1
|
An Insight into GPCR and G-Proteins as Cancer Drivers. Cells 2021; 10:cells10123288. [PMID: 34943797 PMCID: PMC8699078 DOI: 10.3390/cells10123288] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are the largest family of cell surface signaling receptors known to play a crucial role in various physiological functions, including tumor growth and metastasis. Various molecules such as hormones, lipids, peptides, and neurotransmitters activate GPCRs that enable the coupling of these receptors to highly specialized transducer proteins, called G-proteins, and initiate multiple signaling pathways. Integration of these intricate networks of signaling cascades leads to numerous biochemical responses involved in diverse pathophysiological activities, including cancer development. While several studies indicate the role of GPCRs in controlling various aspects of cancer progression such as tumor growth, invasion, migration, survival, and metastasis through its aberrant overexpression, mutations, or increased release of agonists, the explicit mechanisms of the involvement of GPCRs in cancer progression is still puzzling. This review provides an insight into the various responses mediated by GPCRs in the development of cancers, the molecular mechanisms involved and the novel pharmacological approaches currently preferred for the treatment of cancer. Thus, these findings extend the knowledge of GPCRs in cancer cells and help in the identification of therapeutics for cancer patients.
Collapse
|
2
|
Moody TW, Ramos-Alvarez I, Jensen RT. Bombesin, endothelin, neurotensin and pituitary adenylate cyclase activating polypeptide cause tyrosine phosphorylation of receptor tyrosine kinases. Peptides 2021; 137:170480. [PMID: 33385499 DOI: 10.1016/j.peptides.2020.170480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022]
Abstract
Numerous peptides including bombesin (BB), endothelin (ET), neurotensin (NTS) and pituitary adenylate cyclase-activating polypeptide (PACAP) are growth factors for lung cancer cells. The peptides bind to G protein-coupled receptors (GPCRs) resulting in elevated cAMP and/or phosphatidylinositol (PI) turnover. In contrast, growth factors such as epidermal growth factor (EGF) or neuregulin (NRG)-1 bind to receptor tyrosine kinases (RTKs) such as the EGFR or HER3, increasing tyrosine kinase activity, resulting in the phosphorylation of protein substrates such as PI3K or phospholipase (PL)C. Peptide GPCRs can transactivate numerous RTKs, especially members of the EGFR/HER family resulting in increased phosphorylation of ERK, leading to cellular proliferation or increased phosphorylation of AKT, leading to cellular survival. GRCR antagonists and tyrosine kinase inhibitors are useful agents to prevent RTK transactivation and inhibit proliferation of cancer cells.
Collapse
Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Institutes of Health, National Cancer Institute, Center for Cancer Training, Bethesda, MD, 20892, USA.
| | - Irene Ramos-Alvarez
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
| | - Robert T Jensen
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
| |
Collapse
|
3
|
Dong L, Zhang B, Wu L, Shang Z, Liu S, Jiang X, Wang H, Fan L, Zhang Y, Xiao H. Proteomics Analysis of Cellular BRS3 Receptor Activation Reveals Potential Mechanism for Signal Transduction and Cell Proliferation. J Proteome Res 2020; 19:1513-1521. [PMID: 32091899 DOI: 10.1021/acs.jproteome.9b00760] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bombesin-like receptor 3 (BRS3), an orphan G protein-coupled receptor (GPCR), plays important roles in our biological system while the exact mechanisms behind it are less known. To get insights of the biological effects upon BRS3 activation, we utilized quantitative proteomics approach to explore the dynamic protein profiling during the stimulation by its ligand. At different time points after stimulation with BRS3 surrogate agonist, the protein profiling in BRS3 overexpressed HEK 293 cells BRS3 (HEK 293-BRS3) was analyzed by nano-LC-MS/MS. In total, 1593 cellular proteins were confidently identified and quantified, including 146 proteins dysregulated at multiple time points and 319 proteins only altered at one time point. Data analysis indicated that BRS3 activation could regulate cell death, survival, and protein synthesis, particularly mRNA translation. Key signaling pathways were revealed for BRS3 signal transduction. In particular, 21 of our identified proteins are involved in the rapamycin (mTOR) signaling pathway. The promotion of mTOR was further confirmed through monitoring its indicative targets upon BRS3 activation. Upon the inhibition of mTOR by rapamycin, cell proliferation was dramatically reversed. Our proteomics data collectively demonstrate that BRS3 activation will lead to cascades of signal transduction and promote cell proliferation. The developed strategy might be utilized to discover the roles of other GPCRs and improve our understanding of their unknown functions.
Collapse
Affiliation(s)
- Lijie Dong
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Baohui Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lehao Wu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhi Shang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Sha Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaoteng Jiang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huiyu Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liuyin Fan
- Student Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan Zhang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hua Xiao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| |
Collapse
|
4
|
Lee L, Ramos-Alvarez I, Moody TW, Mantey SA, Jensen RT. Neuropeptide bombesin receptor activation stimulates growth of lung cancer cells through HER3 with a MAPK-dependent mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118625. [PMID: 31862538 DOI: 10.1016/j.bbamcr.2019.118625] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/15/2019] [Accepted: 12/14/2019] [Indexed: 01/28/2023]
Abstract
Despite recent advances in treatment of non-small cell lung cancer (NSCLC), prognosis still remains poor and new therapeutic approaches are needed. Studies demonstrate the importance of the EGFR/HER-receptor family in NSCLC growth, as well as that of other tumors. Recently, HER3 is receiving increased attention because of its role in drug resistance and aggressive growth. Activation of overexpressed G-protein-coupled receptors (GPCR) can also initiate growth by transactivating EGFR/HER-family members. GPCR transactivation of EGFR has been extensively studied, but little is known of its ability to transactivate other EGFR/HER-members, especially HER3. To address this, we studied the ability of bombesin receptor (BnR) activation to transactivate all EGFR/HER-family members and their principal downstream signaling cascades, the PI3K/Akt- and MAPK/ERK-pathways, in human NSCLC cell-lines. In all three cell-lines studied, which possessed EGFR, HER2 and HER3, Bn rapidly transactivated EGFR, HER2 and HER3, as well as Akt and ERK. Immunoprecipitation studies revealed Bn-induced formation of both HER3/EGFR- and HER3/HER2-heterodimers. Specific EGFR/HER3 antibodies or siRNA-knockdown of EGFR and HER3, demonstrated Bn-stimulated activation of EGFR/HER members is initially through HER3, not EGFR. In addition, specific inhibition of HER3, HER2 or MAPK, abolished Bn-stimulated cell-growth, while neither EGFR nor Akt inhibition had an effect. These results show HER3 transactivation mediates all growth effects of BnR activation through MAPK. These results raise the possibility that targeting HER3 alone or with GPCR activation and its signal cascades, may be a novel therapeutic approach in NSCLC. This is especially relevant with the recent development of HER3-blocking antibodies.
Collapse
Affiliation(s)
- Lingaku Lee
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of the Director, Bethesda, MD 20892, USA
| | - Samuel A Mantey
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Robert T Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
5
|
Wang P, Zhang L, Li H, Wang Y, Zhang S, Liu Z. Characterization of GRP as a functional neuropeptide in basal chordate amphioxus. Int J Biol Macromol 2019; 142:384-394. [PMID: 31593737 DOI: 10.1016/j.ijbiomac.2019.09.109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 09/12/2019] [Accepted: 09/14/2019] [Indexed: 01/14/2023]
Abstract
Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates, whose regulation of endocrine system remains ambiguous. Here we clearly demonstrated the existence of a functional GRP neuropeptide in amphioxus, which was able to interact with GRP receptor, activate both PKC and PKA pathways, increase gh, igf, and vegf expression. We also showed that the transcription level of amphioxus grp was affected by temperature and light, indicating the role of this gene in the regulation of energy balance and circadian rhythms. In addition, the expression of the amphioxus grp was detected in cerebral vesicle that has been proposed to be the homologous organ of vertebrate brain. These data collectively suggested that a functional GRP neuropeptide had already emerged in amphioxus, which provided insights into the evolutionary origin of GRP in chordate and the functional homology between the cerebral vesicle and vertebrate brain.
Collapse
Affiliation(s)
- Peng Wang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Liping Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Haoyi Li
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Yunsheng Wang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266003, China
| | - Zhenhui Liu
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266003, China.
| |
Collapse
|
6
|
Moody TW. Peptide receptors as cancer drug targets. Ann N Y Acad Sci 2019; 1455:141-148. [PMID: 31074514 DOI: 10.1111/nyas.14100] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/08/2019] [Accepted: 03/26/2019] [Indexed: 12/18/2022]
Abstract
Neuropeptides function as neuromodulators in the brain, whereby they are released in a paracrine manner and activate G protein-coupled receptors (GPCRs) in adjacent cells. Because neuropeptides are made in, and secreted from, cancer cells, then bind to cell surface receptors, they function in an autocrine manner. Bombesin (BB)-like peptides synthesized by neuroendocrine tumor small cell lung cancer (SCLC) bind to BB receptors (BBRs), causing phosphatidylinositol turnover and phosphorylation of extracellular signal-regulated kinase (ERK). Phosphorylated ERK enters the nucleus and alters gene expression of SCLC cells, stimulating growth. Vasoactive intestinal peptide (VIP) addition to SCLC cells increases their release rate of BB-like peptides via activation of VIP receptors (VIPR), leading to activation of adenylyl cyclase and subsequent elevation of cAMP. Protein kinase A is then stimulated, leading to phosphorylation of cyclic AMP response element binding protein (CREB), which alters gene expression and stimulates proliferation. The growth of SCLC is inhibited by BBR and VIPR antagonists. This review will focus on how GPCRs for VIP and BB are molecular targets for early detection and treatment of cancer.
