1
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Majumder A. HER3: Toward the Prognostic Significance, Therapeutic Potential, Current Challenges, and Future Therapeutics in Different Types of Cancer. Cells 2023; 12:2517. [PMID: 37947595 PMCID: PMC10648638 DOI: 10.3390/cells12212517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/14/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023] Open
Abstract
Human epidermal growth factor receptor 3 (HER3) is the only family member of the EGRF/HER family of receptor tyrosine kinases that lacks an active kinase domain (KD), which makes it an obligate binding partner with other receptors for its oncogenic role. When HER3 is activated in a ligand-dependent (NRG1/HRG) or independent manner, it can bind to other receptors (the most potent binding partner is HER2) to regulate many biological functions (growth, survival, nutrient sensing, metabolic regulation, etc.) through the PI3K-AKT-mTOR pathway. HER3 has been found to promote tumorigenesis, tumor growth, and drug resistance in different cancer types, especially breast and non-small cell lung cancer. Given its ubiquitous expression across different solid tumors and role in oncogenesis and drug resistance, there has been a long effort to target HER3. As HER3 cannot be targeted through its KD with small-molecule kinase inhibitors via the conventional method, pharmaceutical companies have used various other approaches, including blocking either the ligand-binding domain or extracellular domain for dimerization with other receptors. The development of treatment options with anti-HER3 monoclonal antibodies, bispecific antibodies, and different combination therapies showed limited clinical efficiency for various reasons. Recent reports showed that the extracellular domain of HER3 is not required for its binding with other receptors, which raises doubt about the efforts and applicability of the development of the HER3-antibodies for treatment. Whereas HER3-directed antibody-drug conjugates showed potentiality for treatment, these drugs are still under clinical trial. The currently understood model for dimerization-induced signaling remains incomplete due to the absence of the crystal structure of HER3 signaling complexes, and many lines of evidence suggest that HER family signaling involves more than the interaction of two members. This review article will significantly expand our knowledge of HER3 signaling and shed light on developing a new generation of drugs that have fewer side effects than the current treatment regimen for these patients.
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Affiliation(s)
- Avisek Majumder
- Department of Medicine, University of California, San Francisco, CA 94158, USA
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2
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The Landscape of PDK1 in Breast Cancer. Cancers (Basel) 2022; 14:cancers14030811. [PMID: 35159078 PMCID: PMC8834120 DOI: 10.3390/cancers14030811] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/31/2021] [Indexed: 02/04/2023] Open
Abstract
Given that 3-phosphoinositide-dependent kinase 1 (PDK1) plays a crucial role in the malignant biological behaviors of a wide range of cancers, we review the influence of PDK1 in breast cancer (BC). First, we describe the power of PDK1 in cellular behaviors and characterize the interaction networks of PDK1. Then, we establish the roles of PDK1 in carcinogenesis, growth and survival, metastasis, and chemoresistance in BC cells. More importantly, we sort the current preclinical or clinical trials of PDK1-targeted therapy in BC and find that, even though no selective PDK1 inhibitor is currently available for BC therapy, the combination trials of PDK1-targeted therapy and other agents have provided some benefit. Thus, there is increasing anticipation that PDK1-targeted therapy will have its space in future therapeutic approaches related to BC, and we hope the novel approaches of targeted therapy will be conducive to ameliorating the dismal prognosis of BC patients.
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3
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Ghomlaghi M, Yang G, Shin SY, James DE, Nguyen LK. Dynamic modelling of the PI3K/MTOR signalling network uncovers biphasic dependence of mTORC1 activity on the mTORC2 subunit SIN1. PLoS Comput Biol 2021; 17:e1008513. [PMID: 34529665 PMCID: PMC8478217 DOI: 10.1371/journal.pcbi.1008513] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 09/28/2021] [Accepted: 09/03/2021] [Indexed: 11/18/2022] Open
Abstract
The PI3K/MTOR signalling network regulates a broad array of critical cellular processes, including cell growth, metabolism and autophagy. The mechanistic target of rapamycin (MTOR) kinase functions as a core catalytic subunit in two physically and functionally distinct complexes mTORC1 and mTORC2, which also share other common components including MLST8 (also known as GβL) and DEPTOR. Despite intensive research, how mTORC1 and 2 assembly and activity are coordinated, and how they are functionally linked remain to be fully characterized. This is due in part to the complex network wiring, featuring multiple feedback loops and intricate post-translational modifications. Here, we integrate predictive network modelling, in vitro experiments and -omics data analysis to elucidate the emergent dynamic behaviour of the PI3K/MTOR network. We construct new mechanistic models that encapsulate critical mechanistic details, including mTORC1/2 coordination by MLST8 (de)ubiquitination and the Akt-to-mTORC2 positive feedback loop. Model simulations validated by experimental studies revealed a previously unknown biphasic, threshold-gated dependence of mTORC1 activity on the key mTORC2 subunit SIN1, which is robust against cell-to-cell variation in protein expression. In addition, our integrative analysis demonstrates that ubiquitination of MLST8, which is reversed by OTUD7B, is regulated by IRS1/2. Our results further support the essential role of MLST8 in enabling both mTORC1 and 2’s activity and suggest MLST8 as a viable therapeutic target in breast cancer. Overall, our study reports a new mechanistic model of PI3K/MTOR signalling incorporating MLST8-mediated mTORC1/2 formation and unveils a novel regulatory linkage between mTORC1 and mTORC2. Signalling networks are the key information-processing machineries that underpin the ability of living cells to respond proportionately to extra- (and intra-) cellular cues. The PI3K/MTOR signalling network is one of the most important signalling networks in human cells that regulates cellular response to critical hormones such as insulin; yet our understanding of the network behaviour remains far from complete. Here, we employed a highly integrative approach that combines predictive mathematical modelling, biological experimentation, and data analysis to gain novel systems-level insights into PI3K/MTOR signalling. We constructed new mathematical models of this complex network incorporating important regulatory mechanisms. In contrary to commonly-held views that mTORC2 lies upstream and is a positive regulator of mTORC1, we found that their relationship is highly non-linear and dose dependent. This finding has major implications for anti-mTORC2 therapy as depending on the cellular contexts, inhibiting mTORC2 may either reduce or enhance mTORC1 activation, the latter could inadvertently dampen the effect of mTORC2 blockade. Furthermore, our results demonstrate that MLST8 is required for the assembly and activity of both MTOR complexes and suggest MLST8 is a viable therapeutic target in breast cancer.
