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Ramos R, Vale N. Dual Drug Repurposing: The Example of Saracatinib. Int J Mol Sci 2024; 25:4565. [PMID: 38674150 PMCID: PMC11050334 DOI: 10.3390/ijms25084565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/11/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024] Open
Abstract
Saracatinib (AZD0530) is a dual Src/Abl inhibitor initially developed by AstraZeneca for cancer treatment; however, data from 2006 to 2024 reveal that this drug has been tested not only for cancer treatment, but also for the treatment of other diseases. Despite the promising pre-clinical results and the tolerability shown in phase I trials, where a maximum tolerated dose of 175 mg was defined, phase II clinical data demonstrated a low therapeutic action against several cancers and an elevated rate of adverse effects. Recently, pre-clinical research aimed at reducing the toxic effects and enhancing the therapeutic performance of saracatinib using nanoparticles and different pharmacological combinations has shown promising results. Concomitantly, saracatinib was repurposed to treat Alzheimer's disease, targeting Fyn. It showed great clinical results and required a lower daily dose than that defined for cancer treatment, 125 mg and 175 mg, respectively. In addition to Alzheimer's disease, this Src inhibitor has also been studied in relation to other health conditions such as pulmonary and liver fibrosis and even for analgesic and anti-allergic functions. Although saracatinib is still not approved by the Food and Drug Administration (FDA), the large number of alternative uses for saracatinib and the elevated number of pre-clinical and clinical trials performed suggest the huge potential of this drug for the treatment of different kinds of diseases.
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Affiliation(s)
- Raquel Ramos
- PerMed Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Nuno Vale
- PerMed Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Community Medicine, Health Information and Decision (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, 4200-450 Porto, Portugal
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2
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Oswald AJ, Symeonides SN, Wheatley D, Chan S, Brunt AM, McAdam K, Schmid P, Waters S, Poole C, Twelves C, Perren T, Bartlett J, Piper T, Chisholm EM, Welsh M, Hill R, Hopcroft LEM, Barrett-Lee P, Cameron DA. Aromatase inhibition plus/minus Src inhibitor saracatinib (AZD0530) in advanced breast cancer therapy (ARISTACAT): a randomised phase II study. Breast Cancer Res Treat 2023; 199:35-46. [PMID: 36859649 PMCID: PMC10147753 DOI: 10.1007/s10549-023-06873-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/31/2023] [Indexed: 03/03/2023]
Abstract
PURPOSE The development of oestrogen resistance is a major challenge in managing hormone-sensitive metastatic breast cancer. Saracatinib (AZD0530), an oral Src kinase inhibitor, prevents oestrogen resistance in animal models and reduces osteoclast activity. We aimed to evaluate the efficacy of saracatinib addition to aromatase inhibitors (AI) in patients with hormone receptor-positive metastatic breast cancer. METHODS This phase II multicentre double-blinded randomised trial allocated post-menopausal women to AI with either saracatinib or placebo (1:1 ratio). Patients were stratified into an "AI-sensitive/naïve" group who received anastrozole and "prior-AI" group who received exemestane. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR) and toxicity. RESULTS 140 patients were randomised from 20 UK centres to saracatinib/AI (n = 69) or placebo/AI (n = 71). Saracatinib was not associated with an improved PFS (3.7 months v. 5.6 months placebo/AI) and did not reduce likelihood of bony progression. There was no benefit in OS or ORR. Effects were consistent in "AI-sensitive/naive" and "prior-AI" sub-groups. Saracatinib was well tolerated with dose reductions in 16% and the main side effects were gastrointestinal, hypophosphatemia and rash. CONCLUSION Saracatinib did not improve outcomes in post-menopausal women with metastatic breast cancer. There was no observed beneficial effect on bone metastases. CRUKE/11/023, ISRCTN23804370.
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Affiliation(s)
| | | | | | - Stephen Chan
- Nottingham University Hospitals NHS Trust, Nottingham, England, UK
| | - Adrian Murray Brunt
- University Hospitals of North Midlands NHS Trust, Stoke-On-Trent & University of Keele, Staffordshire, England, UK
| | - Karen McAdam
- Peterborough City Hospital, Peterborough, England, UK
| | | | - Simon Waters
- Velindre Hospital, Whitchurch, Cardiff, Wales, UK
| | | | - Chris Twelves
- University of Leeds and St James' Hospital, Leeds, England, UK
| | - Timothy Perren
- University of Leeds and St James' Hospital, Leeds, England, UK
| | | | - Tammy Piper
- University of Edinburgh, Edinburgh, Scotland, UK
| | | | - Michelle Welsh
- Scottish Clinical Trials Research Unit, Edinburgh, Scotland, UK
| | - Robert Hill
- Scottish Clinical Trials Research Unit, Edinburgh, Scotland, UK
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3
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Src Family Kinases as Therapeutic Targets in Advanced Solid Tumors: What We Have Learned so Far. Cancers (Basel) 2020; 12:cancers12061448. [PMID: 32498343 PMCID: PMC7352436 DOI: 10.3390/cancers12061448] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 12/17/2022] Open
Abstract
Src is the prototypal member of Src Family tyrosine Kinases (SFKs), a large non-receptor kinase class that controls multiple signaling pathways in animal cells. SFKs activation is necessary for the mitogenic signal from many growth factors, but also for the acquisition of migratory and invasive phenotype. Indeed, oncogenic activation of SFKs has been demonstrated to play an important role in solid cancers; promoting tumor growth and formation of distant metastases. Several drugs targeting SFKs have been developed and tested in preclinical models and many of them have successfully reached clinical use in hematologic cancers. Although in solid tumors SFKs inhibitors have consistently confirmed their ability in blocking cancer cell progression in several experimental models; their utilization in clinical trials has unveiled unexpected complications against an effective utilization in patients. In this review, we summarize basic molecular mechanisms involving SFKs in cancer spreading and metastasization; and discuss preclinical and clinical data highlighting the main challenges for their future application as therapeutic targets in solid cancer progression
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4
