1
|
Tikum AF, Ketchemen JP, Doroudi A, Nambisan AK, Babeker H, Njotu FN, Fonge H. Effectiveness of 225Ac-Labeled Anti-EGFR Radioimmunoconjugate in EGFR-Positive Kirsten Rat Sarcoma Viral Oncogene and BRAF Mutant Colorectal Cancer Models. J Nucl Med 2024:jnumed.123.266204. [PMID: 38360051 DOI: 10.2967/jnumed.123.266204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 01/05/2024] [Indexed: 02/17/2024] Open
Abstract
Eighty percent of colorectal cancers (CRCs) overexpress epidermal growth factor receptor (EGFR). Kirsten rat sarcoma viral oncogene (KRAS) mutations are present in 40% of CRCs and drive de novo resistance to anti-EGFR drugs. BRAF oncogene is mutated in 7%-10% of CRCs, with even worse prognosis. We have evaluated the effectiveness of [225Ac]Ac-macropa-nimotuzumab in KRAS mutant and in KRAS wild-type and BRAFV600E mutant EGFR-positive CRC cells in vitro and in vivo. Anti-CD20 [225Ac]Ac-macropa-rituximab was developed and used as a nonspecific radioimmunoconjugate. Methods: Anti-EGFR antibody nimotuzumab was radiolabeled with 225Ac via an 18-membered macrocyclic chelator p-SCN-macropa. The immunoconjugate was characterized using flow cytometry, radioligand binding assay, and high-performance liquid chromatography, and internalization was studied using live-cell imaging. In vitro cytotoxicity was evaluated in 2-dimensional monolayer EGFR-positive KRAS mutant DLD-1, SW620, and SNU-C2B; in KRAS wild-type and BRAFV600E mutant HT-29 CRC cell lines; and in 3-dimensional spheroids. Dosimetry was studied in healthy mice. The in vivo efficacy of [225Ac]Ac-macropa-nimotuzumab was evaluated in mice bearing DLD-1, SW620, and HT-29 xenografts after treatment with 3 doses of 13 kBq/dose administered 10 d apart. Results: In all cell lines, in vitro studies showed enhanced cytotoxicity of [225Ac]Ac-macropa-nimotuzumab compared with nimotuzumab and controls. The inhibitory concentration of 50% in the DLD-1 cell line was 1.8 nM for [225Ac]Ac-macropa-nimotuzumab versus 84.1 nM for nimotuzumab. Similarly, the inhibitory concentration of 50% was up to 79-fold lower for [225Ac]Ac-macropa-nimotuzumab than for nimotuzumab in KRAS mutant SNU-C2B and SW620 and in KRAS wild-type and BRAFV600E mutant HT-29 CRC cell lines. A similar trend was observed for 3-dimensional spheroids. Internalization peaked 24-48 h after incubation and depended on EGFR expression. In the [225Ac]Ac-macropa-nimotuzumab group, 3 of 7 mice bearing DLD-1 tumors had complete remission. Median survival was 40 and 34 d for mice treated with phosphate-buffered saline and [225Ac]Ac-macropa-rituximab (control), respectively, whereas it was not reached for the [225Ac]Ac-macropa-nimotuzumab group (>90 d). Similarly, median survival of mice bearing HT-29 xenografts was 16 and 12.5 d for those treated with [225Ac]Ac-macropa-rituximab and phosphate-buffered saline, respectively, and was not reached for those treated with [225Ac]Ac-macropa-nimotuzumab (>90 d). One of 7 mice bearing HT-29 xenografts and treated using [225Ac]Ac-macropa-nimotuzumab had complete remission. Compared with untreated mice, [225Ac]Ac-macropa-nimotuzumab more than doubled (16 vs. 41 d) the median survival of mice bearing SW620 xenografts. Conclusion: [225Ac]Ac-macropa-nimotuzumab is effective against KRAS mutant and BRAFV600E mutant CRC models.
Collapse
Affiliation(s)
- Anjong Florence Tikum
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jessica P Ketchemen
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alireza Doroudi
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Anand K Nambisan
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Hanan Babeker
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; and
| | - Fabrice Ngoh Njotu
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada;
- Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, Saskatchewan, Canada
| |
Collapse
|
2
|
Coll RP, Bright SJ, Martinus DKJ, Georgiou DK, Sawakuchi GO, Manning HC. Alpha Particle-Emitting Radiopharmaceuticals as Cancer Therapy: Biological Basis, Current Status, and Future Outlook for Therapeutics Discovery. Mol Imaging Biol 2023; 25:991-1019. [PMID: 37845582 DOI: 10.1007/s11307-023-01857-y] [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: 06/26/2023] [Revised: 09/03/2023] [Accepted: 09/05/2023] [Indexed: 10/18/2023]
Abstract
Critical advances in radionuclide therapy have led to encouraging new options for cancer treatment through the pairing of clinically useful radiation-emitting radionuclides and innovative pharmaceutical discovery. Of the various subatomic particles used in therapeutic radiopharmaceuticals, alpha (α) particles show great promise owing to their relatively large size, delivered energy, finite pathlength, and resulting ionization density. This review discusses the therapeutic benefits of α-emitting radiopharmaceuticals and their pairing with appropriate diagnostics, resulting in innovative "theranostic" platforms. Herein, the current landscape of α particle-emitting radionuclides is described with an emphasis on their use in theranostic development for cancer treatment. Commonly studied radionuclides are introduced and recent efforts towards their production for research and clinical use are described. The growing popularity of these radionuclides is explained through summarizing the biological effects of α radiation on cancer cells, which include DNA damage, activation of discrete cell death programs, and downstream immune responses. Examples of efficient α-theranostic design are described with an emphasis on strategies that lead to cellular internalization and the targeting of proteins involved in therapeutic resistance. Historical barriers to the clinical deployment of α-theranostic radiopharmaceuticals are also discussed. Recent progress towards addressing these challenges is presented along with examples of incorporating α-particle therapy in pharmaceutical platforms that can be easily converted into diagnostic counterparts.
