distinct complexes, mTORC1 and mTORC2, and the relative roles of each complex have not been elucidated. Moreover, as pathways that regulate normal tissue growth and development are often highjacked to promote cancer, understanding mTOR function in normal mammary epithelial development will likely provide insight into its role in tumor progression. In this study, we assessed the role of mTORC1 and mTORC2 complexes in normal mammary epithelial cell branching, survival, and invasion. Interestingly, while mTORC1 was not required for branching, survival and invasion of mammary epithelial cells, mTORC2 was necessary for these processes in both mouse and human models. Furthermore, we found that mTORC2 exerts its effects primarily through downstream activation of a PKC-alpha-Rac1 signaling axis rather than the more well-studied Akt signaling pathway. Our studies identify a novel role for the mTORC2 complex in mammary morphogenesis, including cell survival and motility, which are relevant to breast cancer progression.
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Affiliation(s)
- Meghan M. Morrison
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Christian D. Young
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Shan Wang
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Tammy Sobolik
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Violeta M. Sanchez
- Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Donna J. Hicks
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Rebecca S. Cook
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Dana M. Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail:
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Young CD, Zimmerman LJ, Hoshino D, Formisano L, Hanker AB, Gatza ML, Morrison MM, Moore PD, Whitwell CA, Dave B, Stricker T, Bhola NE, Silva GO, Patel P, Brantley-Sieders DM, Levin M, Horiates M, Palma NA, Wang K, Stephens PJ, Perou CM, Weaver AM, O'Shaughnessy JA, Chang JC, Park BH, Liebler DC, Cook RS, Arteaga CL. Activating PIK3CA Mutations Induce an Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-regulated Kinase (ERK) Paracrine Signaling Axis in Basal-like Breast Cancer. Mol Cell Proteomics 2015; 14:1959-76. [PMID: 25953087 DOI: 10.1074/mcp.m115.049783] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Indexed: 12/22/2022] Open
Abstract
Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of phosphoinositide 3-kinase (PI3K) have been shown to transform human mammary epithelial cells (MECs). These mutations are present in all breast cancer subtypes, including basal-like breast cancer (BLBC). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 72 protein expression changes in human basal-like MECs with knock-in E545K or H1047R PIK3CA mutations versus isogenic MECs with wild-type PIK3CA. Several of these were secreted proteins, cell surface receptors or ECM interacting molecules and were required for growth of PIK3CA mutant cells as well as adjacent cells with wild-type PIK3CA. The proteins identified by MS were enriched among human BLBC cell lines and pointed to a PI3K-dependent amphiregulin/EGFR/ERK signaling axis that is activated in BLBC. Proteins induced by PIK3CA mutations correlated with EGFR signaling and reduced relapse-free survival in BLBC. Treatment with EGFR inhibitors reduced growth of PIK3CA mutant BLBC cell lines and murine mammary tumors driven by a PIK3CA mutant transgene, all together suggesting that PIK3CA mutations promote tumor growth in part by inducing protein changes that activate EGFR.
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Affiliation(s)
| | - Lisa J Zimmerman
- §Biochemistry, ‡‡Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | | | | | - Michael L Gatza
- ¶¶Departments of Pathology and Laboratory Medicine and Genetics; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | | | | | - Corbin A Whitwell
- ‡‡Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Thomas Stricker
- ‖Pathology, Microbiology and Immunology; **Breast Cancer Research Program; Vanderbilt Ingram Cancer Center, Nashville, Tennessee
| | | | - Grace O Silva
- ¶¶Departments of Pathology and Laboratory Medicine and Genetics; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | | | | | - Maren Levin
- Baylor Charles A. Sammons Cancer Center, Dallas, Texas
| | | | | | - Kai Wang
- Foundation Medicine, Cambridge, Massachusetts
| | | | - Charles M Perou
- ¶¶Departments of Pathology and Laboratory Medicine and Genetics; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | | | - Joyce A O'Shaughnessy
- Baylor Charles A. Sammons Cancer Center, Dallas, Texas; Texas Oncology, US Oncology, Dallas, Texas
| | | | - Ben Ho Park
- ‖‖The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Daniel C Liebler
- §Biochemistry, ‡‡Jim Ayers Institute for Precancer Detection and Diagnosis, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Rebecca S Cook
- ¶Cancer Biology, **Breast Cancer Research Program; Vanderbilt Ingram Cancer Center, Nashville, Tennessee
| | - Carlos L Arteaga
- From the Departments of ‡Medicine, ¶Cancer Biology, **Breast Cancer Research Program; Vanderbilt Ingram Cancer Center, Nashville, Tennessee;
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Youngblood V, Wang S, Song W, Walter D, Hwang Y, Chen J, Brantley-Sieders DM. Elevated Slit2 Activity Impairs VEGF-Induced Angiogenesis and Tumor Neovascularization in EphA2-Deficient Endothelium. Mol Cancer Res 2014; 13:524-37. [PMID: 25504371 DOI: 10.1158/1541-7786.mcr-14-0142] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Angiogenic remodeling during embryonic development and in adult tissue homeostasis is orchestrated by cooperative signaling between several distinct molecular pathways, which are often exploited by tumors. Indeed, tumors upregulate proangiogenic molecules while simultaneously suppressing angiostatic pathways to recruit blood vessels for growth, survival, and metastatic spread. Understanding how cancers exploit proangiogenic and antiangiogenic signals is a key step in developing new, molecularly targeted antiangiogenic therapies. While EphA2, a receptor tyrosine kinase (RTK), is required for VEGF-induced angiogenesis, the mechanism through which these pathways intersect remains unclear. Slit2 expression is elevated in EphA2-deficient endothelium, and here it is reported that inhibiting Slit activity rescues VEGF-induced angiogenesis in cell culture and in vivo, as well as VEGF-dependent tumor angiogenesis, in EphA2-deficient endothelial cells and animals. Moreover, blocking Slit activity or Slit2 expression in EphA2-deficient endothelial cells restores VEGF-induced activation of Src and Rac, both of which are required for VEGF-mediated angiogenesis. These data suggest that EphA2 suppression of Slit2 expression and Slit angiostatic activity enables VEGF-induced angiogenesis in vitro and in vivo, providing a plausible mechanism for impaired endothelial responses to VEGF in the absence of EphA2 function. IMPLICATIONS Modulation of angiostatic factor Slit2 by EphA2 receptor regulates endothelial responses to VEGF-mediated angiogenesis and tumor neovascularization.