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Results of a Randomized, Double-Blinded, Placebo-Controlled, Phase 2.5 Study of Saracatinib (AZD0530), in Patients with Recurrent Osteosarcoma Localized to the Lung. Sarcoma 2020; 2020:7935475. [PMID: 32398945 PMCID: PMC7211262 DOI: 10.1155/2020/7935475] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 01/08/2020] [Indexed: 02/06/2023] Open
Abstract
Purpose Osteosarcoma is a rare cancer and a third of patients who have completed primary treatment will develop osteosarcoma recurrence. The Src pathway has been implicated in the metastatic behavior of osteosarcoma; about 95% of samples examined express Src or have evidence of downstream activation of this pathway. Saracatinib (AZD0530) is a potent and selective Src kinase inhibitor that was evaluated in adults in Phase 1 studies. The primary goal of this study was to determine if treatment with saracatinib could increase progression-free survival (PFS) for patients who have undergone complete resection of osteosarcoma lung metastases in a double-blinded, placebo-controlled trial. Patients and Methods. Subjects with recurrent osteosarcoma localized to lung and who had complete surgical removal of all lung nodules were randomized within six weeks after complete surgical resection. Saracatinib, or placebo, was administered at a dose of 175 mg orally, once daily, for up to thirteen 28-day cycles. Results Thirty-seven subjects were included in the analyses; 18 subjects were randomized to receive saracatinib and 19 to receive placebo. Intent-to-treat analysis demonstrated a median PFS of 19.4 months in the saracatinib treatment group and 8.6 months in the placebo treatment group (p=0.47). Median OS was not reached in either arm. Conclusions Although saracatinib was well tolerated in this patient population, there was no apparent impact of the drug in this double-blinded, placebo-controlled trial on OS, and Src inhibition alone may not be sufficient to suppress metastatic progression in osteosarcoma. There is a suggestion of potential clinical benefit as evidenced by longer PFS in patients randomized to saracatinib based on limited numbers of patients treated.
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5
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Gennari L, Merlotti D, Falchetti A, Eller Vainicher C, Cosso R, Chiodini I. Emerging therapeutic targets for osteoporosis. Expert Opin Ther Targets 2020; 24:115-130. [PMID: 32050822 DOI: 10.1080/14728222.2020.1726889] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Osteoporosis is a chronic, skeletal disorder characterized by compromised bone strength and increased fracture risk; it affects 50% of women and 20% of men. In the past two decades, there have been substantial improvements in the pharmacotherapy of osteoporosis which have yielded potent inhibitors of bone resorption or stimulators of bone formation.Areas covered: This review discusses newly identified targets and pathways and conceptual approaches to the prevention of multiple age-related disorders. Furthermore, it summarizes existing therapeutic strategies for osteoporosis.Expert opinion: Our enhanced understanding of bone biology and the reciprocal interactions between bone and other tissues have allowed the identification of new targets that may facilitate the development of novel drugs. These drugs will hopefully achieve the uncoupling of bone formation from resorption and possibly exert a dual anabolic and antiresorptive effect on bone. Alas, limitations regarding adherence, efficacy on nonvertebral fracture prevention and the long-term adverse events still exist for currently available therapeutics. Moreover, the efficacy of most agents is limited by the tight coupling of osteoblasts and osteoclasts; hence the reduction of bone resorption invariably reduces bone formation, and vice versa. This field is very much 'a work in progress.'
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Affiliation(s)
- Luigi Gennari
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Daniela Merlotti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Alberto Falchetti
- Unit for Bone Metabolism Diseases and Diabetes & Lab of Endocrine and Metabolic Research, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - Cristina Eller Vainicher
- Endocrinology and Diabetology Units, Department of Medical Sciences and Community, Fondazione Ca'Granda Ospedale Maggiore Policlinico IRCCS, Milan, Italy
| | - Roberta Cosso
- EndOsMet Villa Donatello Private Hospital, Florence, Italy
| | - Iacopo Chiodini
- Unit for Bone Metabolism Diseases and Diabetes & Lab of Endocrine and Metabolic Research, Istituto Auxologico Italiano, IRCCS, Milan, Italy
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Danson S, Mulvey MR, Turner L, Horsman J, Escott KJ, Coleman RE, Ahmedzai SH, Bennett MI, Andrew D. An exploratory randomized-controlled trial of the efficacy of the Src-kinase inhibitor saracatinib as a novel analgesic for cancer-induced bone pain. J Bone Oncol 2019; 19:100261. [PMID: 31667062 PMCID: PMC6812043 DOI: 10.1016/j.jbo.2019.100261] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/13/2019] [Accepted: 09/17/2019] [Indexed: 02/04/2023] Open
Abstract
Pain is a major symptom of bone metastases from advanced cancer and represents a clinical challenge to treat effectively. Basic neurobiology in preclinical animal models implicates enhanced sensory processing in the central nervous system, acting through N-methyl-D-aspartate (NMDA) glutamate receptors, as an important mechanism underpinning persistent pain. The non-receptor tyrosine kinase Src is thought to act as a hub for regulating NMDA receptor activity and the orally available Src inhibitor saracatinib has shown promise as a potential analgesic in recent animal studies. Here we tested the efficacy of saracatinib as a novel analgesic in an exploratory phase II randomized controlled trial on cancer patients with painful bone metastases. Twelve patients completed the study, with 6 receiving saracatinib 125 mg/day for 28 days and 6 receiving placebo. Pharmacokinetic measurements confirmed appropriate plasma levels of drug in the saracatinib-treated group and Src inhibition was achieved clinically by a significant reduction in the bone resorption biomarker serum cross-linked C-terminal telopeptide of type I collagen. Differences between the saracatinib and placebo groups self-reported pain scores, measured using the short form of the Brief Pain Inventory, were not clinically significant after 4 weeks of treatment. There was also no change in consumption of maintenance analgesia in the saracatinib-treated group and no improvement in Quality-of-Life scores. The data were insufficient to demonstrate saracatinib has efficacy as analgesic, although it may have a role as an anti-bone resorptive agent.