Collapse
Affiliation(s)
- Ryan P Coll
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA
| | - Scott J Bright
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - David K J Martinus
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - Dimitra K Georgiou
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA
| | - Gabriel O Sawakuchi
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - H Charles Manning
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA.
- Cyclotron Radiochemistry Facility, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA.
| |
Collapse
|
3
|
Prasad A, Nair R, Bhatavdekar O, Howe A, Salerno D, Sempkowski M, Josefsson A, Pacheco-Torres J, Bhujwalla ZM, Gabrielson KL, Sgouros G, Sofou S. Transport-driven engineering of liposomes for delivery of α-particle radiotherapy to solid tumors: effect on inhibition of tumor progression and onset delay of spontaneous metastases. Eur J Nucl Med Mol Imaging 2021; 48:4246-4258. [PMID: 34117896 DOI: 10.1007/s00259-021-05406-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 05/10/2021] [Indexed: 12/31/2022]
Abstract
PURPOSE Highly cytotoxic α-particle radiotherapy delivered by tumor-selective nanocarriers is evaluated on metastatic Triple Negative Breast Cancer (TNBC). On vascularized tumors, the limited penetration of nanocarriers (<50-80 μm) combined with the short range of α-particles (40-100 μm) may, however, result in only partial tumor irradiation, compromising efficacy. Utilizing the α-particle emitter Actinium-225 (225Ac), we studied how the therapeutic potential of a general delivery strategy using nanometer-sized engineered liposomes was affected by two key transport-driven properties: (1) the release from liposomes, when in the tumor interstitium, of the highly diffusing 225Ac-DOTA that improves the uniformity of tumor irradiation by α-particles and (2) the adhesion of liposomes on the tumors' ECM that increases liposomes' time-integrated concentrations within tumors and, therefore, the tumor-delivered radioactivities. METHODS On an orthotopic MDA-MB-231 TNBC murine model forming spontaneous metastases, we evaluated the maximum tolerated dose (MTD), biodistributions, and control of tumor growth and/or spreading after administration of 225Ac-DOTA-encapsulating liposomes, with different combinations of the two transport-driven properties. RESULTS At 83% of MTD, 225Ac-DOTA-encapsulating liposomes with both properties (1) eliminated formation of spontaneous metastases and (2) best inhibited the progression of orthotopic xenografts, compared to liposomes lacking one or both properties. These findings were primarily affected by the extent of uniformity of the intratumoral microdistributions of 225Ac followed by the overall tumor uptake of radioactivity. At the MTD, long-term toxicities were not detected 9.5 months post administration. CONCLUSION Our findings demonstrate the potential of a general, transport-driven strategy enabling more uniform and prolonged solid tumor irradiation by α-particles without cell-specific targeting.
Collapse
Affiliation(s)
- Aprameya Prasad
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Rajiv Nair
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Omkar Bhatavdekar
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Alaina Howe
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Dominick Salerno
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | | | - Anders Josefsson
- The Russell H. Morgan Department of Radiology and Radiological Science, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jesus Pacheco-Torres
- The Russell H. Morgan Department of Radiology and Radiological Science, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Zaver M Bhujwalla
- The Russell H. Morgan Department of Radiology and Radiological Science, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Kathleen L Gabrielson
- Molecular and Comparative Pathobiology, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - George Sgouros
- The Russell H. Morgan Department of Radiology and Radiological Science, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Stavroula Sofou
- Chemical and Biomolecular Engineering (ChemBE), Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA. .,Sidney Kimmel Comprehensive Cancer Center, Cancer Invasion & Metastasis Program, Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA. .,ChemBE, Johns Hopkins University, 3400 North Charles Street, Maryland Hall 221, Baltimore, MD, 21218, USA.