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Affiliation(s)
- Victoria Youngblood
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Shan Wang
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Wenqiang Song
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Debra Walter
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Yoonha Hwang
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jin Chen
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee. Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee. Department of Cellular and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee. Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee. Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
| | - Dana M Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee. Vanderbilt Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee.
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Stanford JC, Young C, Hicks D, Owens P, Williams A, Vaught DB, Morrison MM, Lim J, Williams M, Brantley-Sieders DM, Balko JM, Tonetti D, Earp HS, Cook RS. Efferocytosis produces a prometastatic landscape during postpartum mammary gland involution. J Clin Invest 2014; 124:4737-52. [PMID: 25250573 DOI: 10.1172/jci76375] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/13/2014] [Indexed: 12/27/2022] Open
Abstract
Breast cancers that occur in women 2-5 years postpartum are more frequently diagnosed at metastatic stages and correlate with poorer outcomes compared with breast cancers diagnosed in young, premenopausal women. The molecular mechanisms underlying the malignant severity associated with postpartum breast cancers (ppBCs) are unclear but relate to stromal wound-healing events during postpartum involution, a dynamic process characterized by widespread cell death in milk-producing mammary epithelial cells (MECs). Using both spontaneous and allografted mammary tumors in fully immune-competent mice, we discovered that postpartum involution increases mammary tumor metastasis. Cell death was widespread, not only occurring in MECs but also in tumor epithelium. Dying tumor cells were cleared through receptor tyrosine kinase MerTK-dependent efferocytosis, which robustly induced the transcription of genes encoding wound-healing cytokines, including IL-4, IL-10, IL-13, and TGF-β. Animals lacking MerTK and animals treated with a MerTK inhibitor exhibited impaired efferocytosis in postpartum tumors, a reduction of M2-like macrophages but no change in total macrophage levels, decreased TGF-β expression, and a reduction of postpartum tumor metastasis that was similar to the metastasis frequencies observed in nulliparous mice. Moreover, TGF-β blockade reduced postpartum tumor metastasis. These data suggest that widespread cell death during postpartum involution triggers efferocytosis-induced wound-healing cytokines in the tumor microenvironment that promote metastatic tumor progression.
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Amato KR, Wang S, Hastings AK, Youngblood VM, Santapuram PR, Chen H, Cates JM, Colvin DC, Ye F, Brantley-Sieders DM, Cook RS, Tan L, Gray NS, Chen J. Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC. J Clin Invest 2014; 124:2037-49. [PMID: 24713656 DOI: 10.1172/jci72522] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 02/20/2014] [Indexed: 01/15/2023] Open
Abstract
Genome-wide analyses determined previously that the receptor tyrosine kinase (RTK) EPHA2 is commonly overexpressed in non-small cell lung cancers (NSCLCs). EPHA2 overexpression is associated with poor clinical outcomes; therefore, EPHA2 may represent a promising therapeutic target for patients with NSCLC. In support of this hypothesis, here we have shown that targeted disruption of EphA2 in a murine model of aggressive Kras-mutant NSCLC impairs tumor growth. Knockdown of EPHA2 in human NSCLC cell lines reduced cell growth and viability, confirming the epithelial cell autonomous requirements for EPHA2 in NSCLCs. Targeting EPHA2 in NSCLCs decreased S6K1-mediated phosphorylation of cell death agonist BAD and induced apoptosis. Induction of EPHA2 knockdown within established NSCLC tumors in a subcutaneous murine model reduced tumor volume and induced tumor cell death. Furthermore, an ATP-competitive EPHA2 RTK inhibitor, ALW-II-41-27, reduced the number of viable NSCLC cells in a time-dependent and dose-dependent manner in vitro and induced tumor regression in human NSCLC xenografts in vivo. Collectively, these data demonstrate a role for EPHA2 in the maintenance and progression of NSCLCs and provide evidence that ALW-II-41-27 effectively inhibits EPHA2-mediated tumor growth in preclinical models of NSCLC.