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Affiliation(s)
- Milad Ghomlaghi
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, Australia.,Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Guang Yang
- Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Sung-Young Shin
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, Australia.,Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - David E James
- Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Lan K Nguyen
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, Australia.,Biomedicine Discovery Institute, Monash University, Melbourne, Australia
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4
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McKenna M, McGarrigle S, Pidgeon GP. The next generation of PI3K-Akt-mTOR pathway inhibitors in breast cancer cohorts. Biochim Biophys Acta Rev Cancer 2018; 1870:185-197. [PMID: 30318472 DOI: 10.1016/j.bbcan.2018.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/09/2018] [Accepted: 08/15/2018] [Indexed: 12/13/2022]
Abstract
The PI3K/Akt/mTOR pathway plays a role in various oncogenic processes in breast cancer and key pathway aberrations have been identified which drive the different molecular subtypes. Early drugs developed targeting this pathway produced some clinical success but were hampered by pharmacokinetics, tolerability and efficacy problems. This created a need for new PI3K pathway-inhibiting drugs, which would produce more robust results allowing incorporation into treatment regimens for breast cancer patients. In this review, the most promising candidates from the new generation of PI3K-pathway inhibitors is explored, presenting evidence from preclinical and early clinical research, as well as ongoing trials utilising these drugs in breast cancer cohorts. The problems hindering the development of drugs targeting the PI3K pathway are examined, which have created problems for their use as monotherapies. PI3K pathway inhibitor combinations therefore remains a dynamic research area, and their role in combination with immunotherapies and epigenetic therapies is also inspected.
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Affiliation(s)
- Michael McKenna
- Department of Surgery, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, Dublin, Ireland
| | - Sarah McGarrigle
- Department of Surgery, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, Dublin, Ireland
| | - Graham P Pidgeon
- Department of Surgery, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, Dublin, Ireland.
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5
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Watson SS, Dane M, Chin K, Tatarova Z, Liu M, Liby T, Thompson W, Smith R, Nederlof M, Bucher E, Kilburn D, Whitman M, Sudar D, Mills GB, Heiser LM, Jonas O, Gray JW, Korkola JE. Microenvironment-Mediated Mechanisms of Resistance to HER2 Inhibitors Differ between HER2+ Breast Cancer Subtypes. Cell Syst 2018; 6:329-342.e6. [PMID: 29550255 PMCID: PMC5927625 DOI: 10.1016/j.cels.2018.02.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 08/16/2017] [Accepted: 02/02/2018] [Indexed: 01/19/2023]
Abstract
Extrinsic signals are implicated in breast cancer resistance to HER2-targeted tyrosine kinase inhibitors (TKIs). To examine how microenvironmental signals influence resistance, we monitored TKI-treated breast cancer cell lines grown on microenvironment microarrays composed of printed extracellular matrix proteins supplemented with soluble proteins. We tested ~2,500 combinations of 56 soluble and 46 matrix microenvironmental proteins on basal-like HER2+ (HER2E) or luminal-like HER2+ (L-HER2+) cells treated with the TKIs lapatinib or neratinib. In HER2E cells, hepatocyte growth factor, a ligand for MET, induced resistance that could be reversed with crizotinib, an inhibitor of MET. In L-HER2+ cells, neuregulin1-β1 (NRG1β), a ligand for HER3, induced resistance that could be reversed with pertuzumab, an inhibitor of HER2-HER3 heterodimerization. The subtype-specific responses were also observed in 3D cultures and murine xenografts. These results, along with bioinformatic pathway analysis and siRNA knockdown experiments, suggest different mechanisms of resistance specific to each HER2+ subtype: MET signaling for HER2E and HER2-HER3 heterodimerization for L-HER2+ cells.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Breast Neoplasms/drug therapy
- Cell Line, Tumor
- Databases, Genetic
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Enzyme Inhibitors/pharmacology
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, erbB-2/drug effects
- Genes, erbB-2/genetics
- Genes, erbB-2/physiology
- High-Throughput Screening Assays/methods
- Humans
- Lapatinib/pharmacology
- MCF-7 Cells
- Mice
- Protein Kinase Inhibitors/pharmacology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Proto-Oncogene Proteins c-met/antagonists & inhibitors
- Quinazolines/pharmacology
- Quinolines/pharmacology
- Receptor, ErbB-2/antagonists & inhibitors
- Receptor, ErbB-3/antagonists & inhibitors
- Signal Transduction/drug effects
- Tumor Microenvironment/drug effects
- Tumor Microenvironment/genetics
- Tumor Microenvironment/physiology
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Spencer S Watson
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Mark Dane
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Koei Chin
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Zuzana Tatarova
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Moqing Liu