| |
Collapse
|
4
|
Suman SK, Subramanian S, Mukherjee A. Combination radionuclide therapy: A new paradigm. Nucl Med Biol 2021; 98-99:40-58. [PMID: 34029984 DOI: 10.1016/j.nucmedbio.2021.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 04/23/2021] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
Targeted molecular radionuclide therapy (MRT) has shown its potential for the treatment of cancers of multiple origins. A combination therapy strategy employing two or more distinct therapeutic approaches in cancer management is aimed at circumventing tumor resistance by simultaneously targeting compensatory signaling pathways or bypassing survival selection mutations acquired in response to individual monotherapies. Combination radionuclide therapy (CRT) is a newer application of the concept, utilizing a combination of radiolabeled molecular targeting agents with chemotherapy and beam radiation therapy for enhanced therapeutic index. Encouraging results are reported with chemotherapeutic agents in combination with radiolabeled targeting molecules for cancer therapy. With increasing awareness of the various survival and stress response pathways activated after radionuclide therapy, different holistic combinations of MRT agents with radiosensitizers targeting such pathways have also been explored. MRT has also been studied in combination with beam radiotherapy modalities such as external beam radiation therapy and carbon ion radiation therapy to enhance the anti-tumor response. Nanotechnology aids in CRT by bringing together multiple monotherapies on a single nanostructure platform for treating cancers in a more precise or personalized way. CRT will be a key player in managing cancers if correctly tailored to the individual patient profile. The success of CRT lies in an in-depth understanding of the radiobiological principles and pathways activated in response.
Collapse
Affiliation(s)
- Shishu Kant Suman
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre; Homi Bhabha National Institute, Mumbai 400094, India
| | - Suresh Subramanian
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre; Homi Bhabha National Institute, Mumbai 400094, India
| | - Archana Mukherjee
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre; Homi Bhabha National Institute, Mumbai 400094, India.
| |
Collapse
|
5
|
Ahenkorah S, Cassells I, Deroose CM, Cardinaels T, Burgoyne AR, Bormans G, Ooms M, Cleeren F. Bismuth-213 for Targeted Radionuclide Therapy: From Atom to Bedside. Pharmaceutics 2021; 13:599. [PMID: 33919391 PMCID: PMC8143329 DOI: 10.3390/pharmaceutics13050599] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/14/2021] [Accepted: 04/17/2021] [Indexed: 12/17/2022] Open
Abstract
In contrast to external high energy photon or proton therapy, targeted radionuclide therapy (TRNT) is a systemic cancer treatment allowing targeted irradiation of a primary tumor and all its metastases, resulting in less collateral damage to normal tissues. The α-emitting radionuclide bismuth-213 (213Bi) has interesting properties and can be considered as a magic bullet for TRNT. The benefits and drawbacks of targeted alpha therapy with 213Bi are discussed in this review, covering the entire chain from radionuclide production to bedside. First, the radionuclide properties and production of 225Ac and its daughter 213Bi are discussed, followed by the fundamental chemical properties of bismuth. Next, an overview of available acyclic and macrocyclic bifunctional chelators for bismuth and general considerations for designing a 213Bi-radiopharmaceutical are provided. Finally, we provide an overview of preclinical and clinical studies involving 213Bi-radiopharmaceuticals, as well as the future perspectives of this promising cancer treatment option.
Collapse
Affiliation(s)
- Stephen Ahenkorah
- Institute for Nuclear Materials Science, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium; (S.A.); (I.C.); (T.C.); (A.R.B.)
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, 3000 Leuven, Belgium;
| | - Irwin Cassells
- Institute for Nuclear Materials Science, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium; (S.A.); (I.C.); (T.C.); (A.R.B.)
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, 3000 Leuven, Belgium;
| | - Christophe M. Deroose
- Nuclear Medicine Unit, University Hospitals Leuven, 3000 Leuven, Belgium;
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, University of Leuven, 3000 Leuven, Belgium
| | - Thomas Cardinaels
- Institute for Nuclear Materials Science, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium; (S.A.); (I.C.); (T.C.); (A.R.B.)
- Department of Chemistry, University of Leuven, 3001 Leuven, Belgium
| | - Andrew R. Burgoyne
- Institute for Nuclear Materials Science, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium; (S.A.); (I.C.); (T.C.); (A.R.B.)
| | - Guy Bormans
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, 3000 Leuven, Belgium;
| | - Maarten Ooms
- Institute for Nuclear Materials Science, Belgian Nuclear Research Center (SCK CEN), 2400 Mol, Belgium; (S.A.); (I.C.); (T.C.); (A.R.B.)
| | - Frederik Cleeren
- Radiopharmaceutical Research, Department of Pharmacy and Pharmacology, University of Leuven, 3000 Leuven, Belgium;
| |
Collapse
|
6
|
Rosenkranz AA, Slastnikova TA. Epidermal Growth Factor Receptor: Key to Selective Intracellular Delivery. BIOCHEMISTRY (MOSCOW) 2021; 85:967-1092. [PMID: 33050847 DOI: 10.1134/s0006297920090011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Epidermal growth factor receptor (EGFR) is an integral surface protein mediating cellular response to a number of growth factors. Its overexpression and increased activation due to mutations is one of the most common traits of many types of cancer. Development and clinical use of the agents, which block EGFR activation, became a prime example of the personalized targeted medicine. However, despite the obvious success in this area, cancer cure remains unattainable in most cases. Because of that, as well as the result of the search for possible ways to overcome the difficulties of treatment, a huge number of new treatment methods relying on the use of EGFR overexpression and its changes to destroy cancer cells. Modern data on the structure, functioning, and intracellular transport of EGFR, its natural ligands, as well as signaling cascades triggered by the EGFR activation, peculiarities of the EGFR expression and activation in oncological disorders, as well as applied therapeutic approaches aimed at blocking EGFR signaling pathway are summarized and analyzed in this review. Approaches to the targeted delivery of various chemotherapeutic agents, radionuclides, immunotoxins, photosensitizers, as well as the prospects for gene therapy aimed at cancer cells with EGFR overexpression are reviewed in detail. It should be noted that increasing attention is being paid nowadays to the development of multifunctional systems, either carrying several different active agents, or possessing several environment-dependent transport functions. Potentials of the systems based on receptor-mediated endocytosis of EGFR and their possible advantages and limitations are discussed.