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MESH Headings
- Animals
- Apoptosis
- Carcinoma, Non-Small-Cell Lung/drug therapy
- Carcinoma, Non-Small-Cell Lung/enzymology
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/pathology
- Cell Line, Tumor
- Cell Survival
- Heterografts
- Humans
- Lung Neoplasms/drug therapy
- Lung Neoplasms/enzymology
- Lung Neoplasms/genetics
- Lung Neoplasms/pathology
- Mice
- Mice, Knockout
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Neoplasm Transplantation
- Protein Kinase Inhibitors/pharmacology
- Receptor, EphA2/antagonists & inhibitors
- Receptor, EphA2/genetics
- Receptor, EphA2/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/genetics
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Ribosomal Protein S6 Kinases, 90-kDa/genetics
- Ribosomal Protein S6 Kinases, 90-kDa/metabolism
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Young CD, Zimmerman LJ, Whitwell CA, Hanker AB, Stricker T, Brantley-Sieders DM, Park BH, Liebler DC, Cook RS, Arteaga CL. Abstract B015: Knock-in of PIK3CA mutations in MCF10A mammary epithelial cells modifies their proteomic profile to resemble basal-like breast cancer and stimulate EGFR-dependent cell proliferation. Mol Cancer Res 2013. [DOI: 10.1158/1557-3125.advbc-b015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
PIK3CA, the gene encoding the p110α catalytic subunit of phosphatidylinositol-3 kinase (PI3K), is frequently mutated in breast cancer. Activating mutations in PIK3CA are known to transform mammary epithelial cells (MECs). Genomic knock-in of the two most frequent hot-spot PIK3CA mutations (E545K or H1047R) into MCF10A MECs resulted in growth factor-independent proliferation. Shotgun LC-MS/MS mass spectrometry analysis of wild type, E545K and H1047R MCF10A cell lysates revealed 73 proteins uniquely altered in the both mutant cell lines compared to wild type cells. KEGG pathway analysis demonstrated that PIK3CA mutant cells have elevated levels of proteins involved in focal adhesion, ECM-receptor interactions and actin cytoskeleton regulation. Nearly half the proteins upregulated in the mutant cells are secreted or involved in extracellular matrix (ECM) processing or signaling. The EGFR ligand amphiregulin was five-fold higher in the conditioned media harvested from PIK3CA mutant cells as compared to wild type cells. The conditioned media of PIK3CA mutant cells, but not that of wild-type cells, was sufficient to stimulate proliferation and EGFR phosphorylation in wild type MCF10A cells. Proliferation and EGFR activation were inhibited with an amphiregulin-neutralizing antibody or with EGFR neutralizing antibodies and kinase inhibitors. PIK3CA mutant cells downregulated PTPRF, a receptor tyrosine phosphatase. EGFR signaling and proliferation were stimulated in wild type cells when PTPRF was downregulated with siRNA, suggesting that PIK3CA mutant MCF10A cells activate EGFR-dependent proliferation by suppression of a negative regulatory phosphatase and increased secretion of amphiregulin.
The expression of transglutaminase 2, peroxidasin, fibronectin, integrin α5, laminin β3, laminin γ2, thrombospondin and EphA2, eight proteins upregulated in PIK3CA mutant MCF10A cells, was evaluated in a panel of breast cancer cell lines. All eight proteins were more highly expressed in basal-like compared to luminal-like breast cancer cell lines. The expression of PTPRF, which is decreased in PIK3CA mutant MCF10A cells, was lower in basal-like cell lines. Interrogation of microarray data demonstrated that the RNA signal of proteins upregulated in mutant PIK3CA MCF10A cells correlated with decreased relapse-free survival in basal-like, but not in luminal-like breast cancer. siRNA-mediated silencing of peroxidasin, laminin γ2, EphA2, integrin β1 or amphiregulin reduced the proliferation of PIK3CA mutant MCF10A cells, suggesting that these proteins are necessary for maintenance of the transformed phenotype. siRNA-mediated silencing of peroxidasin and EphA2 proteins also reduces the proliferation of basal-like breast cancer cells. Our proteomic analysis of PIK3CA mutant MCF10A cells revealed mechanisms of autocrine and paracrine induced proliferation and alterations mostly limited to basal-like breast cancer cells. These may serve as therapeutic targets in this subtype of breast cancer.
Citation Format: Christian D. Young, Lisa J. Zimmerman, Corbin A. Whitwell, Ariella B. Hanker, Thomas Stricker, Dana M. Brantley-Sieders, Ben Ho Park, Daniel C. Liebler, Rebecca S. Cook, Carlos L. Arteaga. Knock-in of PIK3CA mutations in MCF10A mammary epithelial cells modifies their proteomic profile to resemble basal-like breast cancer and stimulate EGFR-dependent cell proliferation. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B015.
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Morrison MM, Hicks D, Cook RS, Brantley-Sieders DM. Abstract A118: The mTORC2 component Rictor directs branching morphogenesis and survival in the mammary epithelium. Mol Cancer Res 2013. [DOI: 10.1158/1557-3125.advbc-a118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The intracellular serine/threonine kinase mTOR functions in two distinct complexes that integrate many cellular cues to regulate diverse processes in development and disease. Raptor-dependent mTOR Complex-1 (mTORC1) mediates cell growth and metabolism, whereas the less well-studied Rictor-dependent mTOR Complex-2 (mTORC2) promotes cell survival and cytoskeletal organization. Previous studies link mTORC1 to malignant transformation of mammary epithelial cells (MECs). The role of mTOR and the relative contributions of mTORC1 versus mTORC2 in postnatal mammary morphogenesis, however, remain unclear. We report that mTORC2 ablation via Rictor loss impaired branching morphogenesis, MEC survival, MEC migration, and mTORC2-mediated signaling through Akt and Rac1-GTPase in vivo and ex vivo. Constitutively active Rac1 (CA-Rac1) rescued branching, invasion, and survival of mTORC2-impaired MECs, but CA-Akt did not. These effects were recapitulated by rapamycin treatment. Surprisingly, genetic mTORC1 disruption via Raptor gene targeting did not affect ascinar mammary morphogenesis in organoids or in vivo, but did cause decreased signaling through the mTORC1 effector ribosomal protein S6 and transiently slowed cellular proliferation. These data demonstrate the distinct, non-overlapping properties of mTORC1 and mTORC2 during post-natal mammary development, roles which may be preserved in breast cancers.
Citation Format: Meghan M. Morrison, Donna Hicks, Rebecca S. Cook, Dana M. Brantley-Sieders. The mTORC2 component Rictor directs branching morphogenesis and survival in the mammary epithelium. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A118.