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Tiera Liby
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Wallace Thompson
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Rebecca Smith
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michel Nederlof
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Quantitative Imaging Systems LLC, 1410 NW Kearney Street, #1114, Portland, OR 97209, USA
| | - Elmar Bucher
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - David Kilburn
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Matthew Whitman
- Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Damir Sudar
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Quantitative Imaging Systems LLC, 1410 NW Kearney Street, #1114, Portland, OR 97209, USA
| | - Gordon B Mills
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | - Laura M Heiser
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Oliver Jonas
- Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Joe W Gray
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
| | - James E Korkola
- Department of Biomedical Engineering, Knight Cancer Institute, OHSU Center for Spatial Systems Biomedicine, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
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6
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Qian J, Chen Y, Meng T, Ma L, Meng L, Wang X, Yu T, Zask A, Shen J, Yu K. Molecular regulation of apoptotic machinery and lipid metabolism by mTORC1/mTORC2 dual inhibitors in preclinical models of HER2+/PIK3CAmut breast cancer. Oncotarget 2018; 7:67071-67086. [PMID: 27563814 PMCID: PMC5341858 DOI: 10.18632/oncotarget.11490] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 08/09/2016] [Indexed: 11/25/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a rational target for cancer treatment. While the mTORC1-selective rapalogs have shown significant benefits in the clinic, antitumor response may be further improved by inhibiting both mTORC1 and mTORC2. Herein, we established target profile of a novel mTOR kinase inhibitor (mTOR-KI) MTI-31 and employed it to study new therapeutic mechanism in breast cancer. MTI-31 demonstrated a potent mTOR binding affinity with >5000 fold selectivity over the related PI3K family isoforms. MTI-31 inhibited mTORC1- and mTORC2 function at ≤120 nM in cellular assays or 5 mg/kg orally in tumor-bearing mice. In a panel of breast cancer lines, the antitumor efficacy of MTI-31 was dependent on HER2+ and/or PIK3CAmut (HER2+/PIK3CAmut) status of the tumors and required mTORC2-specific modulation of Bim, MCL-1 and GSK3. Inactivation of Bim or GSK3 each attenuated apoptotic death resulting in mTOR-KI resistance. The antitumor response also required a suppression of lipid metabolism in therapy-sensitive tumors. Treatment with MTI-31 or AZD8055 substantially reduced lipogenesis and acetyl-CoA homeostasis, which was mechanistically linked to a blockade of mTORC2-dependent glucose-to-lipid conversion rate. We also found that the basal levels of carnitine palmitoyltransferase 1A and lipid catabolism were elevated in HER2+/PIK3CAmut breast cells and were inhibited upon mTOR-KI treatment. A CPT1A inhibitor etomoxir mimicked MTI-31 action in selective downregulation of cellular lipid catabolism. Co-treatments with MTI-31 and etomoxir enhanced the suppression of cyclin D1, c-Myc and cell growth in HER2+/PIK3CAmut tumors. These new mechanistic findings provide a rationale for targeting mTORC1 and mTORC2 in HER2+/PIK3CAmut breast cancer.
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Affiliation(s)
- Jianchang Qian
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Yaqing Chen
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Tao Meng
- Department of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Lanping Ma
- Department of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Lanfang Meng
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Xin Wang
- Department of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ting Yu
- Department of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Arie Zask
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jingkang Shen
- Department of Medicinal Chemistry, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ker Yu
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
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7
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Jebali A, Dumaz N. The role of RICTOR downstream of receptor tyrosine kinase in cancers. Mol Cancer 2018; 17:39. [PMID: 29455662 PMCID: PMC5817857 DOI: 10.1186/s12943-018-0794-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 02/01/2018] [Indexed: 12/12/2022] Open
Abstract
The importance of the network defined by phosphatidylinositol-3-kinase (PI3K), AKT and mammalian target of rapamycin (mTOR) downstream of Receptor Tyrosine Kinase (RTK) has been known for many years but the central role of RICTOR (rapamycin-insensitive companion of mTOR) in this pathway is only starting to emerge. RICTOR is critical for mTORC2 (the mammalian target of rapamycin complex 2) kinase activity and as such plays a key role downstream of RTK. Alterations of RICTOR have been identified in a number of cancer cell types and its involvement in tumorigenesis has begun to be unraveled recently. Here, we summarize new research into the biology of RICTOR signaling in cancers focusing on tumors with altered RTK. We show that, as a key signaling node and critical effector of RTKs, RICTOR is becoming a valuable therapeutic target in cancer with altered RTK.