Collapse
Affiliation(s)
- A A Rosenkranz
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia. .,Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - T A Slastnikova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| |
Collapse
|
7
|
Chan TG, O'Neill E, Habjan C, Cornelissen B. Combination Strategies to Improve Targeted Radionuclide Therapy. J Nucl Med 2020; 61:1544-1552. [PMID: 33037092 PMCID: PMC8679619 DOI: 10.2967/jnumed.120.248062] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 09/09/2020] [Indexed: 01/20/2023] Open
Abstract
In recent years, targeted radionuclide therapy (TRT) has emerged as a promising strategy for cancer treatment. In contrast to conventional radiotherapy, TRT delivers ionizing radiation to tumors in a targeted manner, reducing the dose that healthy tissues are exposed to. Existing TRT strategies include the use of 177Lu-DOTATATE, 131I-metaiodobenzylguanidine, Bexxar, and Zevalin, clinically approved agents for the treatment of neuroendocrine tumors, neuroblastoma, and non-Hodgkin lymphoma, respectively. Although promising results have been obtained with these agents, clinical evidence acquired to date suggests that only a small percentage of patients achieves complete response. Consequently, there have been attempts to improve TRT outcomes through combinations with other therapeutic agents; such strategies include administering concurrent TRT and chemotherapy, and the use of TRT with known or putative radiosensitizers such as poly(adenosine diphosphate ribose) polymerase and mammalian-target-of-rapamycin inhibitors. In addition to potentially achieving greater therapeutic effects than the respective monotherapies, these strategies may lead to lower dosages or numbers of cycles required and, in turn, reduce unwanted toxicities. As of now, several clinical trials have been conducted to assess the benefits of TRT-based combination therapies, sometimes despite limited preclinical evidence being available in the public domain to support their use. Although some clinical trials have yielded promising results, others have shown no clear survival benefit from particular combination treatments. Here, we present a comprehensive review of combination strategies with TRT reported in the literature to date and evaluate their therapeutic potential.
Collapse
Affiliation(s)
- Tiffany G Chan
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Edward O'Neill
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Christine Habjan
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
8
|
St James S, Bednarz B, Benedict S, Buchsbaum JC, Dewaraja Y, Frey E, Hobbs R, Grudzinski J, Roncali E, Sgouros G, Capala J, Xiao Y. Current Status of Radiopharmaceutical Therapy. Int J Radiat Oncol Biol Phys 2020; 109:891-901. [PMID: 32805300 DOI: 10.1016/j.ijrobp.2020.08.035] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 08/06/2020] [Indexed: 02/02/2023]
Abstract
In radiopharmaceutical therapy (RPT), a radionuclide is systemically or locally delivered with the goal of targeting and delivering radiation to cancer cells while minimizing radiation exposure to untargeted cells. Examples of current RPTs include thyroid ablation with the administration of 131I, treatment of liver cancer with 90Y microspheres, the treatment of bony metastases with 223Ra, and the treatment of neuroendocrine tumors with 177Lu-DOTATATE. New RPTs are being developed where radionuclides are incorporated into systemic targeted therapies. To assure that RPT is appropriately implemented, advances in targeting need to be matched with advances in quantitative imaging and dosimetry methods. Currently, radiopharmaceutical therapy is administered by intravenous or locoregional injection, and the treatment planning has typically been implemented like chemotherapy, where the activity administered is either fixed or based on a patient's body weight or body surface area. RPT pharmacokinetics are measurable by quantitative imaging and are known to vary across patients, both in tumors and normal tissues. Therefore, fixed or weight-based activity prescriptions are not currently optimized to deliver a cytotoxic dose to targets while remaining within the tolerance dose of organs at risk. Methods that provide dose estimates to individual patients rather than to reference geometries are needed to assess and adjust the injected RPT dose. Accurate doses to targets and organs at risk will benefit the individual patients and decrease uncertainties in clinical trials. Imaging can be used to measure activity distribution in vivo, and this information can be used to determine patient-specific treatment plans where the dose to the targets and organs at risk can be calculated. The development and adoption of imaging-based dosimetry methods is particularly beneficial in early clinical trials. In this work we discuss dosimetric accuracy needs in modern radiation oncology, uncertainties in the dosimetry in RPT, and best approaches for imaging and dosimetry of internal radionuclide therapy.