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Affiliation(s)
| | - Donna Hicks
- Vanderbilt University Medical Center, Nashville, TN
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Zhuang G, Song W, Amato K, Hwang Y, Lee K, Boothby M, Ye F, Guo Y, Shyr Y, Lin L, Carbone DP, Brantley-Sieders DM, Chen J. Effects of cancer-associated EPHA3 mutations on lung cancer. J Natl Cancer Inst 2012; 104:1182-97. [PMID: 22829656 DOI: 10.1093/jnci/djs297] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Cancer genome sequencing efforts recently identified EPHA3, which encodes the EPHA3 receptor tyrosine kinase, as one of the most frequently mutated genes in lung cancer. Although receptor tyrosine kinase mutations often drive oncogenic conversion and tumorigenesis, the oncogenic potential of the EPHA3 mutations in lung cancer remains unknown. METHODS We used immunoprecipitation, western blotting, and kinase assays to determine the activity and signaling of mutant EPHA3 receptors. A mutation-associated gene signature was generated from one large dataset, mapped to another training dataset with survival information, and tested in a third independent dataset. EPHA3 expression levels were determined by quantitative reverse transcription-polymerase chain reaction in paired normal-tumor clinical specimens and by immunohistochemistry in human lung cancer tissue microarrays. We assessed tumor growth in vivo using A549 and H1299 human lung carcinoma cell xenografts in mice (n = 7-8 mice per group). Tumor cell proliferation was measured by bromodeoxyuridine incorporation and apoptosis by multiple assays. All P values are from two-sided tests. RESULTS At least two cancer-associated EPHA3 somatic mutations functioned as dominant inhibitors of the normal (wild type) EPHA3 protein. An EPHA3 mutation-associated gene signature that was associated with poor patient survival was identified. Moreover, EPHA3 gene copy numbers and/or expression levels were decreased in tumors from large cohorts of patients with lung cancer (eg, the gene was deleted in 157 of 371 [42%] primary lung adenocarcinomas). Reexpression of wild-type EPHA3 in human lung cancer lines increased apoptosis by suppression of AKT activation in vitro and inhibited the growth of tumor xenografts (eg, for H1299 cells, mean tumor volume with wild-type EPHA3 = 437.4 mm(3) vs control = 774.7 mm(3), P < .001). Tumor-suppressive effects of wild-type EPHA3 could be overridden in trans by dominant negative EPHA3 somatic mutations discovered in patients with lung cancer. CONCLUSION Cancer-associated EPHA3 mutations attenuate the tumor-suppressive effects of normal EPHA3 in lung cancer.
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Affiliation(s)
- Guanglei Zhuang
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Brantley-Sieders DM. Clinical relevance of Ephs and ephrins in cancer: lessons from breast, colorectal, and lung cancer profiling. Semin Cell Dev Biol 2011; 23:102-8. [PMID: 22040912 DOI: 10.1016/j.semcdb.2011.10.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 10/17/2011] [Indexed: 01/04/2023]
Abstract
Pre-clinical studies provide compelling evidence that members of the Eph family of receptor tyrosine kinases and their ephrin ligands promote tumor growth, invasion and metastasis, and neovascularization. Tumor suppressive roles have also been reported for the receptors, and ligand-dependent versus ligand-independent signaling has emerged as one key mechanism underlying tumor suppressive function as opposed to oncogenic effects. Determining how these observations relate to clinical outcome is a crucial step for translating the biological and mechanistic data into new molecularly targeted therapies. Expression profiling in human patient samples bridges this gap and provides valuable clinical relevance to laboratory observations. In addition to analyses performed using privately assembled patient tumor samples, publically available microarray datasets and tissue microarrays linked to clinical data have emerged as tractable tools for addressing the clinical relevance of specific molecules and families of related molecules. This review summarizes the clinical relevance of specific Eph and ephrin molecules in human breast, colorectal, and lung cancers.
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Affiliation(s)
- Dana M Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, A-4323 MCN, 1161 21st Avenue South, Nashville, TN 37232-2363, USA.
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Brantley-Sieders DM, Dunaway CM, Rao M, Short S, Hwang Y, Gao Y, Li D, Jiang A, Shyr Y, Wu JY, Chen J. Angiocrine factors modulate tumor proliferation and motility through EphA2 repression of Slit2 tumor suppressor function in endothelium. Cancer Res 2010; 71:976-87. [PMID: 21148069 DOI: 10.1158/0008-5472.can-10-3396] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It is well known that tumor-derived proangiogenic factors induce neovascularization to facilitate tumor growth and malignant progression. However, the concept of "angiocrine" signaling, in which signals produced by endothelial cells elicit tumor cell responses distinct from vessel function, has been proposed, yet remains underinvestigated. Here, we report that angiocrine factors secreted from endothelium regulate tumor growth and motility. We found that Slit2, which is negatively regulated by endothelial EphA2 receptor, is one such tumor suppressive angiocrine factor. Slit2 activity is elevated in EphA2-deficient endothelium. Blocking Slit activity restored angiocrine-induced tumor growth/motility, whereas elevated Slit2 impaired growth/motility. To translate our findings to human cancer, we analyzed EphA2 and Slit2 expression in human cancer. EphA2 expression inversely correlated with Slit2 in the vasculature of invasive human ductal carcinoma samples. Moreover, analysis of large breast tumor data sets revealed that Slit2 correlated positively with overall and recurrence-free survival, providing clinical validation for the tumor suppressor function for Slit2 in human breast cancer. Together, these data support a novel, clinically relevant mechanism through which EphA2 represses Slit2 expression in endothelium to facilitate angiocrine-mediated tumor growth and motility by blocking a tumor suppressive signal.