Collapse
Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, Center for Cancer Training, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
7
|
Shirey KA, Sunday ME, Lai W, Patel M, Blanco JCG, Cuttitta F, Vogel SN. Novel role of gastrin releasing peptide-mediated signaling in the host response to influenza infection. Mucosal Immunol 2019; 12:223-231. [PMID: 30327535 PMCID: PMC6301097 DOI: 10.1038/s41385-018-0081-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/19/2018] [Accepted: 08/08/2018] [Indexed: 02/04/2023]
Abstract
Gastrin-releasing peptide (GRP) is an evolutionarily well-conserved neuropeptide that was originally recognized for its ability to mediate gastric acid secretion in the gut. More recently, however, GRP has been implicated in pulmonary lung inflammatory diseases including bronchopulmonary dysplasia, chronic obstructive pulmonary disease, emphysema, and others. Antagonizing GRP or its receptor mitigated lethality associated with the onset of viral pneumonia in a well-characterized mouse model of influenza. In mice treated therapeutically with the small-molecule GRP inhibitor, NSC77427, increased survival was accompanied by decreased numbers of GRP-producing pulmonary neuroendocrine cells, improved lung histopathology, and suppressed cytokine gene expression. In addition, in vitro studies in macrophages indicate that GRP synergizes with the prototype TLR4 agonist, lipopolysaccharide, to induce cytokine gene expression. Thus, these findings reveal that GRP is a previously unidentified mediator of influenza-induced inflammatory disease that is a potentially novel target for therapeutic intervention.
Collapse
Affiliation(s)
- Kari Ann Shirey
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
| | - Mary E. Sunday
- Dept. of Pathology, Duke University Medical Center, Durham, NC USA 27710
| | - Wendy Lai
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
| | - Mira Patel
- Sigmovir Biosystems, Inc., Rockville, MD USA 20850
| | | | - Frank Cuttitta
- Mouse Cancer Genetics Program, National Cancer Institute, NIH, Frederick, MD USA 21702
| | - Stefanie N. Vogel
- Dept. of Microbiology and Immunology, Univ. of Maryland, School of Medicine, Baltimore, MD USA 21201
| |
Collapse
|
8
|
Moreno P, Mantey SA, Lee SH, Ramos-Álvarez I, Moody TW, Jensen RT. A possible new target in lung-cancer cells: The orphan receptor, bombesin receptor subtype-3. Peptides 2018; 101:213-226. [PMID: 29410320 PMCID: PMC6159918 DOI: 10.1016/j.peptides.2018.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/27/2018] [Accepted: 01/31/2018] [Indexed: 12/11/2022]
Abstract
Human bombesin receptors, GRPR and NMBR, are two of the most frequently overexpressed G-protein-coupled-receptors by lung-cancers. Recently, GRPR/NMBR are receiving considerable attention because they act as growth factor receptors often in an autocrine manner in different lung-cancers, affect tumor angiogenesis, their inhibition increases the cytotoxic potency of tyrosine-kinase inhibitors reducing lung-cancer cellular resistance/survival and their overexpression can be used for sensitive tumor localization as well as to target cytotoxic agents to the cancer. The orphan BRS-3-receptor, because of homology is classified as a bombesin receptor but has received little attention, despite the fact that it is also reported in a number of studies in lung-cancer cells and has growth effects in these cells. To address its potential importance, in this study, we examined the frequency/relative quantitative expression of human BRS-3 compared to GRPR/NMBR and the effects of its activation on cell-signaling/growth in 13 different human lung-cancer cell-lines. Our results showed that BRS-3 receptor is expressed in 92% of the cell-lines and that it is functional in these cells, because its activation stimulates phospholipase-C with breakdown of phosphoinositides and changes in cytosolic calcium, stimulates ERK/MAPK and stimulates cell growth by EGFR transactivation in some, but not all, the lung-cancer cell-lines. These results suggest that human BRS-3, similar to GRPR/NMBR, is frequently ectopically-expressed by lung-cancer cells in which, it is functional, affecting cell signaling/growth. These results suggest that similar to GRPR/NMBR, BRS-3 should receive increased attention as possible approach for the development of novel treatments and/or diagnosis in lung-cancer.
Collapse
Affiliation(s)
- Paola Moreno
- Department of Health and Human Services, Digestive Diseases Branch, NIDDK, United States
| | - Samuel A Mantey
- Department of Health and Human Services, Digestive Diseases Branch, NIDDK, United States
| | - Suk H Lee
- Department of Health and Human Services, Digestive Diseases Branch, NIDDK, United States
| | - Irene Ramos-Álvarez
- Department of Health and Human Services, Digestive Diseases Branch, NIDDK, United States
| | - Terry W Moody
- Center for Cancer Research, Office of the Director, NCI, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Robert T Jensen
- Department of Health and Human Services, Digestive Diseases Branch, NIDDK, United States.
| |
Collapse
|
9
|
Clarimundo VS, Farinon M, Pedó RT, Teixeira VON, Nör C, Gulko PS, Xavier RM, de Oliveira PG. Gastrin-releasing peptide and its receptor increase arthritis fibroblast-like synoviocytes invasiveness through activating the PI3K/AKT pathway. Peptides 2017; 95:57-61. [PMID: 28733141 DOI: 10.1016/j.peptides.2017.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 06/28/2017] [Accepted: 07/13/2017] [Indexed: 10/19/2022]
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease that leads to joint destruction. The fibroblast-like synoviocytes (FLS) has a central role on the disease pathophysiology. The present study aimed to examine the role of gastrin-releasing peptide (GRP) and its receptor (GRPR) on invasive behavior of mice fibroblast-like synoviocytes (FLS), as well as to evaluate GRP-induced signaling on PI3K/AKT pathway. The expression of GRPR in FLS was investigated by immunocytochemistry, western blot (WB) and qRT-PCR. The proliferation and invasion were assessed by SRB and matrigel-transwell assay after treatment with GRP and/or RC-3095 (GRPR antagonist), and/or Ly294002 (inhibitor of PI3K/AKT pathway). Finally, AKT phosphorylation was assessed by WB. GRPR protein was detected in FLS and the exposure to GRP increased FLS invasion by nearly two-fold, compared with untreated cells (p<0.05), while RC-3095 reversed that effect (p<0.001). GRP also increased phosphorylated AKT expression in FLS. When Ly294002 was added with GRP, it prevented the GRP-induced increased cell invasiveness (p<0.001). These data suggest that GRPR expression in FLS and that exogenous GRP are able to activate FLS invasion. This effect occurs at least in part through the AKT activation. Therefore, understanding of the GRP/GRPR pathway could be relevant in the development of FLS-targeted therapy for RA.
Collapse
Affiliation(s)
- Vanessa Schuck Clarimundo
- Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil
| | - Mirian Farinon
- Departamento de Medicina, Universidade Federal do Rio Grande do Sul,Jerônimo de Ornellas Avenue, 721, 90040-001, Porto Alegre, RS, Brazil; Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil
| | - Renata Ternus Pedó
- Departamento de Medicina, Universidade Federal do Rio Grande do Sul,Jerônimo de Ornellas Avenue, 721, 90040-001, Porto Alegre, RS, Brazil; Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil
| | - Vivian Oliveira Nunes Teixeira
- Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil
| | - Carolina Nör
- Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Percio S Gulko
- Division of Rheumatology, Icahn School of Medicine at Mount Sinai, 10029 NY, United States
| | - Ricardo Machado Xavier
- Departamento de Medicina, Universidade Federal do Rio Grande do Sul,Jerônimo de Ornellas Avenue, 721, 90040-001, Porto Alegre, RS, Brazil; Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil.
| | - Patricia Gnieslaw de Oliveira
- Departamento de Medicina, Universidade Federal do Rio Grande do Sul,Jerônimo de Ornellas Avenue, 721, 90040-001, Porto Alegre, RS, Brazil; Laboratório de Doenças Autoimunes, Serviço de Reumatologia, Hospital de Clínicas de Porto Alegre, Ramiro Barcellos Sreet, 2350, Room 645, 90035-003, Porto Alegre, RS, Brazil
| |
Collapse
|
10
|
Hallasch S, Frick S, Jung M, Hilger I. How gastrin-releasing peptide receptor (GRPR) and α vβ 3 integrin expression reflect reorganization features of tumors after hyperthermia treatments. Sci Rep 2017; 7:6916. [PMID: 28761146 PMCID: PMC5537297 DOI: 10.1038/s41598-017-06100-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/07/2017] [Indexed: 12/19/2022] Open
Abstract
The outcome of tumor treatment via hyperthermia in the clinic has been reported to be heterogeneous. Here, we assessed how the presence of gastrin-releasing peptide receptor (GRPR) and αvβ3 integrin together with the morphology of the vascularization reflects the growth behavior of tumors after hyperthermia treatment. MDA-MB-231 tumor bearing mice were treated either with high (46 °C) or low dose (42 °C) water hyperthermia for 60 min. Changes of GRPR and αvβ3 integrin expression were assessed via multiplexed optical imaging. Vascularization was reconstructed and quantified by µCT imaging after contrast agent injection. We found that high dose hyperthermia is capable of increasing the expression of GRPR, αvβ3 integrin, CD31, and Ki67 in tumors. Also the morphology of tumor vasculature changed (increased relative blood volume and small-diameter vessel density, decreased expression of α-SMA). Low dose hyperthermia induced comparatively moderate effects on the investigated protein expression pattern and vascular remodeling. We conclude that under defined circumstances, specific temperature doses affect the reorganization of tumor regrowth, which is triggered by residual "dormant" cells even though tumor volumes are transiently decreasing. Further on, GRPR, αvβ3 integrin expression are versatile tools to surveil potential tumor regrow during therapy, beyond the conventional determination of tumor volumes.