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Affiliation(s)
- Sarah Danson
- Academic Unit of Clinical Oncology, Sheffield Experimental Cancer Medicine Centre, Weston Park Hospital, University of Sheffield, UK
| | - Matthew R Mulvey
- Academic Unit of Palliative Care, Leeds Institute of Health Sciences, University of Leeds, UK
| | - Lesley Turner
- Academic Unit of Clinical Oncology, Sheffield Experimental Cancer Medicine Centre, Weston Park Hospital, University of Sheffield, UK
| | - Janet Horsman
- Academic Unit of Clinical Oncology, Sheffield Experimental Cancer Medicine Centre, Weston Park Hospital, University of Sheffield, UK
| | - KJane Escott
- Emerging Innovations Unit, BioPharmaceuticals R & D, AstraZeneca, Cambridge, UK
| | - Robert E Coleman
- Academic Unit of Clinical Oncology, Sheffield Experimental Cancer Medicine Centre, Weston Park Hospital, University of Sheffield, UK
| | | | - Michael I Bennett
- Academic Unit of Palliative Care, Leeds Institute of Health Sciences, University of Leeds, UK
| | - David Andrew
- School of Clinical Dentistry, University of Sheffield, UK
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7
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Thouverey C, Ferrari S, Caverzasio J. Selective inhibition of Src family kinases by SU6656 increases bone mass by uncoupling bone formation from resorption in mice. Bone 2018; 113:95-104. [PMID: 29751129 DOI: 10.1016/j.bone.2018.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/25/2018] [Accepted: 05/07/2018] [Indexed: 01/08/2023]
Abstract
Mice deficient in the non-receptor tyrosine kinase Src exhibit high bone mass due to impaired bone resorption and increased bone formation. Although several Src family kinase inhibitors inhibit bone resorption in vivo, they display variable effects on bone formation. SU6656 is a selective Src family kinase inhibitor with weaker activity towards the non-receptor tyrosine kinase Abl and receptor tyrosine kinases which are required for appropriate osteoblast proliferation, differentiation and function. Therefore, we sought to determine whether SU6656 could increase bone mass by inhibiting bone resorption and by stimulating bone formation, and to explore its mechanisms of action. Four-month-old female C57Bl/6J mice received intraperitoneal injections of either 25 mg/kg SU6656 or its vehicle every other day for 12 weeks. SU6656-treated mice exhibited increased bone mineral density, cortical thickness, cancellous bone volume and trabecular thickness. SU6656 inhibited bone resorption in mice as shown by reduced osteoclast number, and diminished expressions of Oscar, Trap5b and CtsK. SU6656 did not affect Rankl or Opg expressions. However, it blocked c-fms signaling, osteoclastogenesis and matrix resorption, and induced osteoclast apoptosis in vitro. In addition, SU6656 stimulated bone formation rates at trabecular, endosteal and periosteal bone envelopes, and increased osteoblast number in trabecular bone. SU6656 did not affect expressions of clastokines favoring bone formation in mice. However, it stimulated osteoblast differentiation and matrix mineralization by specifically facilitating BMP-SMAD signaling pathway in vitro. Knockdown of Src and Yes mimicked the stimulatory effect of SU6656 on osteoblast differentiation. In conclusion, SU6656 uncouples bone formation from resorption by inhibiting osteoclast development, function and survival, and by enhancing BMP-mediated osteoblast differentiation.
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Affiliation(s)
- Cyril Thouverey
- Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, 1205 Geneva, Switzerland.