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Affiliation(s)
- Dana M Brantley-Sieders
- Department of Medicine and Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2363, USA
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Zhuang G, Brantley-Sieders DM, Vaught D, Yu J, Xie L, Wells S, Jackson D, Muraoka-Cook R, Arteaga C, Chen J. Elevation of receptor tyrosine kinase EphA2 mediates resistance to trastuzumab therapy. Cancer Res 2009; 70:299-308. [PMID: 20028874 DOI: 10.1158/0008-5472.can-09-1845] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
One arising challenge in the treatment of breast cancer is the development of therapeutic resistance to trastuzumab, an antibody targeting the human epidermal growth factor receptor-2 (HER2), which is frequently amplified in breast cancers. In this study, we provide evidence that elevated level of the receptor tyrosine kinase Eph receptor A2 (EphA2) is an important contributor to trastuzumab resistance. In a screen of a large cohort of human breast cancers, we found that EphA2 overexpression correlated with a decrease in disease-free and overall survival of HER2-overexpressing patients. Trastuzumab-resistant cell lines overexpressed EphA2, whereas inhibiting EphA2 restored sensitivity to trastuzumab treatment in vivo. Notably, trastuzumab treatment could promote EphA2 phosphorylation by activating Src kinase, leading in turn to an amplification of phosphoinositide 3-kinase/Akt and mitogen-activated protein kinase signaling in resistant cells. Our findings offer mechanistic insights into the basis for trastuzumab resistance and rationalize strategies to target EphA2 as a tactic to reverse trastuzumab resistance.
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Affiliation(s)
- Guanglei Zhuang
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tenessee 37232, USA
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31
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Brantley-Sieders DM, Zhuang G, Vaught D, Freeman T, Hwang Y, Hicks D, Chen J. Host deficiency in Vav2/3 guanine nucleotide exchange factors impairs tumor growth, survival, and angiogenesis in vivo. Mol Cancer Res 2009; 7:615-23. [PMID: 19435813 PMCID: PMC2739740 DOI: 10.1158/1541-7786.mcr-08-0401] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vav guanine nucleotide exchange factors modulate changes in cytoskeletal organization through activation of Rho, Rac, and Cdc42 small GTPases. Although Vav1 expression is restricted to the immune system, Vav2 and Vav3 are expressed in several tissues, including highly vascularized organs. Here, we provide the first evidence that Vav2 and Vav3 function within the tumor microenvironment to promote tumor growth, survival, and neovascularization. Host Vav2/3 deficiency reduced microvascular density, as well as tumor growth and/or survival, in transplanted B16 melanoma and Lewis lung carcinoma models in vivo. These defects were due in part to Vav2/3 deficiency in endothelial cells. Vav2/3-deficient endothelial cells displayed reduced migration in response to tumor cells in coculture migration assays, and failed to incorporate into tumor vessels and enhance tumor volume in tumor-endothelial cotransplantation experiments. These data suggest that Vav2/3 guanine nucleotide exchange factors play a critical role in host-mediated tumor progression and angiogenesis, particularly in tumor endothelium.
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MESH Headings
- Animals
- Carcinoma, Lewis Lung/blood supply
- Carcinoma, Lewis Lung/pathology
- Carcinoma, Lewis Lung/physiopathology
- Cell Line, Tumor
- Cell Movement
- Cell Proliferation
- Cell Survival
- Coculture Techniques
- Endothelial Cells/cytology
- Endothelial Cells/physiology
- Melanoma, Experimental/blood supply
- Melanoma, Experimental/pathology
- Melanoma, Experimental/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Nude
- Neoplasms, Experimental/blood supply
- Neoplasms, Experimental/pathology
- Neoplasms, Experimental/physiopathology
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Proto-Oncogene Proteins c-vav/deficiency
- Proto-Oncogene Proteins c-vav/genetics
- Proto-Oncogene Proteins c-vav/physiology
- Transplantation, Homologous
- Tumor Burden
- von Willebrand Factor/metabolism
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Affiliation(s)
- Dana M. Brantley-Sieders
- Department of Medicine, Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Guanglei Zhuang
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - David Vaught
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Tanner Freeman
- Medical Scientist Training Program, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Yoonha Hwang
- Department of Medicine, Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Donna Hicks
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
| | - Jin Chen
- Department of Medicine, Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232 USA
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32
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Abstract
Eph receptor tyrosine kinases, including EphA2, are expressed in the mammary gland. However, their role in mammary gland development remains poorly understood. Using EphA2-deficient animals, we demonstrate for the first time that EphA2 receptor function is required for mammary epithelial growth and branching morphogenesis. Loss of EphA2 decreased penetration of mammary epithelium into fat pad, reduced epithelial proliferation, and inhibited epithelial branching. These defects appear to be intrinsic to loss of EphA2 in epithelium, as transplantation of EphA2-deficient mammary tissue into wild-type recipient stroma recapitulated these defects. In addition, HGF-induced mammary epithelial branching morphogenesis was significantly reduced in EphA2-deficient cells relative to wild-type cells, which correlated with elevated basal RhoA activity. Moreover, inhibition of ROCK kinase activity in EphA2-deficient mammary epithelium rescued branching defects in primary three-dimensional cultures. These results suggest that EphA2 receptor acts as a positive regulator in mammary gland development, functioning downstream of HGF to regulate branching through inhibition of RhoA. Together, these data demonstrate a positive role for EphA2 during normal mammary epithelial proliferation and branching morphogenesis.
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Affiliation(s)
- David Vaught
- Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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33
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Li B, Vincent A, Cates J, Brantley-Sieders DM, Polk DB, Young PP. Low levels of tumor necrosis factor alpha increase tumor growth by inducing an endothelial phenotype of monocytes recruited to the tumor site. Cancer Res 2009; 69:338-48. [PMID: 19118019 DOI: 10.1158/0008-5472.can-08-1565] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microenvironmental cues instruct infiltrating tumor-associated myeloid cells to drive malignant progression. A subpopulation of tumor-associated myeloid cells coexpressing endothelial and myeloid markers, although rare in peripheral blood, are primarily associated with tumors where they enhance tumor growth and angiogenesis. These biphenotypic vascular leukocytes result from the endothelial differentiation of myeloid progenitors, a process regulated by tumor necrosis factor (TNF)alpha in vitro. An in vivo increase in tumor-derived TNFalpha expression promoted tumor growth and vascularity of mouse melanoma, lung cancer, and mammary tumors. Notably, tumor growth was accompanied by a significant increase in myeloid/endothelial biphenotypic populations. TNFalpha-associated tumor growth, vascularity, and generation of tumor vascular leukocytes in mouse melanoma tumors were dependent on intact host TNFalpha receptors. Importantly, TNFalpha-expressing tumors did not exhibit increased inflammation over control tumors, suggesting a unique action related to myeloid to endothelial differentiation. Our studies suggest that TNFalpha constitutes a tumor microenvironment signal that biases recruited monocytes toward a proangiogenic/provasculogenic myeloid/endothelial phenotype.