Collapse
Affiliation(s)
- Sara St James
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California.
| | - Bryan Bednarz
- Department of Medical Physics and Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Stanley Benedict
- Department of Radiation Oncology, University of California Davis, Sacramento, California
| | - Jeffrey C Buchsbaum
- Radiation Research Program, Division of Cancer Treatment and Diagnosis, NCI, NIH, Bethesda, Maryland
| | - Yuni Dewaraja
- Department of Radiology, University of Michigan, Ann Arbor, Michigan
| | - Eric Frey
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland
| | - Robert Hobbs
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland
| | | | - Emilie Roncali
- Department of Radiation Oncology, University of California Davis, Sacramento, California
| | - George Sgouros
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland
| | - Jacek Capala
- Radiation Research Program, Division of Cancer Treatment and Diagnosis, NCI, NIH, Bethesda, Maryland
| | - Ying Xiao
- Hospital of the University of Pennsylvania
| |
Collapse
|
9
|
Sgouros G. α-Particle-Emitter Radiopharmaceutical Therapy: Resistance Is Futile. Cancer Res 2020; 79:5479-5481. [PMID: 31676677 DOI: 10.1158/0008-5472.can-19-2806] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 11/16/2022]
Abstract
Alpha-emitter radiopharmaceutical therapy (α-RPT) is a treatment modality that is impervious to conventional cellular resistance mechanisms because of the unique properties of the α-particle. Radiobiological studies of α-particle emitters have been few as they require detailed consideration of both biology and physics. Clinical studies of this radiation delivery modality have shown highly promising results in cancers that are resistant to other treatments. The work by Yard and colleagues published in this issue introduces an innovative approach to radiobiological investigations of α-RPT and highlights the specific physics considerations required to properly investigate this multidisciplinary treatment modality.See related article by Yard et al., p. 5640.
Collapse
Affiliation(s)
- George Sgouros
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| |
Collapse
|
10
|
Schmeiser HH, Muehlbauer KR, Mier W, Baranski AC, Neels O, Dimitrakopoulou-Strauss A, Schmezer P, Kratochwil C, Bruchertseifer F, Morgenstern A, Kopka K. DNA damage in human whole blood caused by radiopharmaceuticals evaluated by the comet assay. Mutagenesis 2020; 34:239-244. [PMID: 31107537 PMCID: PMC6753384 DOI: 10.1093/mutage/gez007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/20/2019] [Accepted: 03/20/2019] [Indexed: 11/24/2022] Open
Abstract
Radiopharmaceuticals used for diagnosis or therapy induce DNA strand breaks, which may be detectable by single-cell gel electrophoresis (called comet assay). Blood was taken from patients before and at different time points after treatment with radiopharmaceuticals; blood cells were investigated by the comet assay using the percentage of DNA in the tail as the critical parameter. Whereas [225Ac]Ac-prostate-specific membrane antigen (PSMA)-617 alpha therapy showed no difference relative to the blood sample taken before treatment, beta therapy with [177Lu]Lu-PSMA-617 3 h post-injection revealed a small but significant increase in DNA strand breaks. In blood of patients who underwent positron emission tomography (PET) with either [18F]2-fluor-2-deoxy-D-glucose (FDG) or [68Ga]Ga-PSMA-11, an increase of DNA migration determined by the comet assay was not found when analysed at different time points (2–70 min) after intravenous tracer injection. Human whole blood was incubated with the targeted clinically relevant therapeutic radiopharmaceuticals [225Ac]Ac-PSMA-617, [177Lu]Lu-PSMA-617 and [90Y]Y-DOTA(0)-Phe(1)-Tyr(3)-octreotide (DOTA-TOC) at different activity concentrations (kBq/ml) for 5 days and then analysed by the comet assay. DNA damage increased with higher concentrations of all radiolabeled compounds tested. [177Lu]Lu-PSMA-617 caused higher blood cell radiotoxicity than equal activity concentrations of [90Y]Y-DOTA-TOC. Likewise, whole human blood was exposed to the positron emitters [18F]FDG and [68Ga]Ga-PSMA-11 in vitro for 24 h with activity concentrations ranging between 5 and 40 MBq/ml. The same activity concentration dependent elevated DNA migration was observed for both compounds although decay energies are different. This study demonstrated that the amount of DNA damage detected by the comet assay in whole human blood is similar among different positron emitters and divergent by a factor of 200 between alpha particles and beta radiation.