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Affiliation(s)
- Ahlem Jebali
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint Louis, F-75010, 1 avenue Claude Vellefaux, 75475 Paris cedex 10, Paris, France.,Univ Paris Diderot, Sorbonne Paris Cité, UMR 976, F-75010, Paris, France
| | - Nicolas Dumaz
- INSERM, U976, Centre de Recherche sur la Peau, Hôpital Saint Louis, F-75010, 1 avenue Claude Vellefaux, 75475 Paris cedex 10, Paris, France. .,Univ Paris Diderot, Sorbonne Paris Cité, UMR 976, F-75010, Paris, France.
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8
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Chen Y, Qian J, He Q, Zhao H, Toral-Barza L, Shi C, Zhang X, Wu J, Yu K. mTOR complex-2 stimulates acetyl-CoA and de novo lipogenesis through ATP citrate lyase in HER2/PIK3CA-hyperactive breast cancer. Oncotarget 2018; 7:25224-40. [PMID: 27015560 PMCID: PMC5041899 DOI: 10.18632/oncotarget.8279] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 03/05/2016] [Indexed: 12/22/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a major regulator of cell growth and is frequently dysregulated in cancer. While mTOR complex-1 (mTORC1) is a validated cancer target, the role of mTOR complex-2 (mTORC2) remains less defined. Here, we reveal mTORC2 as a critical regulator of breast cancer metabolism. We showed that hyperphosphorylation in ATP citrate lyase (ACL) occurs frequently in human breast tumors and correlates well with HER2+ and/or PIK3CA-mutant (HER2+/PIK3CAmut) status in breast tumor cell lines. In HER2+/PIK3CAmut cells, mTORC2 controls Ser-455 phosphorylation of ACL thereby promoting acetyl-CoA production, de novo lipogenesis and mitochondrial physiology, all of which were inhibited by an mTORC1/mTORC2 kinase inhibitor (mTOR-KI) or cellular depletion of mTORC2 or ACL. mTOR-KI but not rapamycin blocked the IGF-1-induced ACL phosphorylation and glucose to lipid conversion. Depletion of mTORC2 but not mTORC1 specifically inhibited the ACL-dependent acetyl-CoA production. In the HER2+/PIK3CAmut MDA361, MDA453, BT-474 and T47D cells, depletion of mTORC2 or ACL led to growth inhibition and mitochondrial hyperpolarization, which were partially rescued by an alternate source of acetyl-CoA. These same changes were not apparent in mTORC2- or ACL-depleted HER2-/PIK3CAwt MDA231 and HCC1806 cells, highlighting a differential dependence of mTORC2-ACL for survival in these two cell types. Moreover, ACL Ser-455 mutants S455E (phosphomimetic) and S455A (non-phosphorylatable) each increased or decreased, respectively, the acetyl-CoA production, mitochondrial homeostasis and survival in ACL-depleted MDA453 cells. These studies define a new and rapamycin-resistant mechanism of mTORC2-ACL in lipogenesis and acetyl-CoA biology and provide a rationale for targeting of mTORC1 and mTORC2 in HER2+/PIK3CAmut breast cancer.
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Affiliation(s)
- Yaqing Chen
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Jianchang Qian
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Qun He
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Hui Zhao
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | | | - Celine Shi
- Oncology Research, Pfizer Pharmaceuticals, Pearl River, NY, USA
| | - Xuesai Zhang
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
| | - Jiang Wu
- Oncology Research, Pfizer Pharmaceuticals, Pearl River, NY, USA
| | - Ker Yu
- Department of Pharmacology, Fudan University School of Pharmacy, Shanghai, China
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9
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Kar A, Gutierrez-Hartmann A. ESE-1/ELF3 mRNA expression associates with poor survival outcomes in HER2 + breast cancer patients and is critical for tumorigenesis in HER2 + breast cancer cells. Oncotarget 2017; 8:69622-69640. [PMID: 29050229 PMCID: PMC5642504 DOI: 10.18632/oncotarget.18710] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/23/2017] [Indexed: 12/25/2022] Open
Abstract
ESE-1/Elf3 and HER2 appear to establish a positive feedback regulatory loop, but the precise role of ESE-1 in HER2+ breast tumorigenesis remains unknown. Analyzing public repositories, we found that luminal B and HER2 subtype patients with high ESE-1 mRNA levels displayed worse relapse free survival. We stably knocked down ESE-1 in HER2+ luminal B BT474 cells and HER2 subtype SKBR3 cells, which resulted in decreased cell proliferation, colony formation, and anchorage-independent growth in vitro. Stable ESE-1 knockdown inhibited HER2-dependent signaling in BT474 cells and inhibited mTOR activation in SKBR3 cells, but reduced Akt signaling in both cell types. Expression of a constitutively-active Myr-Akt partially rescued the anti-proliferative effect of ESE-1 knockdown in both cell lines. Furthermore, ESE-1 knockdown inhibited cyclin D1, resulting in a G1 delay in both cell lines. Finally, ESE-1 knockdown completely inhibited BT474 cell xenograft tumors in NOD/SCID female mice, which correlated with reduced in vitro tumorsphere formation. Taken together, these results reveal the ESE-1 controls transformation via distinct upstream signaling mechanisms in SKBR3 and BT474 cells, which ultimately impinge on Akt and cyclin D1 in both cell types to regulate cell proliferation. Particularly significant is that ESE-1 controls tumorigenesis and is associated with worse clinical outcomes in HER2 breast cancer.