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Affiliation(s)
- Bin Li
- The Department of Veterans Affairs Medical Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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34
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Abstract
Eph receptor tyrosine kinase signaling regulates cancer initiation and metastatic progression through multiple mechanisms. Studies of tumor-cell-autonomous effects of Eph receptors demonstrate their dual roles in tumor suppression and tumor promotion. In addition, Eph molecules function in the tumor microenvironment, such as in vascular endothelial cells, influencing the ability of these molecules to promote carcinoma progression and metastasis. The complex nature of Eph receptor signaling and crosstalk with other receptor tyrosine kinases presents a unique challenge and an opportunity to develop therapeutic intervention strategies for targeting breast cancer.
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Affiliation(s)
- David Vaught
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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35
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Fang WB, Brantley-Sieders DM, Hwang Y, Ham AJL, Chen J. Identification and functional analysis of phosphorylated tyrosine residues within EphA2 receptor tyrosine kinase. J Biol Chem 2008; 283:16017-26. [PMID: 18387945 PMCID: PMC2414276 DOI: 10.1074/jbc.m709934200] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/14/2008] [Indexed: 11/06/2022] Open
Abstract
EphA2 is a member of the Eph family of receptor tyrosine kinases. EphA2 mediates cell-cell communication and plays critical roles in a number of physiological and pathologic responses. We have previously shown that EphA2 is a key regulator of tumor angiogenesis and that tyrosine phosphorylation regulates EphA2 signaling. To understand the role of EphA2 phosphorylation, we have mapped phosphorylated tyrosines within the intracellular region of EphA2 by a combination of mass spectrometry analysis and phosphopeptide mapping using two-dimensional chromatography in conjunction with site-directed mutagenesis. The function of these phosphorylated tyrosine residues was assessed by mutational analysis using EphA2-null endothelial cells reconstituted with EphA2 tyrosine-to-phenylalanine or tyrosine-to-glutamic acid substitution mutants. Phosphorylated Tyr(587) and Tyr(593) bind to Vav2 and Vav3 guanine nucleotide exchange factors, whereas Tyr(P)(734) binds to the p85 regulatory subunit of phosphatidylinositol 3-kinase. Mutations that uncouple EphA2 with Vav guanine nucleotide exchange factors or p85 are defective in Rac1 activation and cell migration. Finally, EphA2 mutations in the juxtamembrane region (Y587F, Y593F, Y587E/Y593E), kinase domain (Y734F), or SAM domain (Y929F) inhibited ephrin-A1-induced vascular assembly. In addition, EphA2-null endothelial cells reconstituted with these mutants were unable to incorporate into tumor vasculature, suggesting a critical role of these phosphorylation tyrosine residues in transducing EphA2 signaling in vascular endothelial cells during tumor angiogenesis.
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Affiliation(s)
- Wei Bin Fang
- Department of Cancer Biology,
Department of Medicine, Division of
Rheumatology and Immunology,
Proteomics Laboratory, Mass
Spectrometry Research Center,
Department of Cell and Developmental
Biology, and Vanderbilt-Ingram Cancer
Center, Vanderbilt University School of Medicine, Nashville, Tennessee
37232
| | - Dana M. Brantley-Sieders
- Department of Cancer Biology,
Department of Medicine, Division of
Rheumatology and Immunology,
Proteomics Laboratory, Mass
Spectrometry Research Center,
Department of Cell and Developmental
Biology, and Vanderbilt-Ingram Cancer
Center, Vanderbilt University School of Medicine, Nashville, Tennessee
37232
| | - Yoonha Hwang
- Department of Cancer Biology,
Department of Medicine, Division of
Rheumatology and Immunology,
Proteomics Laboratory, Mass
Spectrometry Research Center,
Department of Cell and Developmental
Biology, and Vanderbilt-Ingram Cancer
Center, Vanderbilt University School of Medicine, Nashville, Tennessee
37232
| | - Amy-Joan L. Ham
- Department of Cancer Biology,
Department of Medicine, Division of
Rheumatology and Immunology,
Proteomics Laboratory, Mass
Spectrometry Research Center,
Department of Cell and Developmental
Biology, and Vanderbilt-Ingram Cancer
Center, Vanderbilt University School of Medicine, Nashville, Tennessee
37232
| | - Jin Chen
- Department of Cancer Biology,
Department of Medicine, Division of
Rheumatology and Immunology,
Proteomics Laboratory, Mass
Spectrometry Research Center,
Department of Cell and Developmental
Biology, and Vanderbilt-Ingram Cancer
Center, Vanderbilt University School of Medicine, Nashville, Tennessee
37232
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36
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Brantley-Sieders DM, Zhuang G, Hicks D, Fang WB, Hwang Y, Cates JMM, Coffman K, Jackson D, Bruckheimer E, Muraoka-Cook RS, Chen J. The receptor tyrosine kinase EphA2 promotes mammary adenocarcinoma tumorigenesis and metastatic progression in mice by amplifying ErbB2 signaling. J Clin Invest 2008; 118:64-78. [PMID: 18079969 DOI: 10.1172/jci33154] [Citation(s) in RCA: 216] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 10/17/2007] [Indexed: 12/21/2022] Open
Abstract
Overexpression of the receptor tyrosine kinase EPH receptor A2 (EphA2) is commonly observed in aggressive breast cancer and correlates with a poor prognosis. However, while EphA2 has been reported to enhance tumorigenesis, proliferation, and MAPK activation in several model systems, other studies suggest that EphA2 activation diminishes these processes and inhibits the activity of MAPK upon ligand stimulation. In this study, we eliminated EphA2 expression in 2 transgenic mouse models of mammary carcinoma. EphA2 deficiency impaired tumor initiation and metastatic progression in mice overexpressing ErbB2 (also known as Neu) in the mammary epithelium (MMTV-Neu mice), but not in mice overexpressing the polyomavirus middle T antigen in mammary epithelium (MMTV-PyV-mT mice). Histologic and ex vivo analyses of MMTV-Neu mouse mammary epithelium indicated that EphA2 enhanced tumor proliferation and motility. Biochemical analyses revealed that EphA2 formed a complex with ErbB2 in human and murine breast carcinoma cells, resulting in enhanced activation of Ras-MAPK signaling and RhoA GTPase. Additionally, MMTV-Neu, but not MMTV-PyV-mT, tumors were sensitive to therapeutic inhibition of EphA2. These data suggest that EphA2 cooperates with ErbB2 to promote tumor progression in mice and may provide a novel therapeutic target for ErbB2-dependent tumors in humans. Moreover, EphA2 function in tumor progression appeared to depend on oncogene context, an important consideration for the application of therapies targeting EphA2.