Collapse
Affiliation(s)
- Sandra Hallasch
- Department of Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Am Klinikum 1, D-07747, Jena, Germany
| | - Sindy Frick
- Department of Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Am Klinikum 1, D-07747, Jena, Germany
| | - Maximilian Jung
- Department of Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Am Klinikum 1, D-07747, Jena, Germany
- Department of Medical Engineering and Biotechnology, University of Applied Science Jena, Carl-Zeiss Promenade 2, 07745, Jena, Germany
| | - Ingrid Hilger
- Department of Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Am Klinikum 1, D-07747, Jena, Germany.
| |
Collapse
|
11
|
Epigallocatechin gallate protects BEAS-2B cells from lipopolysaccharide-induced apoptosis through upregulation of gastrin-releasing peptide. Mol Cell Biochem 2017; 434:105-111. [DOI: 10.1007/s11010-017-3040-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/12/2017] [Indexed: 01/20/2023]
|
12
|
Jaeger N, Czepielewski RS, Bagatini M, Porto BN, Bonorino C. Neuropeptide gastrin-releasing peptide induces PI3K/reactive oxygen species-dependent migration in lung adenocarcinoma cells. Tumour Biol 2017; 39:1010428317694321. [PMID: 28351312 DOI: 10.1177/1010428317694321] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Nerve fibers and neurotransmitters have increasingly been shown to have a role in tumor progression. Gastrin-releasing peptide is a neuropeptide linked to tumor aggressiveness, acting as an autocrine tumor growth factor by binding to its receptor, gastrin-releasing peptide receptor, expressed by many tumors. Although neuropeptides have been previously linked to tumor cell proliferation, more recent studies have uncovered roles for neuropeptides in chemotaxis and metastasis. Understanding the precise roles of such peptides in cancer is crucial to optimizing targeted therapy design. We have previously described that gastrin-releasing peptide acts directly as a chemotactic factor for neutrophils, dependent on PI3K, ERK, and p38. In this study, we investigated roles for gastrin-releasing peptide in lung adenocarcinoma. We asked if gastrin-releasing peptide would act as a proliferative and/or chemotactic stimulus for gastrin-releasing peptide receptor-expressing tumor cells. In A549 cells, a non-small cell lung carcinoma line, the treatment with gastrin-releasing peptide leads to activation of AKT and ERK1/2, and production of reactive oxygen species. Gastrin-releasing peptide induced migration of A549 cells, dependent on gastrin-releasing peptide receptor and PI3K, but not ERK. However, no proliferation was observed in these cells in response to gastrin-releasing peptide, and gastrin-releasing peptide did not promote resistance to treatment with a chemotherapy drug. Our results suggest that, similar to what happens in neutrophils, gastrin-releasing peptide is a migratory, rather than a proliferative, stimulus, for non-small cell lung carcinoma cells, indicating a putative role for gastrin-releasing peptide and gastrin-releasing peptide receptor in metastasis.
Collapse
Affiliation(s)
- Natália Jaeger
- 1 Laboratório de Imunologia Celular e Molecular, Hospital São Lucas, Instituto de Pesquisas Biomédicas (IPB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.,2 Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Rafael Sanguinetti Czepielewski
- 1 Laboratório de Imunologia Celular e Molecular, Hospital São Lucas, Instituto de Pesquisas Biomédicas (IPB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.,2 Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Maira Bagatini
- 1 Laboratório de Imunologia Celular e Molecular, Hospital São Lucas, Instituto de Pesquisas Biomédicas (IPB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Bárbara N Porto
- 3 Laboratório de Imunologia Clínica e Experimental, Hospital São Lucas, Instituto de Pesquisas Biomédicas (IPB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Cristina Bonorino
- 1 Laboratório de Imunologia Celular e Molecular, Hospital São Lucas, Instituto de Pesquisas Biomédicas (IPB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.,2 Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| |
Collapse
|
13
|
Liu Y, An S, Ward R, Yang Y, Guo XX, Li W, Xu TR. G protein-coupled receptors as promising cancer targets. Cancer Lett 2016; 376:226-39. [PMID: 27000991 DOI: 10.1016/j.canlet.2016.03.031] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 02/07/2023]
Abstract
G protein-coupled receptors (GPCRs) regulate an array of fundamental biological processes, such as growth, metabolism and homeostasis. Specifically, GPCRs are involved in cancer initiation and progression. However, compared with the involvement of the epidermal growth factor receptor in cancer, that of GPCRs have been largely ignored. Recent findings have implicated many GPCRs in tumorigenesis, tumor progression, invasion and metastasis. Moreover, GPCRs contribute to the establishment and maintenance of a microenvironment which is permissive for tumor formation and growth, including effects upon surrounding blood vessels, signaling molecules and the extracellular matrix. Thus, GPCRs are considered to be among the most useful drug targets against many solid cancers. Development of selective ligands targeting GPCRs may provide novel and effective treatment strategies against cancer and some anticancer compounds are now in clinical trials. Here, we focus on tumor related GPCRs, such as G protein-coupled receptor 30, the lysophosphatidic acid receptor, angiotensin receptors 1 and 2, the sphingosine 1-phosphate receptors and gastrin releasing peptide receptor. We also summarize their tissue distributions, activation and roles in tumorigenesis and discuss the potential use of GPCR agonists and antagonists in cancer therapy.
Collapse
Affiliation(s)
- Ying Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Su An
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Richard Ward
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Yang Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Xiao-Xi Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Wei Li
- Kidney Cancer Research, Diagnosis and Translational Technology Center of Yunnan Province, Department of Urology, The People's Hospital of Yunnan Province, Kunming, Yunnan 650032, China.
| | - Tian-Rui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
| |
Collapse
|
14
|
Ramos-Álvarez I, Moreno P, Mantey SA, Nakamura T, Nuche-Berenguer B, Moody TW, Coy DH, Jensen RT. Insights into bombesin receptors and ligands: Highlighting recent advances. Peptides 2015; 72:128-44. [PMID: 25976083 PMCID: PMC4641779 DOI: 10.1016/j.peptides.2015.04.026] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022]
Abstract
This following article is written for Prof. Abba Kastin's Festschrift, to add to the tribute to his important role in the advancement of the role of peptides in physiological, as well as pathophysiological processes. There have been many advances during the 35 years of his prominent role in the Peptide field, not only as editor of the journal Peptides, but also as a scientific investigator and editor of two volumes of the Handbook of Biological Active Peptides [146,147]. Similar to the advances with many different peptides, during this 35 year period, there have been much progress made in the understanding of the pharmacology, cell biology and the role of (bombesin) Bn receptors and their ligands in various disease states, since the original isolation of bombesin from skin of the European frog Bombina bombina in 1970 [76]. This paper will briefly review some of these advances over the time period of Prof. Kastin 35 years in the peptide field concentrating on the advances since 2007 when many of the results from earlier studies were summarized [128,129]. It is appropriate to do this because there have been 280 articles published in Peptides during this time on bombesin-related peptides and it accounts for almost 5% of all publications. Furthermore, 22 Bn publications we have been involved in have been published in either Peptides [14,39,55,58,81,92,93,119,152,216,225,226,231,280,302,309,355,361,362] or in Prof. Kastin's Handbook of Biological Active Peptides [137,138,331].
Collapse
Affiliation(s)
- Irene Ramos-Álvarez
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Paola Moreno
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Samuel A Mantey
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Taichi Nakamura
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Bernardo Nuche-Berenguer
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Terry W Moody
- Center for Cancer Research, Office of the Director, NCI, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - David H Coy
- Peptide Research Laboratory, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, United States
| | - Robert T Jensen
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States.
| |
Collapse
|
15
|
González N, Moreno P, Jensen RT. Bombesin receptor subtype 3 as a potential target for obesity and diabetes. Expert Opin Ther Targets 2015; 19:1153-70. [PMID: 26066663 DOI: 10.1517/14728222.2015.1056154] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Diabetes mellitus and obesity are important health issues; increasing in prevalence, both in the USA and globally. There are only limited pharmacological treatments, and although bariatric surgery is effective, new effective pharmacologic treatments would be of great value. This review covers one area of increasing interest that could yield new novel treatments of obesity/diabetes mellitus. It involves recognition of the central role the G-protein-coupled receptor, bombesin receptor subtype 3 (BRS-3) plays in energy/glucose metabolism. AREAS COVERED Since the initial observation that BRS-3 knockout mice develop obesity, hypertension, impaired glucose metabolism and hyperphagia, there have been numerous studies of the mechanisms involved and the development of selective BRS-3 agonists/antagonists, which have marked effects on body weight, feeding and glucose/insulin homeostasis. In this review, each of these areas is briefly reviewed. EXPERT OPINION BRS-3 plays an important role in glucose/energy homeostasis. The development of potent, selective BRS-3 agonists demonstrates promise as a novel approach to treat obesity/diabetic states. One important question that needs to be addressed is whether BRS-3 agonists need to be centrally acting. This is particularly important in light of recent animal and human studies that report transient cardiovascular side effects with centrally acting oral BRS agonists.