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Affiliation(s)
- Adwitiya Kar
- Cancer Biology Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Arthur Gutierrez-Hartmann
- Cancer Biology Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Biochemistry & Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.,Program in Molecular Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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10
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HER-3 targeting alters the dimerization pattern of ErbB protein family members in breast carcinomas. Oncotarget 2016; 7:5576-97. [PMID: 26716646 PMCID: PMC4868707 DOI: 10.18632/oncotarget.6762] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/22/2015] [Indexed: 01/06/2023] Open
Abstract
Breast carcinogenesis is a multi-step process in which membrane receptor tyrosine kinases are crucial participants. Lots of research has been done on epidermal growth factor receptor (EGFR) and HER-2 with important clinical results. However, breast cancer patients present intrinsic or acquired resistance to available HER-2-directed therapies, mainly due to HER-3. Using new techniques, such as proximity ligation assay, herein we evaluate the dimerization pattern of HER-3 and the importance of context-dependent dimer formation between HER-3 and other HER protein family members. Additionally, we show that the efficacy of novel HER-3 targeting agents can be better predicted in certain breast cancer patient sub-groups based on the dimerization pattern of HER protein family members. Moreover, this model was also evaluated and reproduced in human paraffin-embedded breast cancer tissues.
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11
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Ong PS, Wang LZ, Dai X, Tseng SH, Loo SJ, Sethi G. Judicious Toggling of mTOR Activity to Combat Insulin Resistance and Cancer: Current Evidence and Perspectives. Front Pharmacol 2016; 7:395. [PMID: 27826244 PMCID: PMC5079084 DOI: 10.3389/fphar.2016.00395] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/07/2016] [Indexed: 12/16/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR), via its two distinct multiprotein complexes, mTORC1, and mTORC2, plays a central role in the regulation of cellular growth, metabolism, and migration. A dysregulation of the mTOR pathway has in turn been implicated in several pathological conditions including insulin resistance and cancer. Overactivation of mTORC1 and disruption of mTORC2 function have been reported to induce insulin resistance. On the other hand, aberrant mTORC1 and mTORC2 signaling via either genetic alterations or increased expression of proteins regulating mTOR and its downstream targets have contributed to cancer development. These underlined the attractiveness of mTOR as a therapeutic target to overcome both insulin resistance and cancer. This review summarizes the evidence supporting the notion of intermittent, low dose rapamycin for treating insulin resistance. It further highlights recent data on the continuous use of high dose rapamycin analogs and related second generation mTOR inhibitors for cancer eradication, for overcoming chemoresistance and for tumor stem cell suppression. Within these contexts, the potential challenges associated with the use of mTOR inhibitors are also discussed.
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Affiliation(s)
- Pei Shi Ong
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Louis Z Wang
- Department of Pharmacy, Faculty of Science, National University of SingaporeSingapore, Singapore; Department of Pharmacology, Yong Loo Lin School of Medicine, National University of SingaporeSingapore, Singapore
| | - Xiaoyun Dai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
| | - Sheng Hsuan Tseng
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Shang Jun Loo
- Department of Pharmacy, Faculty of Science, National University of Singapore Singapore, Singapore
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore Singapore, Singapore
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12
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Okada T, Lee AY, Qin LX, Agaram N, Mimae T, Shen Y, O'Connor R, López-Lago MA, Craig A, Miller ML, Agius P, Molinelli E, Socci ND, Crago AM, Shima F, Sander C, Singer S. Integrin-α10 Dependency Identifies RAC and RICTOR as Therapeutic Targets in High-Grade Myxofibrosarcoma. Cancer Discov 2016; 6:1148-1165. [PMID: 27577794 PMCID: PMC5050162 DOI: 10.1158/2159-8290.cd-15-1481] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 08/25/2016] [Indexed: 12/31/2022]
Abstract
Myxofibrosarcoma is a common mesenchymal malignancy with complex genomics and heterogeneous clinical outcomes. Through gene-expression profiling of 64 primary high-grade myxofibrosarcomas, we defined an expression signature associated with clinical outcome. The gene most significantly associated with disease-specific death and distant metastasis was ITGA10 (integrin-α10). Functional studies revealed that myxofibrosarcoma cells strongly depended on integrin-α10, whereas normal mesenchymal cells did not. Integrin-α10 transmitted its tumor-specific signal via TRIO and RICTOR, two oncoproteins that are frequently co-overexpressed through gene amplification on chromosome 5p. TRIO and RICTOR activated RAC/PAK and AKT/mTOR to promote sarcoma cell survival. Inhibition of these proteins with EHop-016 (RAC inhibitor) and INK128 (mTOR inhibitor) had antitumor effects in tumor-derived cell lines and mouse xenografts, and combining the drugs enhanced the effects. Our results demonstrate the importance of integrin-α10/TRIO/RICTOR signaling for driving myxofibrosarcoma progression and provide the basis for promising targeted treatment strategies for patients with high-risk disease. SIGNIFICANCE Identifying the molecular pathogenesis for myxofibrosarcoma progression has proven challenging given the highly complex genomic alterations in this tumor type. We found that integrin-α10 promotes tumor cell survival through activation of TRIO-RAC-RICTOR-mTOR signaling, and that inhibitors of RAC and mTOR have antitumor effects in vivo, thus identifying a potential treatment strategy for patients with high-risk myxofibrosarcoma. Cancer Discov; 6(10); 1148-65. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1069.