| | - Serge Ferrari
- Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, 1205 Geneva, Switzerland
| | - Joseph Caverzasio
- Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, 1205 Geneva, Switzerland
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8
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Woodcock VK, Clive S, Wilson RH, Coyle VM, Stratford MRL, Folkes LK, Eastell R, Barton C, Jones P, Kazmi-Stokes S, Turner H, Halford S, Harris AL, Middleton MR. A first-in-human phase I study to determine the maximum tolerated dose of the oral Src/ABL inhibitor AZD0424. Br J Cancer 2018; 118:770-776. [PMID: 29438361 PMCID: PMC5877436 DOI: 10.1038/bjc.2017.484] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/09/2017] [Accepted: 12/12/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Src is involved in cancer invasion and metastasis. AZD0424, an oral inhibitor of Src and ABL1, has shown evidence of anti-tumour activity in pre-clinical studies. METHODS A phase Ia, dose escalation study was performed to assess the safety of continuous oral dosing with AZD0424 in advanced solid tumours. Secondary objectives included investigation of AZD0424 pharmacokinetics, effect on Src activity using markers of bone turnover, and anti-tumour activity. RESULTS 41 patients were treated; 34 received AZD0424 once-daily at doses ranging from 5 mg to 150 mg, and 7 received 40 mg bi-daily 41.5% of patients experienced at least one AZD0424-related adverse event that was Grade 3-5 in severity, with patients treated at doses above 60 mg per day experiencing multiple treatment-related toxicities. The most commonly observed AZD0424-related adverse events were nausea, fatigue, anorexia and alopecia. Cmax and AUC increased linearly with dose and the mean±standard deviation t1/2 was 8.4±2.8 h. Clear evidence of Src target inhibition was seen at doses ⩾20 mg per day. No responses were observed and 7 patients (17.1%) achieved stable disease lasting 6 weeks or more. CONCLUSIONS AZD0424 displayed no evidence of efficacy as monotherapy despite a clear pharmacodynamic effect. Further evaluation of AZD0424 monotherapy in patients with solid tumours is not recommended.
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Affiliation(s)
- Victoria K Woodcock
- University of Oxford Department of Oncology, Churchill Hospital, Old Road, Oxford OX3 7LJ, UK
| | - Sally Clive
- Edinburgh Cancer Centre, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Richard H Wilson
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK
| | - Vicky M Coyle
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK
| | - Michael R L Stratford
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Lisa K Folkes
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Richard Eastell
- Academic Unit of Bone Metabolism, University of Sheffield, Sheffield S10 2TN, UK
| | - Claire Barton
- Cancer Research UK Centre for Drug Development, Cancer Research UK, Angel Building, 407 St. John Street, London EC1V 4AD, UK
| | - Paul Jones
- Cancer Research UK Centre for Drug Development, Cancer Research UK, Angel Building, 407 St. John Street, London EC1V 4AD, UK
| | - Shamim Kazmi-Stokes
- Cancer Research UK Centre for Drug Development, Cancer Research UK, Angel Building, 407 St. John Street, London EC1V 4AD, UK
| | - Helen Turner
- Cancer Research UK Centre for Drug Development, Cancer Research UK, Angel Building, 407 St. John Street, London EC1V 4AD, UK
| | - Sarah Halford
- Cancer Research UK Centre for Drug Development, Cancer Research UK, Angel Building, 407 St. John Street, London EC1V 4AD, UK
| | - Adrian L Harris
- University of Oxford Department of Oncology, Churchill Hospital, Old Road, Oxford OX3 7LJ, UK
| | - Mark R Middleton
- University of Oxford Department of Oncology, Churchill Hospital, Old Road, Oxford OX3 7LJ, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford OX3 7LE, UK
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9
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Heusschen R, Muller J, Binsfeld M, Marty C, Plougonven E, Dubois S, Mahli N, Moermans K, Carmeliet G, Léonard A, Baron F, Beguin Y, Menu E, Cohen-Solal M, Caers J. SRC kinase inhibition with saracatinib limits the development of osteolytic bone disease in multiple myeloma. Oncotarget 2017; 7:30712-29. [PMID: 27095574 PMCID: PMC5058712 DOI: 10.18632/oncotarget.8750] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 03/31/2016] [Indexed: 12/17/2022] Open
Abstract
Multiple myeloma (MM)-associated osteolytic bone disease is a major cause of morbidity and mortality in MM patients and the development of new therapeutic strategies is of great interest. The proto-oncogene SRC is an attractive target for such a strategy. In the current study, we investigated the effect of treatment with the SRC inhibitor saracatinib (AZD0530) on osteoclast and osteoblast differentiation and function, and on the development of MM and its associated bone disease in the 5TGM.1 and 5T2MM murine MM models. In vitro data showed an inhibitory effect of saracatinib on osteoclast differentiation, polarization and resorptive function. In osteoblasts, collagen deposition and matrix mineralization were affected by saracatinib. MM cell proliferation and tumor burden remained unaltered following saracatinib treatment and we could not detect any synergistic effects with drugs that are part of standard care in MM. We observed a marked reduction of bone loss after treatment of MM-bearing mice with saracatinib as reflected by a restoration of trabecular bone parameters to levels observed in naive control mice. Histomorphometric analyses support that this occurs through an inhibition of bone resorption. In conclusion, these data further establish SRC inhibition as a promising therapeutic approach for the treatment of MM-associated osteolytic bone disease.