Collapse
Affiliation(s)
- Nieves González
- The Autonomous University of Madrid, IIS-Jiménez Díaz Foundation, Renal, Vascular and Diabetes Research Laboratory, Spanish Biomedical Research Network in Diabetes and, Associated Metabolic Disorders (CIBERDEM) , Madrid , Spain
| | | | | |
Collapse
|
16
|
Jia Y, Shi H, Fan D. Significance of gastrin-releasing peptide in ovarian cancer ES2 cells. Oncol Lett 2015; 10:359-363. [PMID: 26171030 DOI: 10.3892/ol.2015.3240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 03/04/2015] [Indexed: 01/21/2023] Open
Abstract
The present study aimed to investigate the effect of gastrin-releasing peptide (GRP) on the proliferation and invasion of ovarian cancer ES2 cells. The ovarian cancer ES2 cells were transfected with small interfering RNA against GRP. Cell proliferation was assessed using the Trypan blue assay, apoptosis was determined using propidium iodide/fluorescein isothiocyanate and flow cytometry, and the invasion ability was detected using the Transwell assay. The results revealed that the expression of GRP significantly decreased following transfection with GRP-short hairpin RNA. Furthermore, the silencing of GRP resulted in increased apoptosis and a reduced invasive ability of the ES2 cells. It was concluded that GRP may regulate the proliferation and migration of human ovarian cancer cells, which indicates that GRP may be a potential novel target for the treatment of ovarian cancer.
Collapse
Affiliation(s)
- Yanyan Jia
- Department of Gynecology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Huirong Shi
- Department of Gynecology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Dongmei Fan
- Department of Gynecology, The First Affiliated Hospital, Henan Scientific and Technologic University, Luoyang, Henan 471003, P.R. China
| |
Collapse
|
17
|
Santos J, Mesquita D, Barros-Silva JD, Jerónimo C, Henrique R, Morais A, Paulo P, Teixeira MR. Uncovering potential downstream targets of oncogenic GRPR overexpression in prostate carcinomas harboring ETS rearrangements. Oncoscience 2015; 2:497-507. [PMID: 26097883 PMCID: PMC4468336 DOI: 10.18632/oncoscience.142] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/13/2015] [Indexed: 01/14/2023] Open
Abstract
Gastrin-releasing peptide receptor (GRPR) is known to be overexpressed in several human malignancies, including prostate cancer, and has been implicated in multiple important neoplastic signaling pathways. We recently have shown that GRPR is an ERG and ETV1 target gene in prostate cancer, using a genome-wide scale and exon-level expression microarray platform. Due to its cellular localization, the relevance of its function and the availability of blocking agents, GRPR seems to be a promising candidate as therapeutic target. Our present work shows that effective knockdown of GRPR in LNCaP and VCaP cells attenuates their malignant phenotype by decreasing proliferation, invasion and anchorage-independent growth, while increasing apoptosis. Using an antibody microarray we were able to validate known and identify new targets of GRPR pathway, namely AKT1, PKCε, TYK2 and MST1. Finally, we show that overexpression of these GRPR targets is restricted to prostate carcinomas harboring ERG and/or ETV1 rearrangements, establishing their potential as therapeutic targets for these particular molecular subsets of the disease.
Collapse
Affiliation(s)
- Joana Santos
- Department of Genetics and Cancer Genetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal
| | - Diana Mesquita
- Department of Genetics and Cancer Genetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal
| | - João D Barros-Silva
- Department of Genetics and Cancer Genetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal
| | - Carmen Jerónimo
- Cancer Biology and Epigenetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal ; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira, Porto, Portugal
| | - Rui Henrique
- Cancer Biology and Epigenetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal ; Department of Pathology, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal ; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira, Porto, Portugal
| | - António Morais
- Department of Urology, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal
| | - Paula Paulo
- Department of Genetics and Cancer Genetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal
| | - Manuel R Teixeira
- Department of Genetics and Cancer Genetics Group - CI-IPOP, Portuguese Oncology Institute-Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal ; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira, Porto, Portugal
| |
Collapse
|
18
|
Mattei J, Achcar RD, Cano CH, Macedo BR, Meurer L, Batlle BS, Groshong SD, Kulczynski JM, Roesler R, Dal Lago L, Brunetto AT, Schwartsmann G. Gastrin-Releasing Peptide Receptor Expression in Lung Cancer. Arch Pathol Lab Med 2014; 138:98-104. [DOI: 10.5858/arpa.2012-0679-oa] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
19
|
Di Florio A, Sancho V, Moreno P, Fave GD, Jensen RT. Gastrointestinal hormones stimulate growth of Foregut Neuroendocrine Tumors by transactivating the EGF receptor. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1833:573-82. [PMID: 23220008 PMCID: PMC3556220 DOI: 10.1016/j.bbamcr.2012.11.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 11/22/2012] [Accepted: 11/24/2012] [Indexed: 02/07/2023]
Abstract
Foregut neuroendocrine tumors [NETs] usually pursuit a benign course, but some show aggressive behavior. The treatment of patients with advanced NETs is marginally effective and new approaches are needed. In other tumors, transactivation of the EGF receptor (EGFR) by growth factors, gastrointestinal (GI) hormones and lipids can stimulate growth, which has led to new treatments. Recent studies show a direct correlation between NET malignancy and EGFR expression, EGFR inhibition decreases basal NET growth and an autocrine growth effect exerted by GI hormones, for some NETs. To determine if GI hormones can stimulate NET growth by inducing transactivation of EGFR, we examined the ability of EGF, TGFα and various GI hormones to stimulate growth of the human foregut carcinoid,BON, the somatostatinoma QGP-1 and the rat islet tumor,Rin-14B-cell lines. The EGFR tyrosine-kinase inhibitor, AG1478 strongly inhibited EGF and the GI hormones stimulated cell growth, both in BON and QGP-1 cells. In all the three neuroendocrine cell lines studied, we found EGF, TGFα and the other growth-stimulating GI hormones increased Tyr(1068) EGFR phosphorylation. In BON cells, both the GI hormones neurotensin and a bombesin analogue caused a time- and dose-dependent increase in EGFR phosphorylation, which was strongly inhibited by AG1478. Moreover, we found this stimulated phosphorylation was dependent on Src kinases, PKCs, matrix metalloproteinase activation and the generation of reactive oxygen species. These results raise the possibility that disruption of this signaling cascade by either EGFR inhibition alone or combined with receptor antagonists may be a novel therapeutic approach for treatment of foregut NETs/PETs.
Collapse
Affiliation(s)
- Alessia Di Florio
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Veronica Sancho
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Paola Moreno
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Gianfranco Delle Fave
- Digestive and Liver Disease Unit, II Medical School, University La Sapienza, S. Andrea Hospital, Via Di Grottarossa 00189, Rome, Italy
| | - Robert T. Jensen
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, USA
| |
Collapse
|
20
|
Rick FG, Buchholz S, Schally AV, Szalontay L, Krishan A, Datz C, Stadlmayr A, Aigner E, Perez R, Seitz S, Block NL, Hohla F. Combination of gastrin-releasing peptide antagonist with cytotoxic agents produces synergistic inhibition of growth of human experimental colon cancers. Cell Cycle 2012; 11:2518-25. [PMID: 22751419 DOI: 10.4161/cc.20900] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We investigated the efficacy of a powerful antagonist of bombesin/gastrin-releasing peptide (BN/GRP) RC-3940-II administered as a single agent or in combination with cytotoxic agents on the growth of HT-29, HCT-116 and HCT-15 human colon cancer in vitro and in vivo. GRP-receptor mRNA and protein were found in all three cell lines tested. Exposure of HT-29 cells to 10 μM RC-3940-II led to an increase in the number of cells blocked in S phase and G 2/M and cells with lower G(0)/G(1) DNA content. Similar changes on the cell cycle traverse of HT-29 cells could also be seen at lower concentrations of RC-3940-II (1 μM) after pretreatment with 100 nM GRP (14-27), indicating a dose-dependent mechanism of action based on the blockage of BN/GRP induced proliferation of tumor cells at lower concentrations. Daily in vivo treatment with BN/GRP antagonist RC-3940-II decreased the volume of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic nude mice by 25 to 67% (p < 0.005). Combined treatment with RC-3940-II and chemotherapeutic agents 5-FU and irinotecan resulted in a synergistic tumor growth suppression of HT-29, HCT-116 and HCT-15 xenografts by 43% to 78%. In HT-29 and HCT-116 xenografts the inhibition for the combinations of RC-3940-II and irinotecan vs. single substances (p < 0.05) was significantly greater. These findings support the use of RC-3940-II as an anticancer agent and may help to design clinical trials using RC-3940-II in combinations with cytotoxic agents.