Collapse
Affiliation(s)
- Heinz H Schmeiser
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld, Heidelberg, Germany
| | - Karl-Rudolf Muehlbauer
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld, Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg, Germany
| | - Ann-Christin Baranski
- Division of Radiopharmaceutical Development, German Cancer Consortium (DKTK), Partner Site Freiburg, and Department of Nuclear Medicine, University Medical Center, Hugstetter Straße, Freiburg, Germany
| | - Oliver Neels
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld, Heidelberg, Germany.,Division of Radiopharmaceutical Chemistry, German Cancer Consortium (DKTK), Im Neuenheimer FeldHeidelberg, Germany
| | | | - Peter Schmezer
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Im Neuenheimer Feld Heidelberg, Germany
| | - Clemens Kratochwil
- Department of Nuclear Medicine, University Hospital Heidelberg, Im Neuenheimer Feld, Heidelberg, Germany
| | - Frank Bruchertseifer
- European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Karlsruhe, Germany
| | - Alfred Morgenstern
- European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Karlsruhe, Germany
| | - Klaus Kopka
- Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld, Heidelberg, Germany.,Division of Radiopharmaceutical Chemistry, German Cancer Consortium (DKTK), Im Neuenheimer FeldHeidelberg, Germany
| |
Collapse
|
11
|
Sgouros G. Dosimetry, Radiobiology and Synthetic Lethality: Radiopharmaceutical Therapy (RPT) With Alpha-Particle-Emitters. Semin Nucl Med 2020; 50:124-132. [PMID: 32172797 DOI: 10.1053/j.semnuclmed.2019.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
As a treatment modality that is fundamentally different from other therapies against cancer, radiopharmaceutical therapy with alpha-particle emitters has drawn the attention of the therapy community and also the biopharmaceutical industry. Alpha-particles cause a preponderance of complex DNA double-strand breaks (DSBs). This provides an opportunity to either enhance cell kill by using DNA DSB repair inhibitors or identify patients who are likely to be high responders to alpha-emitter RPT. The short-range and high potency of alpha-particles requires special dosimetry considerations. These are reviewed in light of recent updates to the phantoms and associated dosimetric quantities used for dosimetry calculations. A formalism for obtaining the necessary microscale pharmacokinetic information from patient nuclear medicine imaging is presented. Alpha-emitter based radiopharmaceutical therapy is an exciting cancer therapy modality that is being revisited. Further development of imaging and dosimetric methods specific to alpha-particle emitters, coupled with standardization of the methods and rigorous evidence that dosimetry applied to alphaRPT improves patient care are needed moving forward.
Collapse
Affiliation(s)
- George Sgouros
- Radiological Physics Division, Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, MD.
| |
Collapse
|
12
|
Preclinical Combination Studies of an FGFR2 Targeted Thorium-227 Conjugate and the ATR Inhibitor BAY 1895344. Int J Radiat Oncol Biol Phys 2019; 105:410-422. [DOI: 10.1016/j.ijrobp.2019.06.2508] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/10/2019] [Accepted: 06/01/2019] [Indexed: 11/23/2022]
|
13
|
Sgouros G. The Case for Dosimetry in Alpha-Emitter Therapy. J Med Imaging Radiat Sci 2019; 50:S45-S46. [PMID: 31537496 DOI: 10.1016/j.jmir.2019.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/13/2019] [Accepted: 07/17/2019] [Indexed: 10/26/2022]
Abstract
Despite ongoing efforts with new chemotherapeutics, small-molecule inhibitors and biologics, patients with distant metastases continue to have a grim prognosis. Radiopharmaceutical therapy (RPT) with alpha-particle-emitting radionuclides has shown efficacy against widespread disease. Alpha-particle emitters are particularly effective because their short range and high energy deposit density lead to complex and largely irreparable DNA double-strand breaks. The high potency against tumors can also lead to high toxicity. Unlike most systemic treatment of cancer, the biodistribution of RPT agents may be imaged in humans using nuclear medicine imaging modalities. In this context, dosimetry provides a precision medicine approach to implementing RPT with alpha-emitters.
Collapse
Affiliation(s)
- George Sgouros
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
14
|
Yard BD, Gopal P, Bannik K, Siemeister G, Hagemann UB, Abazeed ME. Cellular and Genetic Determinants of the Sensitivity of Cancer to α-Particle Irradiation. Cancer Res 2019; 79:5640-5651. [PMID: 31387923 DOI: 10.1158/0008-5472.can-19-0859] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 06/12/2019] [Accepted: 07/29/2019] [Indexed: 12/20/2022]
Abstract
Targeted α-particle-emitting radionuclides have great potential for the treatment of a broad range of cancers at different stages of progression. A platform that accurately measures cancer cellular sensitivity to α-particle irradiation could guide and accelerate clinical translation. Here, we performed high-content profiling of cellular survival following exposure to α-particles emitted from radium-223 (223Ra) using 28 genetically diverse human tumor cell lines. Significant variation in cellular sensitivity across tumor cells was observed. 223Ra was significantly more potent than sparsely ionizing irradiation, with a median relative biological effectiveness of 10.4 (IQR: 8.4-14.3). Cells that are the most resistant to γ radiation, such as Nrf2 gain-of-function mutant cells, were sensitive to α-particles. Combining these profiling results with genetic features, we identified several somatic copy-number alterations, gene mutations, and the basal expression of gene sets that correlated with radiation survival. Activating mutations in PIK3CA, a frequent event in cancer, decreased sensitivity to 223Ra. The identification of cellular and genetic determinants of sensitivity to 223Ra may guide the clinical incorporation of targeted α-particle emitters in the treatment of several cancer types. SIGNIFICANCE: These findings address limitations in the preclinical guidance and prediction of radionuclide tumor sensitivity by identifying intrinsic cellular and genetic determinants of cancer cell survival following exposure to α-particle irradiation.See related commentary by Sgouros, p. 5479.