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Affiliation(s)
- Roy Heusschen
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium
| | - Joséphine Muller
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium
| | - Marilène Binsfeld
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium
| | - Caroline Marty
- INSERM-UMR-1132, Hôpital Lariboisière and Université Paris Diderot, Paris, France
| | - Erwan Plougonven
- Department of Chemical Engineering, PEPs (Products, Environments, Processes), University of Liège, Liège, Belgium
| | - Sophie Dubois
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium
| | - Nadia Mahli
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium
| | - Karen Moermans
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Angélique Léonard
- Department of Chemical Engineering, PEPs (Products, Environments, Processes), University of Liège, Liège, Belgium
| | - Frédéric Baron
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium.,Division of Hematology, Department of Medicine, University and CHU of Liège, Liège, Belgium
| | - Yves Beguin
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium.,Division of Hematology, Department of Medicine, University and CHU of Liège, Liège, Belgium
| | - Eline Menu
- Department of Hematology and Immunology, Myeloma Center Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Martine Cohen-Solal
- INSERM-UMR-1132, Hôpital Lariboisière and Université Paris Diderot, Paris, France
| | - Jo Caers
- Laboratory of Hematology, GIGA-Research, University of Liège, Liège, Belgium.,Division of Hematology, Department of Medicine, University and CHU of Liège, Liège, Belgium
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10
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Xiong J, Wu JS, Mao SS, Yu XN, Huang XX. Effect of saracatinib on pulmonary metastases from hepatocellular carcinoma. Oncol Rep 2016; 36:1483-90. [PMID: 27460949 DOI: 10.3892/or.2016.4968] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/31/2016] [Indexed: 11/06/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Src is involved in multiple processes of cancer metastasis; however, its significance in HCC is not well defined. In the present study, overexpression of Src phosphorylation (Y416) was observed in the highly metastatic MHCC97H cell line; additionally, through inhibition of Src kinase activation, HCC cell proliferation, migration, invasion and colony formation were significantly reduced in vitro. Tumour growth was not affected in the orthotopic xenograft HCC model, but the metastasic potential was inhibited as revealed by reduced lung metastasic foci after administration of saracatinib. Phosphorylation level of Src pathway signalling molecules, such as Src, FAK and Stat3, were also reduced in vitro and in vivo, as a result of the anti-metastasic effects caused by saracatinib treatment. In conclusion, we demonstrated the pro-metastasic role of Src in HCC, and further experiments suggest the use of the Src inhibitor in combination with cytotoxic agents and other anticancer treatments to improve HCC prognosis.
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Affiliation(s)
- Ju Xiong
- Department of General Surgery, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi 830001, P.R. China
| | - Jin-Sheng Wu
- Department of Oncology, Hainan Nonken Nada Hospital, Danzhou, Hainan 571700, P.R. China
| | - Shan-Shan Mao
- Department of Gastroenterology, Haikou People's Hospital Affiliated to Central South University, Xiangya School of Medicine, Haikou 570028, P.R. China
| | - Xiang-Nan Yu
- Department of Gastroenterology, Haikou People's Hospital Affiliated to Central South University, Xiangya School of Medicine, Haikou 570028, P.R. China
| | - Xiao-Xi Huang
- Department of Gastroenterology, Haikou People's Hospital Affiliated to Central South University, Xiangya School of Medicine, Haikou 570028, P.R. China
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11
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De Felice M, Lambert D, Holen I, Escott KJ, Andrew D. Effects of Src-kinase inhibition in cancer-induced bone pain. Mol Pain 2016; 12:12/0/1744806916643725. [PMID: 27094550 PMCID: PMC4956174 DOI: 10.1177/1744806916643725] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/14/2016] [Indexed: 12/16/2022] Open
Abstract
Background Bone metastases occur frequently in advanced breast, lung, and prostate cancer, with approximately 70% of patients affected. Pain is a major symptom of bone metastases, and current treatments may be inadequate or have unacceptable side effects. The mechanisms that drive cancer-induced bone pain are not fully understood; however, it is known that there is sensitization of both peripheral bone afferents and central spinal circuits. It is well established that the N-methyl-D-aspartate receptor plays a major role in the pathophysiology of pain hypersensitivity. Inhibition of the non-receptor tyrosine kinase Src controls N-methyl-D-aspartate receptor activity and inhibiting Src reduces the hypersensitivity associated with neuropathic and inflammatory pains. As Src is also implicated in osteoclastic bone resorption, we have investigated if inhibiting Src ameliorates cancer-induced bone pain. We have tested this hypothesis using an orally bioavailable Src inhibitor (saracatinib) in a rat model of cancer-induced bone pain. Results Intra-tibial injection of rat mammary cancer cells (Mammary rat metastasis tumor cells -1), but not vehicle, in rats produced hindpaw hypersensitivity to thermal and mechanical stimuli that was maximal after six days and persisted for at least 13 days postinjection. Daily oral gavage with saracatinib (20 mg/kg) beginning seven days after intra-tibial injection reversed the thermal hyperalgesia but not the mechanical allodynia. The analgesic mechanisms of saracatinib appear to be due to an effect on the nervous system as immunoblotting of L2-5 spinal segments showed that mammary rat metastasis tumor cells-1 injection induced phosphorylation of the GluN1 subunit of the N-methyl-D-aspartate receptor, indicative of receptor activation, and this was reduced by saracatinib. Additionally, histology showed no anti-tumor effect of saracatinib at any dose and no significant effect on bone preservation. Conclusions This is the first demonstration that Src plays a role in the development of cancer-induced bone pain and that Src inhibition represents a possible new analgesic strategy for patients with bone metastases.
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Affiliation(s)
| | - Daniel Lambert
- School of Clinical Dentistry, University of Sheffield, UK
| | - Ingunn Holen
- Department of Oncology, University of Sheffield, UK
| | - K Jane Escott
- Scientific Partnering and Alliances, AstraZeneca, Alderley Park, UK
| | - David Andrew
- School of Clinical Dentistry, University of Sheffield, UK
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12
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Rachner TD, Jakob F, Hofbauer LC. Cancer-targeted therapies and radiopharmaceuticals. BONEKEY REPORTS 2015; 4:707. [PMID: 26131359 DOI: 10.1038/bonekey.2015.76] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 04/16/2015] [Indexed: 12/26/2022]
Abstract
The treatment of bone metastases remains a clinical challenge. Although a number of well-established agents, namely bisphosphonates and denosumab, are available to reduce the occurrence of skeletal-related events, additional cancer-targeted therapies are required to improve patients' prognosis and quality of life. This review focuses on novel targets and agents that are under clinical evaluation for the treatment of malignant bone diseases such as activin A, src and endothelin-1 inhibition or agents that are clinically approved and may positively influence bone, such as the mTOR inhibitor everolimus. In addition, the potential of alpharadin, a novel radiopharmaceutical approved for the treatment of prostatic bone disease, is discussed.