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Affiliation(s)
- Tomoyo Okada
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - Ann Y Lee
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Li-Xuan Qin
- Department of Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Narasimhan Agaram
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Takahiro Mimae
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Yawei Shen
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Rachael O'Connor
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Miguel A López-Lago
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Amanda Craig
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Martin L Miller
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Phaedra Agius
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Evan Molinelli
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nicholas D Socci
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Aimee M Crago
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Surgery, Weill Cornell Medical College, New York, New York
| | - Fumi Shima
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Chris Sander
- Computational Biology Center, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Samuel Singer
- Sarcoma Biology Laboratory, Sarcoma Disease Management Program, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, New York. Department of Surgery, Weill Cornell Medical College, New York, New York.
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13
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Capparelli C, Rosenbaum S, Berger AC, Aplin AE. Fibroblast-derived neuregulin 1 promotes compensatory ErbB3 receptor signaling in mutant BRAF melanoma. J Biol Chem 2015; 290:24267-77. [PMID: 26269601 DOI: 10.1074/jbc.m115.657270] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Indexed: 01/07/2023] Open
Abstract
Rapidly accelerated fibrosarcoma (RAF) inhibitors are first-line treatments for patients harboring V600E/K mutant BRAF melanoma. Although RAF inhibitors produce high response rates, the degree of tumor regression is heterogeneous. Compensatory/adaptive responses to targeted inhibitors are frequently initiated by the activation of growth factor receptor tyrosine kinases, including ErbB3, and factors from the tumor microenvironment may play an important role. We have shown previously that mutant v-raf murine sarcoma viral oncogene homolog B1 (BRAF) melanoma cells have enhanced activation of ErbB3 following RAF inhibition. However, the source of neuregulin 1 (NRG1), the ligand for ErbB3, is unknown. In this study, we demonstrate that NRG1 is highly expressed by dermal fibroblasts and cancer-associated fibroblasts (CAFs) isolated from mutant BRAF melanomas. Conditioned medium from fibroblasts and CAFs enhanced ErbB3 pathway activation and limited RAF inhibitor cytotoxicity in V600 mutant BRAF-harboring melanomas. Targeting the ErbB3/ErbB2 pathway partially reversed the protective effects of fibroblast/CAF-derived NRG1 on cell growth properties of RAF inhibitor-treated melanoma cells. These findings support the idea that NRG1, acting in a paracrine manner, promotes resistance to RAF inhibitors and emphasize that targeting the ErbB3/ErbB2 pathway will likely improve the efficacy of RAF inhibitors for mutant BRAF melanoma patients.
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Affiliation(s)
| | - Sheera Rosenbaum
- From the Department of Cancer Biology, Sidney Kimmel Cancer Center, and
| | - Adam C Berger
- Department of Surgery, Division of General Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Andrew E Aplin
- From the Department of Cancer Biology, Sidney Kimmel Cancer Center, and
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Menon R, Panwar B, Eksi R, Kleer C, Guan Y, Omenn GS. Computational Inferences of the Functions of Alternative/Noncanonical Splice Isoforms Specific to HER2+/ER-/PR- Breast Cancers, a Chromosome 17 C-HPP Study. J Proteome Res 2015; 14:3519-29. [PMID: 26147891 DOI: 10.1021/acs.jproteome.5b00498] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study was conducted as a part of the Chromosome-Centric Human Proteome Project (C-HPP) of the Human Proteome Organization. The main objective is to identify and evaluate functionality of a set of specific noncanonical isoforms expressed in HER2-neu positive, estrogen receptor negative (ER-), and progesterone receptor negative (PR-) breast cancers (HER2+/ER-/PR- BC), an aggressive subtype of breast cancers that cause significant morbidity and mortality. We identified 11 alternative splice isoforms that were differentially expressed in HER2+/ER-/PR- BC compared to normal mammary, triple negative breast cancer and triple positive breast cancer tissues (HER2+/ER+/PR+). We used a stringent criterion that differentially expressed noncanonical isoforms (adjusted p value < 0.05) and have to be expressed in all replicates of HER2+/ER-/PR- BC samples, and the trend in differential expression (up or down) is the same in all comparisons. Of the 11 protein isoforms, six were overexpressed in HER2+/ER-/PR- BC. We explored possible functional roles of these six proteins using several complementary computational tools. Biological processes including cell cycle events and glycolysis were linked to four of these proteins. For example, glycolysis was the top ranking functional process for DMXL2 isoform 3, with a fold change of 27 compared to just two for the canonical protein. No previous reports link DMXL2 with any metabolic processes; the canonical protein is known to participate in signaling pathways. Our results clearly indicate distinct functions for the six overexpressed alternative splice isoforms, and these functions could be specific to HER2+/ER-/PR- tumor progression. Further detailed analysis is warranted as these proteins could be explored as potential biomarkers and therapeutic targets for HER2+/ER-/PR- BC patients.