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Affiliation(s)
- Dana M Brantley-Sieders
- Department of Medicine, Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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37
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Brantley-Sieders DM, Fang WB, Hwang Y, Hicks D, Chen J. Ephrin-A1 facilitates mammary tumor metastasis through an angiogenesis-dependent mechanism mediated by EphA receptor and vascular endothelial growth factor in mice. Cancer Res 2006; 66:10315-24. [PMID: 17079451 DOI: 10.1158/0008-5472.can-06-1560] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ephrin-A1, the prototypic ligand for EphA receptor tyrosine kinases, is overexpressed in vascularized tumors relative to normal tissue. Moreover, ephrin-A1-Fc fusion proteins induce endothelial cell sprouting, migration, and assembly in vitro, and s.c. vascular remodeling in vivo. Based on these data, we hypothesized that native, membrane-bound ephrin-A1 regulates tumor angiogenesis and progression. We tested this hypothesis using a transplantable mouse mammary tumor model. Small interfering RNA-mediated ephrin-A1 knockdown in metastatic mammary tumor cells significantly diminishes lung metastasis without affecting tumor volume, invasion, intravasation, or lung colonization upon i.v. injection in vivo. Ephrin-A1 knockdown reduced tumor-induced endothelial cell migration in vitro and microvascular density in vivo. Conversely, overexpression of ephrin-A1 in nonmetastatic mammary tumor cells elevated microvascular density and vascular recruitment. Overexpression of ephrin-A1 elevated wild-type but not EphA2-deficient endothelial cell migration toward tumor cells, suggesting that activation of EphA2 on endothelial cells is one mechanism by which ephrin-A1 regulates angiogenesis. Furthermore, ephrin-A1 knockdown diminished, whereas overexpression of ephrin-A1 elevated, vascular endothelial growth factor (VEGF) levels in tumor cell-conditioned medium, suggesting that ephrin-A1-mediated modulation of the VEGF pathway is another mechanism by which membrane-tethered ephrin-A1 regulates angiogenic responses from initially distant host endothelium. These data suggest that ephrin-A1 is a proangiogenic signal, regulating VEGF expression and facilitating angiogenesis-dependent metastatic spread.
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Affiliation(s)
- Dana M Brantley-Sieders
- Division of Rheumatology and Immunology, Department of Medicin, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
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38
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Tang T, Shi Y, Opalenik SR, Brantley-Sieders DM, Chen J, Davidson JM, Brandt SJ. Expression of the TAL1/SCL transcription factor in physiological and pathological vascular processes. J Pathol 2006; 210:121-9. [PMID: 16841371 DOI: 10.1002/path.2028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The TAL1/SCL transcription factor is essential for haematopoietic commitment and vascular remodelling during embryonic development. To help clarify its role in postnatal vascular processes, we characterized the expression of mouse Tal1 protein by immunocytochemistry in several experimental models of blood vessel formation. In adult mice, Tal1 protein was expressed in rare microvascular endothelial cells and in extravascular cells provisionally identified as endothelial progenitors from their morphology, proximity to vessels and expression of vascular endothelial growth factor receptor-2. The number of Tal1-expressing endothelial cells increased significantly but transiently in all the models-hormone-induced ovulation, wound healing and tumour development. Finally, Tal1 protein was detected in the nuclei of newly formed lymphatic endothelial cells in tumour-bearing animals. These results show that TAL1 is expressed by vascular endothelial cells and endothelial progenitors at sites of physiological and pathological neovascularization and suggest a role for this transcription factor in adult vasculogenesis. This work also provides the first evidence for TAL1 expression in lymphangiogenesis.
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Affiliation(s)
- T Tang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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39
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Abstract
Receptor tyrosine kinases of the Eph family are upregulated in several different types of cancer. One family member in particular, the EphA2 receptor, has been linked to breast, prostate, lung and colon cancer, as well as melanoma. However, mechanisms by which EphA2 contributes to tumor progression are far from clear. In certain tumor cell lines, EphA2 receptor is underphosphorylated, raising the question of whether ligand-induced receptor phosphorylation and its kinase activity play a role in oncogenesis. To test directly the role of EphA2 receptor phosphorylation/kinase activity in tumor progression, we generated EphA2 receptor variants that were either lacking the cytoplasmic domain or carrying a point mutation that inhibits its kinase activity. Expression of these EphA2 mutants in breast cancer cells resulted in decreased tumor volume and increased tumor apoptosis in primary tumors. In addition, the numbers of lung metastases were significantly reduced in both experimental and spontaneous metastasis models. Reduced tumor volume and metastasis are not due to defects in tumor angiogenesis, as there is no significant difference in tumor vessel density between wild-type tumors and tumors expressing EphA2-signaling-defective mutants. In contrast, tumor cells expressing the EphA2 mutants are defective in RhoA GTPase activation and cell migration. Taken together, these results suggest that receptor phosphorylation and kinase activity of the EphA2 receptor, at least in part, contribute to tumor malignancy.