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Affiliation(s)
- Tilman D Rachner
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine III, Dresden University Medical Center , Dresden, Germany
| | - Franz Jakob
- Orthopedic Center for Musculoskeletal Research, University Hospital Wuerzburg , Wuerzburg, Germany
| | - Lorenz C Hofbauer
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine III, Dresden University Medical Center , Dresden, Germany ; Center for Regenerative Therapies, Dresden Technical University , Dresden, Germany
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13
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Nygaard HB, Wagner AF, Bowen GS, Good SP, MacAvoy MG, Strittmatter KA, Kaufman AC, Rosenberg BJ, Sekine-Konno T, Varma P, Chen K, Koleske AJ, Reiman EM, Strittmatter SM, van Dyck CH. A phase Ib multiple ascending dose study of the safety, tolerability, and central nervous system availability of AZD0530 (saracatinib) in Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2015; 7:35. [PMID: 25874001 PMCID: PMC4396171 DOI: 10.1186/s13195-015-0119-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/16/2015] [Indexed: 12/31/2022]
Abstract
Introduction Despite significant progress, a disease-modifying therapy for Alzheimer’s disease (AD) has not yet been developed. Recent findings implicate soluble oligomeric amyloid beta as the most relevant protein conformation in AD pathogenesis. We recently described a signaling cascade whereby oligomeric amyloid beta binds to cellular prion protein on the neuronal cell surface, activating intracellular Fyn kinase to mediate synaptotoxicity. Fyn kinase has been implicated in AD pathophysiology both in in vitro models and in human subjects, and is a promising new therapeutic target for AD. Herein, we present a Phase Ib trial of the repurposed investigational drug AZD0530, a Src family kinase inhibitor specific for Fyn and Src kinase, for the treatment of patients with mild-to-moderate AD. Methods The study was a 4-week Phase Ib multiple ascending dose, randomized, double-blind, placebo-controlled trial of AZD0530 in AD patients with Mini-Mental State Examination (MMSE) scores ranging from 16 to 26. A total of 24 subjects were recruited in three sequential groups, with each randomized to receive oral AZD0530 at doses of 50 mg, 100 mg, 125 mg, or placebo daily for 4 weeks. The drug:placebo ratio was 3:1. Primary endpoints were safety, tolerability, and cerebrospinal fluid (CSF) penetration of AZD0530. Secondary endpoints included changes in clinical efficacy measures (Alzheimer’s Disease Assessment Scale – cognitive subscale, MMSE, Alzheimer’s Disease Cooperative Study – Activities of Daily Living Inventory, Neuropsychiatric Inventory, and Clinical Dementia Rating Scale – Sum of Boxes) and regional cerebral glucose metabolism measured by fluorodeoxyglucose positron emission tomography. Results AZD0530 was generally safe and well tolerated across doses. One subject receiving 125 mg of AZD0530 was discontinued from the study due to the development of congestive heart failure and atypical pneumonia, which were considered possibly related to the study drug. Plasma/CSF ratio of AZD0530 was 0.4. The 100 mg and 125 mg doses achieved CSF drug levels corresponding to brain levels that rescued memory deficits in transgenic mouse models. One-month treatment with AZD0530 had no significant effect on clinical efficacy measures or regional cerebral glucose metabolism. Conclusions AZD0530 is reasonably safe and well tolerated in patients with mild-to-moderate AD, achieving substantial central nervous system penetration with oral dosing at 100–125 mg. Targeting Fyn kinase may be a promising therapeutic approach in AD, and a larger Phase IIa clinical trial of AZD0530 for the treatment of patients with AD has recently launched. Trial registration ClinicalTrials.gov: NCT01864655. Registered 12 June 2014.