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Affiliation(s)
- Rajasree Menon
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
| | - Bharat Panwar
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
| | - Ridvan Eksi
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
| | - Celina Kleer
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
| | - Yuanfang Guan
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
| | - Gilbert S Omenn
- University of Michigan , 100 Washtenaw Avenue, Room 2044B, Palmer Commons, Ann Arbor, Michigan 48109, United States
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15
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Pan B, Wang R, Huang Y, Garfield D, Zhang J, Chen H. HGF and NRG1 protein expression are not poor prognostic markers in surgically resected lung adenocarcinoma. Onco Targets Ther 2015; 8:1185-91. [PMID: 26045672 PMCID: PMC4448923 DOI: 10.2147/ott.s78116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose Although over-expression of hepatocyte growth factor (HGF) and neuregulin-1 (NRG1) are important mechanisms involved in acquired drug-resistance in many cancers, few reports have evaluated their clinicopathologic features and prognostic significance. The aim of our study was to investigate protein expressions of HGF and NRG1 in lung adenocarcinomas and their association with clinicopathologic parameters, oncogenic mutations, and the prognosis. Methods HGF and NRG1 protein tumor/stroma expressions were evaluated by immunohistochemistry (IHC) in 115 surgically resected lung adenocarcinomas and were correlated with clinicopathologic and molecular variables including tumor size, tumor node metastasis stage, differentiation, oncogenic mutations (EGFR, KRAS, HER2, BRAF) and ALK fusions, relapse-free survival, and overall survival. Results Positive IHC HGF tumor and stroma staining were found in 49 (42.61%) and 12 (10.43%) cases, respectively, while positive IHC NRG1 tumor and stroma staining were found in 56 (48.70%) and eleven (9.57%) cases, respectively. Dual positive IHC HGF and NRG1 tumor staining was 12.17%. EML4-ALK fusion more significantly existed in HGF-tumor positive samples (P=0.03), positive NRG1 protein stroma expression was significantly associated with male sex (P=0.04), while HGF and NRG1 dual tumor-positive mainly existed in the tumor size >3 cm group (P=0.0231). No significant clinically prognostic difference was found between patients with HGF/NRG1-positive expression and those with HGF/NRG1-negative expression. Conclusion This study represents the first comprehensive analysis of HGF and NRG1 tumor and stroma expressions in patients with surgically resected lung adenocarcinomas. Our molecular data, in conjunction with clinical and pathological features, as well as their effects on survival indicated to us that patients with HGF- and NRG1-negative expression tended to have better survival, but these results probably did not warrant these markers to be indicators of poor prognosis.
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Affiliation(s)
- Bin Pan
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Rui Wang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Yangle Huang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - David Garfield
- University of Colorado Comprehensive Cancer Center, Aurora, CO, USA
| | - Jie Zhang
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Haiquan Chen
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, People's Republic of China ; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
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16
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Jiang SJ, Wang S. Dual targeting of mTORC1 and mTORC2 by INK-128 potently inhibits human prostate cancer cell growth in vitro and in vivo. Tumour Biol 2015; 36:8177-84. [PMID: 25990456 DOI: 10.1007/s13277-015-3536-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 05/05/2015] [Indexed: 10/23/2022] Open
Abstract
Both mammalian target of rapamycin (mTOR) complexes 1 and 2 (mTORC1/2) are often over-activated in prostate cancer cells and are associated with cancer progression. In the current study, we evaluated the potential anti-prostate cancer activity of INK-128, an ATP-competitive mTORC1/2 dual inhibitor, both in vitro and in vivo. Our results showed that INK-128 exerted potent anti-proliferative activity in established (PC-3 and LNCaP lines) and primary (patient-derived) human prostate cancer cells by inducing cell apoptosis. The latter was evidenced by increase of annexin V percentage, formation of cytoplasmic histone-associated DNA fragments, and cleavage of caspase-3. INK-128-induced prostate cancer cell apoptosis and cytotoxicity were alleviated upon pretreatment of cells with the pan-caspase inhibitor z-VAD-FMK or the specific caspase-3 inhibitor z-DVED-FMK. At the molecular level, INK-18 blocked mTORC1/2 activation in PC-3 cells and LNCaP cells and downregulated mTOR-regulated genes including cyclin D1, hypoxia-inducible factor 1α (HIF-1α), and HIF-2α. ERK-MAPK activation and androgen receptor expression were, however, not affected by INK-128 treatment. In vivo, oral administration of INK-128 significantly inhibited growth of PC-3 xenografts in nude mice. The preclinical results of this study suggest that INK-128 could be further investigated as a promising anti-prostate cancer agent.