Collapse
Affiliation(s)
- Brian D Yard
- Department of Translational Hematology Oncology Research, Cleveland Clinic, Cleveland, Ohio
| | - Priyanka Gopal
- Department of Translational Hematology Oncology Research, Cleveland Clinic, Cleveland, Ohio
| | - Kristina Bannik
- Research and Development, Pharmaceuticals, Bayer AG, Berlin, Germany
| | | | - Urs B Hagemann
- Research and Development, Pharmaceuticals, Bayer AG, Berlin, Germany
| | - Mohamed E Abazeed
- Department of Translational Hematology Oncology Research, Cleveland Clinic, Cleveland, Ohio. .,Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio
| |
Collapse
|
15
|
Ohshima Y, Kono N, Yokota Y, Watanabe S, Sasaki I, Ishioka NS, Sakashita T, Arakawa K. Anti-tumor effects and potential therapeutic response biomarkers in α-emitting meta- 211At-astato-benzylguanidine therapy for malignant pheochromocytoma explored by RNA-sequencing. Theranostics 2019; 9:1538-1549. [PMID: 31037122 PMCID: PMC6485192 DOI: 10.7150/thno.30353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/04/2019] [Indexed: 12/13/2022] Open
Abstract
Targeted α-particle therapy is a promising option for patients with malignant pheochromocytoma. Recent observations regarding meta-211At-astato-benzylguanidine (211At-MABG) in a pheochromocytoma mouse model showed a strong anti-tumor effect, though the molecular mechanism remains elusive. Here, we present the first comprehensive RNA-sequencing (RNA-seq) data for pheochromocytoma cells based on in vitro211At-MABG administration experiments. Key genes and pathways in the tumor α-particle radiation response are also examined to obtain potential response biomarkers. Methods: We evaluated genome-wide transcriptional alterations in the rat pheochromocytoma cell line PC12 at 3, 6, and 12 h after 211At-MABG treatment; a control experiment using 60Co γ-ray irradiation was carried out to highlight 211At-MABG-specific gene expression. For comparisons, 10% and 80% iso-survival doses (0.8 and 0.1 kBq/mL for 211At-MABG and 10 and 1 Gy for 60Co γ-rays) were used. Results: Enrichment analysis of differentially expressed genes (DEGs) and analysis of the gene expression profiles of cell cycle checkpoints revealed similar modes of cell death via the p53-p21 signaling pathway after 211At-MABG treatment and γ-ray irradiation. The top list of ranked DEGs demonstrated the expression of key genes on the decrease in the survival following 211At-MABG exposure, and four potential genes (Mien1, Otub1, Vdac1 and Vegfa genes) of 211At-MABG therapy. Western blot analysis indicated increased expression of TSPO in 211At-MABG-treated cells, suggesting its potential as a PET imaging probe. Conclusion: Comprehensive RNA-seq revealed contrasting cellular responses to γ-ray and α-particle therapy, leading to the identification of four potential candidate genes that may serve as molecular imaging and 211At-MABG therapy targets.
Collapse
|
16
|
Abstract
α-Particle irradiation of cancerous tissue is increasingly recognized as a potent therapeutic option. We briefly review the physics, radiobiology, and dosimetry of α-particle emitters, as well as the distinguishing features that make them unique for radiopharmaceutical therapy. We also review the emerging clinical role of α-particle therapy in managing cancer and recent studies on in vitro and preclinical α-particle therapy delivered by antibodies, other small molecules, and nanometer-sized particles. In addition to their unique radiopharmaceutical characteristics, the increased availability and improved radiochemistry of α-particle radionuclides have contributed to the growing recent interest in α-particle radiotherapy. Targeted therapy strategies have presented novel possibilities for the use of α-particles in the treatment of cancer. Clinical experience has already demonstrated the safe and effective use of α-particle emitters as potent tumor-selective drugs for the treatment of leukemia and metastatic disease.
Collapse
Affiliation(s)
- Michael R McDevitt
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Department of Radiology, Weill Cornell Medical College, New York, NY 10065, USA
| | - George Sgouros
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Stavroula Sofou
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| |
Collapse
|
17
|
Kasten BB, Oliver PG, Kim H, Fan J, Ferrone S, Zinn KR, Buchsbaum DJ. 212Pb-Labeled Antibody 225.28 Targeted to Chondroitin Sulfate Proteoglycan 4 for Triple-Negative Breast Cancer Therapy in Mouse Models. Int J Mol Sci 2018; 19:ijms19040925. [PMID: 29561763 PMCID: PMC5979285 DOI: 10.3390/ijms19040925] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 01/16/2023] Open
Abstract
Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis. There is a clinical need for effective, targeted therapy strategies that destroy both differentiated TNBC cells and TNBC cancer initiating cells (CICs), as the latter are implicated in the metastasis and recurrence of TNBC. Chondroitin sulfate proteoglycan 4 (CSPG4) is overexpressed on differentiated tumor cells and CICs obtained from TNBC patient specimens, suggesting that CSPG4 may be a clinically relevant target for the imaging and therapy of TNBC. The purpose of this study was to determine whether α-particle radioimmunotherapy (RIT) targeting TNBC cells using the CSPG4-specific monoclonal antibody (mAb) 225.28 as a carrier was effective at eliminating TNBC tumors in preclinical models. To this end, mAb 225.28 labeled with 212Pb (212Pb-225.28) as a source of α-particles for RIT was used for in vitro Scatchard assays and clonogenic survival assays with human TNBC cells (SUM159 and 2LMP) grown as adherent cells or non-adherent CIC-enriched mammospheres. Immune-deficient mice bearing orthotopic SUM159 or 2LMP xenografts were injected i.v. with the targeted (225.28) or irrelevant isotype-matched control (F3-C25) mAbs, labeled with 99mTc, 125I, or 212Pb for in vivo imaging, biodistribution, or tumor growth inhibition studies. 212Pb-225.28 bound to adherent SUM159 and 2LMP cells and to CICs from SUM159 and 2LMP mammospheres with a mean affinity of 0.5 nM. Nearly ten times more binding sites per cell were present on SUM159 cells and CICs compared with 2LMP cells. 212Pb-225.28 was six to seven times more effective than 212Pb-F3-C25 at inhibiting SUM159 cell and CIC clonogenic survival (p < 0.05). Radiolabeled mAb 225.28 showed significantly higher uptake than radiolabeled mAb F3-C25 in SUM159 and 2LMP xenografts (p < 0.05), and the uptake of 212Pb-225.28 in TNBC xenografts was correlated with target epitope expression. 212Pb-225.28 caused dose-dependent growth inhibition of SUM159 xenografts; 0.30 MBq 212Pb-225.28 was significantly more effective than 0.33 MBq 212Pb-F3-C25 at inhibiting tumor growth (p < 0.01). These results suggest that CSPG4-specific 212Pb-225.28 is a useful reagent for RIT of CSPG4-expressing tumors, including metastatic TNBC.