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Affiliation(s)
- Haakon B Nygaard
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut USA ; Program in Cellular Neuroscience, Neurodegeneration and Repair (CNNR), Yale University School of Medicine, New Haven, Connecticut USA ; Current address: University of British Columbia, Division of Neurology, Djavad Mowafaghian Centre for Brain Health, Vancouver, Canada
| | - Allison F Wagner
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut USA
| | - Garrett S Bowen
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut USA
| | - Susan P Good
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut USA
| | - Martha G MacAvoy
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut USA
| | - Kurt A Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration and Repair (CNNR), Yale University School of Medicine, New Haven, Connecticut USA
| | - Adam C Kaufman
- Program in Cellular Neuroscience, Neurodegeneration and Repair (CNNR), Yale University School of Medicine, New Haven, Connecticut USA
| | - Brian J Rosenberg
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut USA
| | - Tomoko Sekine-Konno
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut USA
| | - Pradeep Varma
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut USA
| | - Kewei Chen
- Banner Alzheimer's Institute, Phoenix, Arizona USA
| | - Anthony J Koleske
- Program in Cellular Neuroscience, Neurodegeneration and Repair (CNNR), Yale University School of Medicine, New Haven, Connecticut USA ; Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut USA
| | | | - Stephen M Strittmatter
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut USA ; Program in Cellular Neuroscience, Neurodegeneration and Repair (CNNR), Yale University School of Medicine, New Haven, Connecticut USA
| | - Christopher H van Dyck
- Alzheimer's Disease Research Unit, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut USA ; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut USA
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Erdogan B, Cicin I. Medical treatment of breast cancer bone metastasis: from bisphosphonates to targeted drugs. Asian Pac J Cancer Prev 2014; 15:1503-10. [PMID: 24641358 DOI: 10.7314/apjcp.2014.15.4.1503] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Breast cancer bone metastasis causing severe morbidity is commonly encountered in daily clinical practice. It causes pain, pathologic fractures, spinal cord and other nerve compression syndromes and life threatening hypercalcemia. Breast cancer metastasizes to bone through complicated steps in which numerous molecules play roles. Metastatic cells disrupt normal bone turnover and create a vicious cycle to which treatment efforts should be directed. Bisphosphonates have been used safely for more than two decades. As a group they delay time to first skeletal related event and reduce pain, but do not prevent development of bone metastasis in patients with no bone metastasis, and also do not prolong survival. The receptor activator for nuclear factor κB ligand inhibitor denosumab delays time to first skeletal related event and reduces the skeletal morbidity rate. Radionuclides are another treatment option for bone pain. New targeted therapies and radionuclides are still under investigation. In this review we will focus on mechanisms of bone metastasis and its medical treatment in breast cancer patients.
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Affiliation(s)
- Bulent Erdogan
- Departments of Medical Oncology, Agri State Hospital, Turkey E-mail :
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15
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McNeish IA, Ledermann JA, Webber L, James L, Kaye SB, Hall M, Hall G, Clamp A, Earl H, Banerjee S, Kristeleit R, Raja F, Feeney A, Lawrence C, Dawson-Athey L, Persic M, Khan I. A randomised, placebo-controlled trial of weekly paclitaxel and saracatinib (AZD0530) in platinum-resistant ovarian, fallopian tube or primary peritoneal cancer†. Ann Oncol 2014; 25:1988-1995. [PMID: 25070546 DOI: 10.1093/annonc/mdu363] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND We investigated whether the Src inhibitor saracatinib (AZD0530) improved efficacy of weekly paclitaxel in platinum-resistant ovarian cancer. PATIENTS AND METHODS Patients with platinum-resistant ovarian, fallopian tube or primary peritoneal cancer were randomised 2 : 1 to receive 8-week cycles of weekly paclitaxel (wPxl; 80 mg/m(2)/week ×6 with 2-week break) plus saracatinib (S; 175 mg o.d.) or placebo (P) continuously, starting 1 week before wPxl, until disease progression. Patients were stratified by taxane-free interval (<6 versus ≥6 months/no prior taxane). The primary end point was progression-free survival (PFS) rate at 6 months. Secondary end points included overall survival (OS) and response rate (RR). RESULTS A total of 107 patients, median age 63 years, were randomised. Forty-three (40%) had received >2 lines of prior chemotherapy. The 6-month PFS rate was 29% (wPxl + S) versus 34% (wPxl + P) (P = 0.582). Median PFS was 4.7 versus 5.3 months (hazard ratio 1.00, 95% confidence interval 0.65-1.54; P = 0.99). RR (complete + partial) was 29% (wPxl + S) versus 43% (wPxl + P), P value = 0.158. Grade 3/4 adverse events were 36% versus 31% (P = 0.624); the most frequent G3/4 toxicities were vomiting (5.8% saracatinib versus 8.6% placebo), abdominal pain (5.8% versus 0%) and diarrhoea (4.3% versus 5.7%). Febrile neutropenia was more common in the saracatinib arm (4.3%) than placebo (0%). Response, PFS and OS were all significantly (P < 0.05) better in patients with taxane interval ≥6 months/no prior taxane (n = 85) than those <6 months (n = 22), regardless of randomisation. CONCLUSIONS Saracatinib does not improve activity of weekly paclitaxel in platinum-resistant ovarian cancer. Taxane-free interval of ≥6 months/no prior taxane was associated with better outcome in both groups. TRIALS REGISTRATION Clinicaltrials.gov NCT01196741; ISRCTN 32163062.
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Affiliation(s)
- I A McNeish
- Institute of Cancer Sciences, University of Glasgow, Glasgow; Department of Medical Oncology, St Bartholomew's Hospital, London.