Collapse
Affiliation(s)
- Ferenc G Rick
- Endocrine, Polypeptide and Cancer Institute, Veterans Affairs Medical Center, Miami, FL, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Egloff AM, Liu X, Davis ALG, Trevelline BK, Vuga M, Siegfried JM, Grandis JR. Elevated gastrin-releasing peptide receptor mRNA expression in buccal mucosa: association with head and neck squamous cell carcinoma. Head Neck 2012; 35:270-9. [PMID: 22431275 DOI: 10.1002/hed.22963] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2011] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Expression of gastrin-releasing peptide receptor (GRPR) is elevated in mucosa adjacent to head and neck squamous cell carcinoma (HNSCC) compared with mucosa from cancer-free controls, suggesting elevated GRPR expression may indicate presence of HNSCC. METHODS We measured GRPR mRNA levels in histologically normal buccal mucosa from 65 surgical patients with HNSCC and 75 cancer-free control subjects using quantitative polymerase chain reaction (PCR). We tested for association between GRPR expression and HNSCC and evaluated differences in patient progression-free survival (PFS). RESULTS Buccal GRPR expression was higher in cases but not controls who were active smokers (p = .04). High GRPR expression was associated with HNSCC (odds ratio [OR] = 3.55; 95% confidence interval [CI] = 1.15-10.93), even after adjustment for age, sex, tobacco use, and sample storage time. PFS did not differ between patients with HNSCC with high versus low GRPR expression (p = .22). CONCLUSION Elevated buccal GRPR expression was significantly associated with HNSCC independent of known risk factors but was not an indicator of disease prognosis.
Collapse
Affiliation(s)
- Ann Marie Egloff
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Egloff AM, Gaither Davis A, Shuai Y, Land S, Pilewski JM, Luketich JD, Landreneau R, Miller YE, Grandis JR, Siegfried JM. Gastrin-releasing peptide receptor expression in non-cancerous bronchial epithelia is associated with lung cancer: a case-control study. Respir Res 2012; 13:9. [PMID: 22296774 PMCID: PMC3305653 DOI: 10.1186/1465-9921-13-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 02/01/2012] [Indexed: 11/17/2022] Open
Abstract
Background Normal bronchial tissue expression of GRPR, which encodes the gastrin-releasing peptide receptor, has been previously reported by us to be associated with lung cancer risk in 78 subjects, especially in females. We sought to define the contribution of GRPR expression in bronchial epithelia to lung cancer risk in a larger case-control study where adjustments could be made for tobacco exposure and sex. Methods We evaluated GRPR mRNA levels in histologically normal bronchial epithelial cells from 224 lung cancer patients and 107 surgical cancer-free controls. Associations with lung cancer were tested using logistic regression models. Results Bronchial GRPR expression was significantly associated with lung cancer (OR = 4.76; 95% CI = 2.32-9.77) in a multivariable logistic regression (MLR) model adjusted for age, sex, smoking status and pulmonary function. MLR analysis stratified by smoking status indicated that ORs were higher in never and former smokers (OR = 7.74; 95% CI = 2.96-20.25) compared to active smokers (OR = 1.69; 95% CI = 0.46-6.33). GRPR expression did not differ by subject sex, and lung cancer risk associated with GRPR expression was not modified by sex. Conclusions GRPR expression in non-cancerous bronchial epithelium was significantly associated with the presence of lung cancer in never and former smokers. The association in never and former smokers was found in males and females. Association with lung cancer did not differ by sex in any smoking group.
Collapse
Affiliation(s)
- Ann Marie Egloff
- Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Roesler R, Schwartsmann G. Gastrin-releasing peptide receptors in the central nervous system: role in brain function and as a drug target. Front Endocrinol (Lausanne) 2012; 3:159. [PMID: 23251133 PMCID: PMC3523293 DOI: 10.3389/fendo.2012.00159] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 11/23/2012] [Indexed: 11/13/2022] Open
Abstract
Neuropeptides acting on specific cell membrane receptors of the G protein-coupled receptor (GPCR) superfamily regulate a range of important aspects of nervous and neuroendocrine function. Gastrin-releasing peptide (GRP) is a mammalian neuropeptide that binds to the GRP receptor (GRPR, BB2). Increasing evidence indicates that GRPR-mediated signaling in the central nervous system (CNS) plays an important role in regulating brain function, including aspects related to emotional responses, social interaction, memory, and feeding behavior. In addition, some alterations in GRP or GRPR expression or function have been described in patients with neurodegenerative, neurodevelopmental, and psychiatric disorders, as well as in brain tumors. Findings from preclinical models are consistent with the view that the GRPR might play a role in brain disorders, and raise the possibility that GRPR agonists might ameliorate cognitive and social deficits associated with neurological diseases, while antagonists may reduce anxiety and inhibit the growth of some types of brain cancer. Further preclinical and translational studies evaluating the potential therapeutic effects of GRPR ligands are warranted.
Collapse
Affiliation(s)
- Rafael Roesler
- Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do SulPorto Alegre, Brazil
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do SulPorto Alegre, Brazil
- National Institute for Translational MedicinePorto Alegre, Brazil
- *Correspondence: Rafael Roesler, Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, Rio Grande do Sul, Brazil. e-mail:
| | - Gilberto Schwartsmann
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do SulPorto Alegre, Brazil
- National Institute for Translational MedicinePorto Alegre, Brazil
- Department of Internal Medicine, School of Medicine, Federal University of Rio Grande do SulPorto Alegre, Brazil
| |
Collapse
|
24
|
Moody TW, Sancho V, di Florio A, Nuche-Berenguer B, Mantey S, Jensen RT. Bombesin receptor subtype-3 agonists stimulate the growth of lung cancer cells and increase EGF receptor tyrosine phosphorylation. Peptides 2011; 32:1677-84. [PMID: 21712056 PMCID: PMC3152616 DOI: 10.1016/j.peptides.2011.06.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 06/13/2011] [Accepted: 06/13/2011] [Indexed: 10/18/2022]
Abstract
The effects of bombesin receptor subtype-3 (BRS-3) agonists were investigated on lung cancer cells. The BRS-3 agonist (DTyr(6), (Ala(11), Phe(13), Nle(14)) bombesin(6-14) (BA1), but not gastrin releasing peptide (GRP) or neuromedin B (NMB) increased significantly the clonal growth of NCI-H1299 cells stably transfected with BRS-3 (NCI-H1299-BRS-3). Also, BA1 addition to NCI-H727 or NCI-H1299-BRS-3 cells caused Tyr(1068) phosphorylation of the epidermal growth factor receptor (EGFR). Similarly, (DTyr(6), R-Apa(11), Phe(13), Nle(14)) bombesin(6-14) (BA2) and (DTyr(6), R-Apa(11), 4-Cl,Phe(13), Nle(14)) bombesin(6-14) (BA3) but not gastrin releasing peptide (GRP) or neuromedin B (NMB) caused EGFR transactivation in NCI-H1299-BRS-3 cells. BA1-induced EGFR or ERK tyrosine phosphorylation was not inhibited by addition of BW2258U89 (BB(2)R antagonist) or PD168368 (BB(1)R antagonist) but was blocked by (DNal-Cys-Tyr-DTrp-Lys-Val-Cys-Nal)NH(2) (BRS-3 ant.). The BRS-3 ant. reduced clonal growth of NCI-H1299-BRS-3 cells. BA1, BA2, BA3 and BRS-3 ant. inhibit specific (125)I-BA1 binding to NCI-H1299-BRS-3 cells with an IC(50) values of 1.1, 21, 15 and 750nM, respectively. The ability of BRS-3 to regulate EGFR transactivation in NCI-H1299-BRS-3 cells was reduced by AG1478 or gefitinib (EGFR tyrosine kinase inhibitors), GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor), N-acetylcysteine (anti-oxidant), Tiron (superoxide scavenger) and DPI (NADPH oxidase inhibitor). These results demonstrate that BRS-3 agonists may stimulate lung cancer growth as a result of EGFR transactivation and that the transactivation is regulated by BRS-3 in a Src-, reactive oxygen and matrix metalloprotease-dependent manner.
Collapse
Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of Director, Bethesda, MD 20892, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Strauss LG, Koczan D, Seiz M, Tuettenberg J, Schmieder K, Pan L, Cheng C, Dimitrakopoulou-Strauss A. Correlation of the Ga-68-Bombesin Analog Ga-68-BZH3 with Receptors Expression in Gliomas as Measured by Quantitative Dynamic Positron Emission Tomography (dPET) and Gene Arrays. Mol Imaging Biol 2011; 14:376-83. [DOI: 10.1007/s11307-011-0508-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
26
|
Brunetto de Farias C, Rosemberg DB, Heinen TE, Koehler-Santos P, Abujamra AL, Kapczinski F, Brunetto AL, Ashton-Prolla P, Meurer L, Reis Bogo M, Damin DC, Schwartsmann G, Roesler R. BDNF/TrkB content and interaction with gastrin-releasing peptide receptor blockade in colorectal cancer. Oncology 2011; 79:430-9. [PMID: 21474968 DOI: 10.1159/000326564] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 01/04/2011] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Neurotrophin and neuropeptide pathways are emerging targets in cancer. Here we show that brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, are present in colorectal cancer and that BDNF levels are increased in tumors compared to nontumor tissue. In addition, we investigate the role of BDNF in influencing the response of colorectal cancer cells to inhibition of gastrin-releasing peptide receptors (GRPR). METHODS Fresh-frozen sporadic colorectal adenocarcinoma specimens and adjacent nonneoplastic tissue from 30 patients, as well as paraffin-embedded colorectal cancer samples from 21 patients, were used in this study. Cell proliferation and mRNA and protein levels were examined in HT-29 or SW620 cells treated with a GRPR antagonist, human recombinant BDNF (hrBDNF), a Trk antagonist K252a, or cetuximab. RESULTS Expression of BDNF and TrkB was detected in tumor samples and cell lines. BDNF levels were higher in tumor samples compared to nonneoplastic tissue. BDNF expression and secretion were increased by GRPR blockade in HT-29 cells through a mechanism dependent on epidermal growth factor receptors. Treatment with hrBDNF prevented the effect of GRPR blockade on cell proliferation, whereas a Trk inhibitor reduced proliferation. CONCLUSIONS BDNF and TrkB are present in colorectal cancer and might contribute to resistance to GRPR antagonists.