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Affiliation(s)
- Wei Bin Fang
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
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40
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Brantley-Sieders DM, Fang WB, Hicks DJ, Zhuang G, Shyr Y, Chen J. Impaired tumor microenvironment in EphA2-deficient mice inhibits tumor angiogenesis and metastatic progression. FASEB J 2005; 19:1884-6. [PMID: 16166198 DOI: 10.1096/fj.05-4038fje] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
EphA2 belongs to a unique family of receptor tyrosine kinases that play critical roles in development and disease. Since EphA2 is required for ephrin-A1 ligand-induced vascular remodeling and is overexpressed in a variety of vascularized human adenocarcinomas, we assessed tumor angiogenesis and metastatic progression in EphA2-deficient host animals. 4T1 metastatic mammary adenocarcinoma cells transplanted subcutaneously and orthotopically into EphA2-deficient female mice displayed decreased tumor volume, tumor cell survival, microvascular density, and lung metastasis relative to tumor-bearing littermate controls. To determine if the phenotype in EphA2-deficient mice was endothelial cell intrinsic, we also analyzed endothelial cells isolated from EphA2-deficient animals for their ability to incorporate into tumor vessels in vivo, as well as to migrate in response to tumor-derived signals in vitro. EphA2-deficient endothelial cells displayed impaired survival and failed to incorporate into tumor microvessels in vivo, and displayed impaired tumor-mediated migration in vitro relative to controls. These data suggest that host EphA2 receptor tyrosine kinase function is required in the tumor microenvironment for tumor angiogenesis and metastatic progression.
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MESH Headings
- Adenocarcinoma/metabolism
- Animals
- Breast Neoplasms/pathology
- Cell Line, Tumor
- Cell Movement
- Cell Survival
- Cell Transplantation
- Collagen/chemistry
- Disease Progression
- Drug Combinations
- Endothelium, Vascular/pathology
- Ephrin-A1/metabolism
- Female
- In Situ Nick-End Labeling
- Lac Operon
- Laminin/chemistry
- Ligands
- Lung/pathology
- Mammary Neoplasms, Animal/blood supply
- Mammary Neoplasms, Animal/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Mice, Transgenic
- Microcirculation
- Microscopy, Fluorescence
- Models, Biological
- Models, Statistical
- Mutation
- Neoplasm Metastasis
- Neoplasm Transplantation
- Neovascularization, Pathologic
- Oxygen/metabolism
- Phenotype
- Platelet Endothelial Cell Adhesion Molecule-1/biosynthesis
- Proteoglycans/chemistry
- Receptor, EphA2/genetics
- Receptor, EphA2/physiology
- Receptors, Eph Family/metabolism
- rac1 GTP-Binding Protein/metabolism
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Affiliation(s)
- Dana M Brantley-Sieders
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2363, USA
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41
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Abstract
Angiogenesis, the process by which new blood vessels sprout and branch from existing vasculature, is crucial for vascular remodeling during embryogenesis and in normal tissue homeostasis, such as in the female reproductive tract. Angiogenesis can also contribute to the pathogenesis of diseases such as cancer and retinopathy. The Eph family of receptor tyrosine kinases and their ligands, called ephrins, has emerged as critical regulators of vascular remodeling in the embryo. More recently, these molecules have been associated with post-natal angiogenic remodeling and tumor neovascularization. This review provides an overview of recent advances in our understanding of Eph/ephrins in angiogenesis, with an emphasis on development and disease, and the potential for targeting these molecules in anti-angiogenic therapy.
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Affiliation(s)
- Dana M Brantley-Sieders
- Department of Medicine, Division of Rhematology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2363, USA
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42
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Brantley-Sieders DM, Caughron J, Hicks D, Pozzi A, Ruiz JC, Chen J. EphA2 receptor tyrosine kinase regulates endothelial cell migration and vascular assembly through phosphoinositide 3-kinase-mediated Rac1 GTPase activation. J Cell Sci 2004; 117:2037-49. [PMID: 15054110 DOI: 10.1242/jcs.01061] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Angiogenesis is critical for vascular remodeling during development and contributes to the pathogenesis of diseases such as cancer. Targeted disruption of several EphB class receptor tyrosine kinases results in vascular remodeling defects during embryogenesis. The role of EphA class receptors in vascular remodeling, however, is not well-characterized. We recently demonstrated that global inhibition of EphA receptors disrupts endothelial migration induced by ephrin, VEGF or tumor-derived signals, though the specific target remained undefined. Here, we report that EphA2 regulates endothelial cell assembly and migration through phosphoinositide (PI) 3-kinase-mediated activation of Rac1 GTPase in two model systems: primary bovine and murine pulmonary microvascular endothelial cells. EphA2-deficient endothelial cells fail to undergo vascular assembly and migration in response to ephrin-A1 in vitro. Ephrin-A1 stimulation induces PI3-kinase-dependent activation of Rac1 in wild-type endothelial cells, whereas EphA2-deficient cells fail to activate Rac1 upon stimulation. Expression of dominant negative PI3-kinase or Rac1 inhibits ephrin-A1-induced endothelial cell migration. Consistent with in vitro data, EphA2-deficient mice show a diminished angiogenic response to ephrin-A1 in vivo. Moreover, EphA2-deficient endothelial cells fail to assemble in vivo when transplanted into recipient mice. These data suggest that EphA2 is an essential regulator of post-natal angiogenesis.
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Affiliation(s)
- Dana M Brantley-Sieders
- Division of Rhematology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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