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Affiliation(s)
- Shang-Jun Jiang
- The Department of Urinary Surgery, The People's Hospital of Fuyang, 4 Gui'hua Road, Fuyang City, Zhejiang Province, 311400, China.
| | - Shuo Wang
- The Department of Urinary Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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17
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Dey N, Williams C, Leyland-Jones B, De P. A critical role for HER3 in HER2-amplified and non-amplified breast cancers: function of a kinase-dead RTK. Am J Transl Res 2015; 7:733-750. [PMID: 26064441 PMCID: PMC4455348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/11/2015] [Indexed: 06/04/2023]
Abstract
ERBB3/HER3 is the most intriguing RTK by virtue of its ability to transduce multiple cytosolic signals for the proliferation and growth of tumor cells in spite of being a "kinase dead" receptor that binds to its true ligand, heregulin. Although other members of the HER3 family like EGFR and HER2 have long been recognized to be associated with breast tumorigenesis and studied because of their predictive and prognostic value, the significance of HER3 as an irrefutable component of HER family signalosome is a relatively new development. The recent understanding of signals originating from the oncogenic partnership of HER3 with HER2 in the context of HER2 amplification/overexpression showed the critical clinical value for the treatment of HER2+BC. The downstream signaling cascade (included but not limited to the PI3K signaling) associated with signals originating from HER2:HER3 dimers play a vital role in the tumorigenesis, drug-resistance and tumor progression of HER2+BC. The upregulation of HER3 activity provides an alternate "escape route" via which tumor cells bypass either the inhibition of the HER family RTKs or the inhibition of the downstream PI3K-AKT-mTOR signaling pathway. By understanding the signaling that provides this "escape route" for these tumor cells treated with a targeted therapy (HER2 inhibitors or inhibitors of downstream PI3K-AKT-mTOR signaling pathway), we are just beginning to appreciate the prognostic value of HER3 in breast cancer. In this review, we will discuss the relevance of HER3 signaling in the context of, (1) downstream oncogenic signals and (2) therapeutic options in HER2 amplified BC.
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Affiliation(s)
- Nandini Dey
- Department of Molecular and Experimental Medicine, Avera Cancer InstituteSioux Falls, SD
- Department of Internal Medicine, SSOM, University of South DakotaSD
| | - Casey Williams
- Department of Molecular and Experimental Medicine, Avera Cancer InstituteSioux Falls, SD
- Department of Internal Medicine, SSOM, University of South DakotaSD
| | - Brain Leyland-Jones
- Department of Molecular and Experimental Medicine, Avera Cancer InstituteSioux Falls, SD
- Department of Internal Medicine, SSOM, University of South DakotaSD
| | - Pradip De
- Department of Molecular and Experimental Medicine, Avera Cancer InstituteSioux Falls, SD
- Department of Internal Medicine, SSOM, University of South DakotaSD
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Lou HZ, Weng XC, Pan HM, Pan Q, Sun P, Liu LL, Chen B. The novel mTORC1/2 dual inhibitor INK-128 suppresses survival and proliferation of primary and transformed human pancreatic cancer cells. Biochem Biophys Res Commun 2014; 450:973-8. [PMID: 24971544 DOI: 10.1016/j.bbrc.2014.06.081] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/17/2014] [Indexed: 11/25/2022]
Abstract
Pancreatic cancer has one of worst prognosis among all human malignancies around the world, the development of novel and more efficient anti-cancer agents against this disease is urgent. In the current study, we tested the potential effect of INK-128, a novel mammalian target of rapamycin (mTOR) complex 1 and 2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells in vitro. Our results demonstrated that INK-128 concentration- and time-dependently inhibited the survival and growth of pancreatic cancer cells (both primary cells and transformed cells). INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. Further, INK-128 dramatically inhibited phosphorylation of 4E-binding protein 1 (4E-BP1), ribosomal S6 kinase 1 (S6K1) and Akt at Ser 473 in pancreatic cancer cells. Meanwhile, it downregulated cyclin D1 expression and caused cell cycle arrest. Finally, we found that a low concentration of INK-128 significantly increased the sensitivity of pancreatic cancer cells to gemcitabine. Together, our in vitro results suggest that INK-128 might be further investigated as a novel anti-cancer agent or chemo-adjuvant for pancreatic cancer treatment.
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Affiliation(s)
- Hai-Zhou Lou
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Xiao-Chuan Weng
- Department of Anesthesiology, Hangzhou Xia-sha Hospital, Hangzhou 310018, China
| | - Hong-Ming Pan
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Qin Pan
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Peng Sun
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Li-Li Liu
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Bin Chen
- Department of Hepatopancreatobiliary Surgery, First People's Hospital of Hangzhou, Hangzhou 310006, China.
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