Collapse
|
27
|
Dulak AM, Gubish CT, Stabile LP, Henry C, Siegfried JM. HGF-independent potentiation of EGFR action by c-Met. Oncogene 2011; 30:3625-35. [PMID: 21423210 PMCID: PMC3126872 DOI: 10.1038/onc.2011.84] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The c-Met receptor is a potential therapeutic target for non-small cell lung cancer (NSCLC). Signaling interactions between c-Met and the mutant Epidermal Growth Factor Receptor (EGFR) have been studied extensively, but signaling intermediates and biological consequences of lateral signaling to c-Met in EGFR wild-type tumors is minimally understood. Our observations indicate that delayed c-Met activation in NSCLC cell lines is initiated by wild-type EGFR, the receptor most often found in NSCLC tumors. EGFR ligands induce accumulation of activated c-Met which begins at 8 h continues for 48 h. This effect is accompanied by an increase in c-Met expression and phosphorylation of critical c-Met tyrosine residues without activation of MAPK or Akt. Gene transcription is required for delayed c-Met activation; however, phosphorylation of c-Met by EGFR occurs without production of HGF or another secreted factor, supporting a ligand-independent mechanism. Lateral signaling is blocked by two selective c-Met tyrosine kinase inhibitors (TKIs), PF2341066 and SU11274, or with gefitinib, an EGFR TKI, suggesting kinase activity of both receptors is required for this effect. Prolonged c-Src phosphorylation is observed, and c-Src pathway is essential for EGFR to c-Met communication. Pre-treatment with pan-SFK inhibitors, PP2 and dasatinib, abolishes delayed c-Met phosphorylation. A c-Src dominant-negative construct reduces EGF-induced c-Met phosphorylation compared to control, further, confirming a c-Src requirement. Inhibition of c-Met with PF2341066 and siRNA decreases EGF-induced phenotypes of invasion by ~86% and motility by ~81%, suggesting that a novel form of c-Met activation is utilized by EGFR to maximize these biological effects. Combined targeting of c-Met and EGFR leads to increased xenograft anti-tumor activity, demonstrating that inhibition of downstream and lateral signaling from the EGFR-c-Src-c-Met axis might be effective in treatment of NSCLC.
Collapse
Affiliation(s)
- A M Dulak
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | | | | |
Collapse
|
28
|
Ligands of Epidermal Growth Factor Receptor and the Insulin-Like Growth Factor Family as Serum Biomarkers for Response to Epidermal Growth Factor Receptor Inhibitors in Patients with Advanced Non-small Cell Lung Cancer. J Thorac Oncol 2010; 5:1939-48. [DOI: 10.1097/jto.0b013e3181f77a39] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
29
|
Ferris RL, Jaffee EM, Ferrone S. Tumor antigen-targeted, monoclonal antibody-based immunotherapy: clinical response, cellular immunity, and immunoescape. J Clin Oncol 2010; 28:4390-9. [PMID: 20697078 PMCID: PMC2954137 DOI: 10.1200/jco.2009.27.6360] [Citation(s) in RCA: 239] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 06/21/2010] [Indexed: 12/28/2022] Open
Abstract
PURPOSE Tumor antigen (TA) -targeted monoclonal antibodies (mAb), rituximab, trastuzumab, and cetuximab, are clinically effective for some advanced malignancies, especially in conjunction with chemotherapy and/or radiotherapy. However, these results are only seen in a subset (20% to 30%) of patients. We discuss the immunologic mechanism(s) underlying these clinical findings and their potential role in the variability in patients' clinical response. METHODS We reviewed the evidence indicating that the effects of TA-targeted mAb-based immunotherapy are mediated not only by inhibition of signaling pathways, but also by cell-mediated cytotoxicity triggered by the infused TA-targeted mAb. We analyzed the immunologic variables that can influence the outcome of antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro and in animal model systems. We also analyzed the correlation reported between these variables and the clinical response to mAb-based immunotherapy. RESULTS Of the variables that influence ADCC mediated by TA-targeted mAb, only polymorphisms of Fcγ receptors (FcγR) expressed by patients' lymphocytes were correlated with clinical efficacy. However, this correlation is not absolute and is not observed in all malignancies. Thus other variables may be responsible for the antitumor effects seen in mAb-treated patients. We discuss the evidence that triggering of TA-specific cellular immunity by TA-targeted mAb, in conjunction with immune escape mechanisms used by tumor cells, may contribute to the differential clinical responses to mAb-based immunotherapy. CONCLUSION Identification of the mechanism(s) underlying the clinical response of patients with cancer treated with TA-targeted mAb is crucial to optimizing their application in the clinic and to selecting the patients most likely to benefit from their use.
Collapse
Affiliation(s)
- Robert L Ferris
- The Hillman Cancer Center Research Pavilion, 5117 Centre Ave, Room 2.26b, Pittsburgh, PA 15213, USA.
| | | | | |
Collapse
|
30
|
Moody TW, Berna MJ, Mantey S, Sancho V, Ridnour L, Wink DA, Chan D, Giaccone G, Jensen RT. Neuromedin B receptors regulate EGF receptor tyrosine phosphorylation in lung cancer cells. Eur J Pharmacol 2010; 637:38-45. [PMID: 20388507 PMCID: PMC3921891 DOI: 10.1016/j.ejphar.2010.03.057] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 03/15/2010] [Accepted: 03/29/2010] [Indexed: 10/19/2022]
Abstract
Neuromedin B (NMB), a member of the bombesin family of peptides, is an autocrine growth factor for many lung cancer cells. The present study investigated the ability of NMB to cause transactivation of the epidermal growth factor (EGF) receptor in lung cancer cells. By Western blot, addition of NMB or related peptides to NCI-H1299 human non-small cell lung cancer (NSCLC) cells, caused phosphorylation of Tyr(1068) of the EGF receptor. The signal was amplified using NCI-H1299 cells stably transected with NMB receptors. The transactivation of the EGF receptor or the tyrosine phosphorylation of ERK caused by NMB-like peptides was inhibited by AG1478 or gefitinib (tyrosine kinase inhibitors) and NMB receptor antagonist PD168368 but not the GRP receptor antagonist, BW2258U89. The transactivation of the EGF receptor caused by NMB-like peptides was inhibited by GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor), or transforming growth factor (TGF)alpha antibody. The transactivation of the EGF receptor and the increase in reactive oxygen species caused by NMB-like peptides was inhibited by N-acetylcysteine (NAC) or Tiron. Gefitinib inhibited the proliferation of NCI-H1299 cells and its sensitivity was increased by the addition of PD168368. The results indicate that the NMB receptor regulates EGF receptor transactivation by a mechanism dependent on Src as well as metalloprotease activation and generation of reactive oxygen species.
Collapse
Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of the Director, Bethesda, Maryland 20892, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Li X, Lv Y, Yuan A, Li Z. Gastrin-releasing peptide links stressor to cancer progression. J Cancer Res Clin Oncol 2010; 136:483-91. [PMID: 20140628 DOI: 10.1007/s00432-010-0766-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 01/13/2010] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Gastrin-releasing peptide (GRP) plays an important role in cancer growth and metastasis; however, the mechanisms of how GRP affects cancer progression are not well understood. Recent studies revealed that chronic stress is a major risk factor for cancer progression, and this effect may be mediated by GRP. In this review, we will discuss the mechanisms and implications of GRP linking stressor to cancer progression. MATERIALS AND METHODS We retrieved the studies of the relationship between GRP, stress and cancers through PubMed using systematic methods to search, select, and evaluate the findings. RESULTS The results suggested that GRP can mediate the effects of stress on cancers at systemic, tissue and cellular levels: Stress elicits the secretion of GRP in the brain and GRP in turn activates the stress response pathways resulting in an elevation of stress hormones and GRP in the plasma and tissues. GRP in synergy with stress hormones stimulates the growth and invasion of cancer cells by suppressing the anti-tumor immune function and directly activating the pro-proliferative and pro-migratory signaling pathways in cancer cells. CONCLUSION GRP is a multi-functional peptide, which acts as a stress mediator as well as a growth factor linking stressor to cancer progression. GRP and its high-affinity receptor are useful targets for the diagnosis and treatment of cancers.
Collapse
Affiliation(s)
- Xinqiu Li
- Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, 277, West Yanta Road, 710061, Xi'an, People's Republic of China
| | | | | | | |
Collapse
|
32
|
Tu Z, Volk M, Shah K, Clerkin K, Liang JF. Constructing bioactive peptides with pH-dependent activities. Peptides 2009; 30:1523-8. [PMID: 19464332 PMCID: PMC2735074 DOI: 10.1016/j.peptides.2009.05.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 05/06/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
Abstract
Many bioactive peptides are featured by their arginine and lysine rich contents. In this study, lysine and arginine residues in lytic peptides were selectively replaced by histidines. Although resulting histidine-containing lytic peptides had decreased activity, they did show pH-dependent cytotoxicity. The activity of the constructed histidine-containing lytic peptides increased 2-8 times as the solution pH changed from 7.4 to 5.5. More importantly, these histidine-containing peptides maintain the same cell killing mechanism as their parent peptides by causing cell lysis. Both the activity and pH-sensitivity of histidine-containing peptides are tunable by adjusting histidine substitution numbers and positions. This study has presented a general strategy to create bioactive peptides with desired pH-sensitivity to meet the needs of various applications such as cancer treatments.