| | - J A Ledermann
- CR UK and UCL Cancer Trials Centre, University College London, London
| | - L Webber
- CR UK and UCL Cancer Trials Centre, University College London, London
| | - L James
- CR UK and UCL Cancer Trials Centre, University College London, London
| | - S B Kaye
- Department of Medical Oncology, Royal Marsden Hospital, Sutton
| | - M Hall
- Division of Cancer Services, Mount Vernon Hospital, Northwood
| | - G Hall
- Leeds Cancer Centre, St James's University Hospital, Leeds
| | - A Clamp
- Department of Medical Oncology, The Christie Hospital, Manchester
| | - H Earl
- Department of Oncology, Addenbrooke's Hospital, Cambridge
| | - S Banerjee
- Department of Medical Oncology, Royal Marsden Hospital, Sutton
| | - R Kristeleit
- Department of Medical Oncology, University College Hospital, London
| | - F Raja
- CR UK and UCL Cancer Trials Centre, University College London, London
| | - A Feeney
- CR UK and UCL Cancer Trials Centre, University College London, London
| | - C Lawrence
- Department of Medical Oncology, St Bartholomew's Hospital, London
| | - L Dawson-Athey
- Department of Medical Oncology, St Bartholomew's Hospital, London
| | - M Persic
- Department of Oncology, Queen's Hospital, Burton upon Trent, UK
| | - I Khan
- CR UK and UCL Cancer Trials Centre, University College London, London
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16
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Alemán JO, Farooki A, Girotra M. Effects of tyrosine kinase inhibition on bone metabolism: untargeted consequences of targeted therapies. Endocr Relat Cancer 2014; 21:R247-59. [PMID: 24478055 DOI: 10.1530/erc-12-0400] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tyrosine kinase inhibitors (TKIs) are at the forefront of molecular-targeted therapies for cancer. With the advent of imatinib for the treatment of chronic myelogenous leukemia, a new wave of small-molecule therapeutics redefined the oncologic treatment to become chronically administered medications with tolerable side-effect profiles compared with cytotoxic agents. Effects on bone mineral metabolism were observed during early imatinib treatment, in the form of hypophosphatemia with increased urinary phosphorus excretion. This finding led to detailed investigations of off-target effects responsible for changes in bone cell maturation, activity, and impact on bone mass. Subsequently, another BCR-Abl inhibitor (dasatinib), vascular endothelial growth factor (VEGF) inhibitors (sorafenib and sunitinib) as well as rearranged during transfection (RET) inhibitors (vandetanib and cabozantinib) were developed. Inhibition of bone resorption appears to be a class effect and is likely contributed by TKI effects on the hematopoietic and mesenchymal stem cells. As long-term, prospective, clinical outcomes data accumulate on these targeted therapies, the full extent of off-target side effects on bone health will need to be considered along with the significant benefits of tyrosine kinase inhibition in oncologic treatment.
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Affiliation(s)
- José O Alemán
- Endocrine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Weill Cornell Medical College, New York, New York 10065, USA
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Mechanical loading in osteocytes induces formation of a Src/Pyk2/MBD2 complex that suppresses anabolic gene expression. PLoS One 2014; 9:e97942. [PMID: 24841674 PMCID: PMC4026426 DOI: 10.1371/journal.pone.0097942] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/25/2014] [Indexed: 11/19/2022] Open
Abstract
Mechanical stimulation of the skeleton promotes bone gain and suppresses bone loss, ultimately resulting in improved bone strength and fracture resistance. The molecular mechanisms directing anabolic and/or anti-catabolic actions on the skeleton during loading are not fully understood. Identifying molecular mechanisms of mechanotransduction (MTD) signaling cascades could identify new therapeutic targets. Most research into MTD mechanisms is typically focused on understanding the signaling pathways that stimulate new bone formation in response to load. However, we investigated the structural, signaling and transcriptional molecules that suppress the stimulatory effects of loading. The high bone mass phenotype of mice with global deletion of either Pyk2 or Src suggests a role for these tyrosine kinases in repression of bone formation. We used fluid shear stress as a MTD stimulus to identify a novel Pyk2/Src-mediated MTD pathway that represses mechanically-induced bone formation. Our results suggest Pyk2 and Src function as molecular switches that inhibit MTD in our mechanically stimulated osteocyte culture experiments. Once activated by oscillatory fluid shear stress (OFSS), Pyk2 and Src translocate to and accumulate in the nucleus, where they associate with a protein involved in DNA methylation and the interpretation of DNA methylation patterns –methyl-CpG-binding domain protein 2 (MBD2). OFSS-induced Cox-2 and osteopontin expression was enhanced in Pyk2 KO osteoblasts, while inhibition of Src enhanced osteocalcin expression in response to OFSS. We found that Src kinase activity increased in the nucleus of osteocytes in response to OFSS and an interaction activated between Src (Y418) and Pyk2 (Y402) increased in response to OFSS. Thus, as a mechanism to prevent an over-reaction to physical stimulation, mechanical loading may induce the formation of a Src/Pyk2/MBD2 complex in the nucleus that functions to suppress anabolic gene expression.
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19
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Siemann DW, Dong M, Pampo C, Shi W. Src-signaling interference impairs the dissemination of blood-borne tumor cells. Cell Tissue Res 2012; 349:541-50. [PMID: 22526632 DOI: 10.1007/s00441-012-1415-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 03/19/2012] [Indexed: 12/21/2022]
Abstract
Although solid tumors continuously shed cells, only a small fraction of the neoplastic cells that enter the blood stream are capable of establishing metastases. In order to be successful, these cells must attach, extravasate, proliferate and induce angiogenesis. Preclinical studies have shown that small-molecule ATP-competitive Src kinase inhibitors can effectively impair metastasis-associated tumor cell functions in vitro. However, the impact of these agents on the metastatic cascade in vivo is less well understood. In the present studies, we have examined the ability of saracatinib, a dual-specific, orally available inhibitor of Src and Abl protein tyrosine kinases, to interfere with the establishment of lung metastases in mice by tumor cells introduced into the blood stream. The results demonstrate that Src inhibition most effectively interferes with the establishment of secondary tumor deposits when treatments are administered while tumor cells are in the initial phases of dissemination.
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Affiliation(s)
- Dietmar W Siemann
- Department of Radiation Oncology and Shands Cancer Center, University of Florida, 2000 SW Archer Road, Gainesville, FL 32610, USA.
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