Collapse
Affiliation(s)
| | | | | | | | - Jun F. Liang
- Corresponding Author Dr. Jun F. Liang, Department of Chemistry, Chemical Biology, and Biomedical Engineering Stevens Institute of Technology Hoboken, NJ 07030 USA Tel.: 201-216-5640; Fax: 201-216-8240 Email.:
| |
Collapse
|
33
|
Kuroda K, Horiguchi A, Sumitomo M, Asano T, Ito K, Hayakawa M, Asano T. Activated Akt Prevents Antitumor Activity of Gefitinib in Renal Cancer Cells. Urology 2009; 74:209-15. [DOI: 10.1016/j.urology.2008.12.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 12/03/2008] [Accepted: 12/24/2008] [Indexed: 12/20/2022]
|
34
|
Roesler R, Valvassori SS, Castro AA, Luft T, Schwartsmann G, Quevedo J. Phosphoinositide 3-kinase is required for bombesin-induced enhancement of fear memory consolidation in the hippocampus. Peptides 2009; 30:1192-6. [PMID: 19463755 DOI: 10.1016/j.peptides.2009.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 02/08/2009] [Accepted: 02/11/2009] [Indexed: 11/21/2022]
Abstract
Increasing evidence indicates that the neuronal gastrin-releasing peptide-preferring bombesin receptor (GRPR) is a key molecular regulator of fear memory formation. However, the downstream signaling events remain poorly understood. The protooncogene product phosphoinositide 3-kinase (PI3K) has been implicated in regulating memory formation, as well as in mediating cellular responses to GRPR activation in glioma and neuroblastoma cells. We show here that GRPR modulation of fear memory consolidation in the rat hippocampus requires PI3K activation. Male Wistar rats received bilateral infusions of the GRPR agonist bombesin (BB) or the PI3K inhibitor LY294002 into the CA1 region of the dorsal hippocampus immediately after inhibitory avoidance (IA) conditioning. BB enhanced, whereas LY294002 impaired, IA memory retention. The BB-induced memory enhancement was blocked by coinfusion of either a GRPR antagonist or LY294002. These findings provide the first evidence suggesting that PI3K signaling is required for GRPR regulation of CNS function.
Collapse
Affiliation(s)
- Rafael Roesler
- Department of Pharmacology, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | | | | | | | | | | |
Collapse
|
35
|
Berna MJ, Tapia JA, Sancho V, Thill M, Pace A, Hoffmann KM, Gonzalez-Fernandez L, Jensen RT. Gastrointestinal growth factors and hormones have divergent effects on Akt activation. Cell Signal 2009; 21:622-38. [PMID: 19166928 PMCID: PMC2677382 DOI: 10.1016/j.cellsig.2009.01.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 12/16/2008] [Accepted: 01/02/2009] [Indexed: 12/11/2022]
Abstract
Akt is a central regulator of apoptosis, cell growth and survival. Growth factors and some G-protein-coupled receptors (GPCR) regulate Akt. Whereas growth-factor activation of Akt has been extensively studied, the regulation of Akt by GPCR's, especially gastrointestinal hormones/neurotransmitters, remains unclear. To address this area, in this study the effects of GI growth factors and hormones/neurotransmitters were investigated in rat pancreatic acinar cells which are high responsive to these agents. Pancreatic acini expressed Akt and 5 of 7 known pancreatic growth-factors stimulate Akt phosphorylation (T308, S473) and translocation. These effects are mediated by p85 phosphorylation and activation of PI3K. GI hormones increasing intracellular cAMP had similar effects. However, GI-hormones/neurotransmitters [CCK, bombesin, carbachol] activating phospholipase C (PLC) inhibited basal and growth-factor-stimulated Akt activation. Detailed studies with CCK, which has both physiological and pathophysiological effects on pancreatic acinar cells at different concentrations, demonstrated CCK has a biphasic effect: at low concentrations (pM) stimulating Akt by a Src-dependent mechanism and at higher concentrations (nM) inhibited basal and stimulated Akt translocation, phosphorylation and activation, by de-phosphorylating p85 resulting in decreasing PI3K activity. This effect required activation of both limbs of the PLC-pathway and a protein tyrosine phosphatase, but was not mediated by p44/42 MAPK, Src or activation of a serine phosphatase. Akt inhibition by CCK was also found in vivo and in Panc-1 cancer cells where it inhibited serum-mediated rescue from apoptosis. These results demonstrate that GI growth factors as well as gastrointestinal hormones/neurotransmitters with different cellular basis of action can all regulate Akt phosphorylation in pancreatic acinar cells. This regulation is complex with phospholipase C agents such as CCK, because both stimulatory and inhibitory effects can be seen, which are mediated by different mechanisms.
Collapse
Affiliation(s)
- Marc J. Berna
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
- Universitätsklinikum Eppendorf, Medizinische Klinik I, 20246 Hamburg, Germany
| | - Jose A. Tapia
- Departamento de Fisiologia, Universidad de Extremadura, Cáceres 10071, Spain
| | - Veronica Sancho
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| | - Michelle Thill
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892
- Universitätsklinikum Eppendorf, Klinik und Poliklinik für Augenheilkunde, 20246 Hamburg, Germany
| | - Andrea Pace
- Universitätsklinikum Eppendorf, Medizinische Klinik I, 20246 Hamburg, Germany
| | - K. Martin Hoffmann
- Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Auenbruggerplatz 30, A-8036 Graz, Austria
| | | | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1804, USA
| |
Collapse
|
36
|
Abstract
PURPOSE OF REVIEW This review will highlight recent advances in the understanding of molecular mechanisms by which mammalian bombesin receptors are regulated and which intracellular signaling pathways have been characterized to mediate agonist-dependent receptor biological effects. RECENT FINDINGS Mammalian bombesin receptors have been demonstrated to be involved in a larger array of physiological and pathophysiological conditions than previously reported. Pharmacological experiments in vitro and in vivo as well as utilization of animals genetically deficient of the gastrin-releasing peptide receptor demonstrated roles in memory and fear behavior, lung development and injury, small intestinal cell repair, autocrine tumor growth, and mediating signals for pruritus and penile reflexes. Intracellular signaling studies predominantly of the gastrin-releasing peptide receptor owing to its frequent overexpression in some human malignancies showed that PI3 kinase activation is an important mechanism of cell proliferation. Tumor cell treatment including gastrin-releasing peptide receptor antagonists combined with inhibition of epidermal growth factor receptor resulted in an additive effect on blocking cell proliferation. Novel molecular mechanisms of the orphan bombesin receptor subtype-3 and gastrin-releasing peptide receptor gene regulation have been elucidated. SUMMARY Inhibition of gastrin-releasing peptide receptor signaling in human malignancies represents an attractive target for pharmacological treatment. Novel functions of bombesin related peptides have been identified including processes in the central nervous system, lung and intestinal tract.
Collapse
Affiliation(s)
- H Christian Weber
- Boston University School of Medicine, Section of Gastroenterology, Boston, MA 02118, USA.
| |
Collapse
|
37
|
Yonesaka K, Zejnullahu K, Lindeman N, Homes AJ, Jackman DM, Zhao F, Rogers AM, Johnson BE, Jänne PA. Autocrine production of amphiregulin predicts sensitivity to both gefitinib and cetuximab in EGFR wild-type cancers. Clin Cancer Res 2008; 14:6963-73. [PMID: 18980991 DOI: 10.1158/1078-0432.ccr-08-0957] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, gefitinib and erlotinib, lead to significant tumor regressions in 10% to 15% of non-small cell lung cancer (NSCLC) patients with EGFR activating mutations. However, 30% to 40% of NSCLC patients, majority of whom are EGFR wild-type, develop stable disease following EGFR tyrosine kinase inhibitor therapy. EGFR-directed antibodies (cetuximab) are effective treatments for head and neck squamous cell carcinomas, which seldom contain EGFR mutations. The determinant(s) of efficacy of EGFR-targeted therapies in EGFR wild-type cancers is not well defined. EXPERIMENTAL DESIGN We examined the relationship of EGFR ligands, EGF, transforming growth factor-alpha,and amphiregulin and the efficacy of gefitinib and cetuximab in EGFR wild-type NSCLC (n=10) and head and neck squamous cell carcinoma (n=4) cell lines. We compared amphiregulin expression using immunohistochemistry in EGFR wild-type NSCLC patients (n=24) that developed either stable or progressive disease following erlotinib or gefitinib treatment. RESULTS Cell lines which produced >or=20 pmol/L amphiregulin, as detected by an ELISA, were significantly more likely to be growth inhibited by both gefitinib and cetuximab than those that produced minimal or no amphiregulin. In these cell lines, both cetuximab and gefitinib led to cell cycle arrest at the G(1)-S boundary and was associated with preferential inhibition of extracellular signal-regulated kinase 1/2 but not Akt signaling. Amphiregulin expression was significantly higher in NSCLC patients that developed stable disease compared with those that developed disease progression following gefitinib or erlotinib treatment. CONCLUSIONS Amphiregulin expression may help select EGFR wild-type patients who are likely to develop stable disease from EGFR-targeted therapies.
Collapse
Affiliation(s)
- Kimio Yonesaka
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
VanMeter AJ, Rodriguez AS, Bowman ED, Jen J, Harris CC, Deng J, Calvert VS, Silvestri A, Fredolini C, Chandhoke V, Petricoin EF, Liotta LA, Espina V. Laser capture microdissection and protein microarray analysis of human non-small cell lung cancer: differential epidermal growth factor receptor (EGPR) phosphorylation events associated with mutated EGFR compared with wild type. Mol Cell Proteomics 2008; 7:1902-24. [PMID: 18687633 DOI: 10.1074/mcp.m800204-mcp200] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Little is known about lung carcinoma epidermal growth factor (EGF) kinase pathway signaling within the context of the tissue microenvironment. We quantitatively profiled the phosphorylation and abundance of signal pathway proteins relevant to the EGF receptor within laser capture microdissected untreated, human non-small cell lung cancer (NSCLC) (n = 25) of known epidermal growth factor receptor (EGFR) tyrosine kinase domain mutation status. We measured six phosphorylation sites on EGFR to evaluate whether EGFR mutation status in vivo was associated with the coordinated phosphorylation of specific multiple phosphorylation sites on the EGFR and downstream proteins. Reverse phase protein array quantitation of NSCLC revealed simultaneous increased phosphorylation of EGFR residues Tyr-1148 (p < 0.044) and Tyr-1068 (p < 0.026) and decreased phosphorylation of EGFR Tyr-1045 (p < 0.002), HER2 Tyr-1248 (p < 0.015), IRS-1 Ser-612 (p < 0.001), and SMAD Ser-465/467 (p < 0.011) across all classes of mutated EGFR patient samples compared with wild type. To explore which subset of correlations was influenced by ligand induction versus an intrinsic phenotype of the EGFR mutants, we profiled the time course of 115 cellular signal proteins for EGF ligand-stimulated (three dosages) NSCLC mutant and wild type cultured cell lines. EGFR mutant cell lines (H1975 L858R) displayed a pattern of EGFR Tyr-1045 and HER2 Tyr-1248 phosphorylation similar to that found in tissue. Persistence of phosphorylation for AKT Ser-473 following ligand stimulation was found for the mutant. These data suggest that a higher proportion of the EGFR mutant carcinoma cells may exhibit activation of the phosphatidylinositol 3-kinase/protein kinase B (AKT)/mammalian target of rapamycin (MTOR) pathway through Tyr-1148 and Tyr-1068 and suppression of IRS-1 Ser-612, altered heterodimerization with ERBB2, reduced response to transforming growth factor beta suppression, and reduced ubiquitination/degradation of the EGFR through EGFR Tyr-1045, thus providing a survival advantage. This is the first comparison of multiple, site-specific phosphoproteins with the EGFR tyrosine kinase domain mutation status in vivo.
Collapse
Affiliation(s)
- Amy J VanMeter
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Baroni A, Perfetto B, Canozo N, Braca A, Farina E, Melito A, De Maria S, Cartenì M. Bombesin: a possible role in wound repair. Peptides 2008; 29:1157-66. [PMID: 18455266 DOI: 10.1016/j.peptides.2008.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 03/03/2008] [Accepted: 03/05/2008] [Indexed: 12/31/2022]
Abstract
During tissue regeneration and wound healing of the skin, migration, proliferation and differentiation of keratinocytes are important processes. Here we assessed the effect of a neuropeptide, bombesin, on keratinocytes during regeneration from scratch wounding. Bombesin purified from amphibian skin, is homologous of mammalian gastrin-releasing peptide and is active in mammals. Its pharmacological effects mediate various physiological activities: hypertensive action, stimulating action on gastric secretion, hyperglycemic effect or increased insulin secretion. In vitro it shows a hyperproliferative effect on different experimental models and is involved in skin repair. The aim of this study was to elucidate the effect of Bombesin in an in vitro experimental model on a mechanically injured human keratinocyte monolayer. We evaluated different mediators involved in wound repair such as IL-8, TGFbeta, IL-1, COX-2, VEGF and Toll-like receptors 2 and 4 (TLR2 and TLR4). We also studied the effects of bombesin on cell proliferation and motility and its direct effect on wound repair by observing the wound closure after mechanical injury. The involvement of the bombesin receptors neuromedin receptor (NMBR) and gastrin-releasing peptide receptor (GRP-R) was also evaluated. Our data suggest that bombesin may have an important role in skin repair by regulating the expression of healing markers. It enhanced the expression of IL-8, TGFbeta, COX-2 and VEGF. It also enhanced the expression of TLR2, while TLR4 was not expressed. Bombesin also increased cell growth and migration. In addition, we showed that NMBR was more involved in our experimental model compared to GRP-R.
Collapse
Affiliation(s)
- A Baroni
- Department of Dermatology, Faculty of Medicine and Surgery, Second University of Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Jensen RT, Battey JF, Spindel ER, Benya RV. International Union of Pharmacology. LXVIII. Mammalian bombesin receptors: nomenclature, distribution, pharmacology, signaling, and functions in normal and disease states. Pharmacol Rev 2008; 60:1-42. [PMID: 18055507 PMCID: PMC2517428 DOI: 10.1124/pr.107.07108] [Citation(s) in RCA: 395] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mammalian bombesin receptor family comprises three G protein-coupled heptahelical receptors: the neuromedin B (NMB) receptor (BB(1)), the gastrin-releasing peptide (GRP) receptor (BB(2)), and the orphan receptor bombesin receptor subtype 3 (BRS-3) (BB(3)). Each receptor is widely distributed, especially in the gastrointestinal (GI) tract and central nervous system (CNS), and the receptors have a large range of effects in both normal physiology and pathophysiological conditions. The mammalian bombesin peptides, GRP and NMB, demonstrate a broad spectrum of pharmacological/biological responses. GRP stimulates smooth muscle contraction and GI motility, release of numerous GI hormones/neurotransmitters, and secretion and/or hormone release from the pancreas, stomach, colon, and numerous endocrine organs and has potent effects on immune cells, potent growth effects on both normal tissues and tumors, potent CNS effects, including regulation of circadian rhythm, thermoregulation; anxiety/fear responses, food intake, and numerous CNS effects on the GI tract as well as the spinal transmission of chronic pruritus. NMB causes contraction of smooth muscle, has growth effects in various tissues, has CNS effects, including effects on feeding and thermoregulation, regulates thyroid-stimulating hormone release, stimulates various CNS neurons, has behavioral effects, and has effects on spinal sensory transmission. GRP, and to a lesser extent NMB, affects growth and/or differentiation of various human tumors, including colon, prostate, lung, and some gynecologic cancers. Knockout studies show that BB(3) has important effects in energy balance, glucose homeostasis, control of body weight, lung development and response to injury, tumor growth, and perhaps GI motility. This review summarizes advances in our understanding of the biology/pharmacology of these receptors, including their classification, structure, pharmacology, physiology, and role in pathophysiological conditions.
Collapse
Affiliation(s)
- R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
| | | | | | | |
Collapse
|
41
|
Gonzalez N, Moody TW, Igarashi H, Ito T, Jensen RT. Bombesin-related peptides and their receptors: recent advances in their role in physiology and disease states. Curr Opin Endocrinol Diabetes Obes 2008; 15:58-64. [PMID: 18185064 PMCID: PMC2631407 DOI: 10.1097/med.0b013e3282f3709b] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Mammalian bombesin-related peptides, gastrin-releasing peptide and neuromedin B actions are mediated by two receptors (BB1-receptor, BB2-receptor), which are closely related to the orphan receptor BRS-3 (BB3-receptor). The purpose of this review is to highlight advances in the understanding of these peptides in physiology/disease states. RECENT FINDINGS Pharmacologic/receptor-knockout studies show involvement of these receptors in a number of new processes/diseases. Neuromedin B/BB1-receptor is an important physiological regulator of pituitary-thyroid function; in mediating behavior, especially feas/anxiety; in mediating satiety through different cascades than gastrin-releasing peptide/BB2 receptors and for its autocrine tumor-growth effects. Gastrin-releasing peptide/BB2-receptor plays important roles in mediating signals for pruritus, lung development/injury, small intestinal mucosal defense, and central nervous system processes such as learning/memory. The signaling mechanisms of its potent growth effects are being elucidated and their possible therapeutic targets identified. BB3-receptor knockout mice provided insights for their obesity/glucose intolerance and demonstrated that this receptor may be important in the lung response to injury, tumor growth and gastrointestinal motility. Each receptor is frequently overexpressed in human tumors and has potent growth effects. This effect is being explored to develop new antitumor treatments, such as bombesin-receptor ligands conjugated to cytotoxic agents. SUMMARY This receptor family is involved in an increasing number of central nervous system/peripheral processes physiologically and in disease states, and increased understanding of its role may lead to novel treatments.
Collapse
Affiliation(s)
- Nieves Gonzalez
- Digestive Diseases Branch, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | |
Collapse
|
42
|
Bibliography. Current world literature. Growth and development. Curr Opin Endocrinol Diabetes Obes 2008; 15:79-101. [PMID: 18185067 DOI: 10.1097/med.0b013e3282f4f084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|