Collapse
Affiliation(s)
- Benjamin B Kasten
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Patsy G Oliver
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Harrison Kim
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Jinda Fan
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Kurt R Zinn
- Institute for Quantitative Health Science and Engineering, Department of Radiology, Michigan State University, East Lansing, MI 48824, USA.
| | - Donald J Buchsbaum
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| |
Collapse
|
18
|
Chalakur-Ramireddy NKR, Pakala SB. Combined drug therapeutic strategies for the effective treatment of Triple Negative Breast Cancer. Biosci Rep 2018; 38:BSR20171357. [PMID: 29298879 PMCID: PMC5789156 DOI: 10.1042/bsr20171357] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/12/2017] [Accepted: 01/01/2018] [Indexed: 12/19/2022] Open
Abstract
TNBC (Triple Negative Breast Cancer) is a subtype of breast cancer with an aggressive phenotype which shows high metastatic capability and poor prognosis. Owing to its intrinsic properties like heterogeneity, lack of hormonal receptors and aggressive phenotype leave chemotherapy as a mainstay for the treatment of TNBC. Various studies have demonstrated that chemotherapy alone or therapeutic drugs targeting TNBC pathways, epigenetic mechanisms and immunotherapy alone have not shown significant improvement in TNBC patients. On the other hand, a combination of therapeutic drugs or addition of chemotherapy with therapeutic drugs has shown substantial improvement in results and proven to be an effective strategy for TNBC treatment. This review sheds light on effective combinational drug strategies and current clinical trial status of various combinatorial drugs for the treatment of TNBC.
Collapse
Affiliation(s)
| | - Suresh B Pakala
- Biology Division, Indian Institute of Science Education and Research (IISER) Tirupati, Andhra Pradesh, India
| |
Collapse
|
19
|
Banisadr A, Safdari Y, Kianmehr A, Pourafshar M. Production of a germline-humanized cetuximab scFv and evaluation of its activity in recognizing EGFR- overexpressing cancer cells. Hum Vaccin Immunother 2017; 14:856-863. [PMID: 29185855 DOI: 10.1080/21645515.2017.1407482] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The aim of this study was to produce a humanized single chain antibody (scFv) as a potential improved product design to target EGFR (Epidermal Growth Factor Receptor) overexpressing cancer cells. To this end, CDR loops of cetuximab (an FDA-approved anti-EGFR antibody) were grafted on framework regions derived from type 3 (VH3 and VL3 kappa) human germline sequences to obtain recombinant VH and VL domainslinked together with a flexible linker [(Gly4Ser)3] to form a scFv. Codon optimized synthetic gene encoding the scFv (with NH2-VH-linker-VL-COOH orientation) was expressed in E. coli Origami™ 2(DE3) cells and the resultant scFv purified by using Ni-NTA affinity chromatography. The scFv, called cet.Hum scFv, was evaluated in ELISA and immunoblot to determine whether it can recognize EGFR. The scFv was able to recognize EGFR over-expressing cancer cells (A-431) but failed to detect cancer cells with low levels of EGFR (MCF-7 cells). Although the affinity of the scFv forA-431 cells was 9 fold lower than that of cetuximab, it was strong enough to recognize these cells. Considering its ability to bind EGFR molecules, the scFv may exhibit a potential application for the detection of EGFR-overexpressing cancer cells.
Collapse
Affiliation(s)
- Arsham Banisadr
- a Department of Medical Biotechnology , School of Advanced Technologies in Medicine, Golestan University of Medical Sciences , Gorgan , Iran
| | - Yaghoub Safdari
- b Golestan Research Center of Gastroenterology & Hepatology (GRCGH), Golestan University of Medical Sciences , Gorgan , Iran
| | - Anvarsadat Kianmehr
- c Cancer Research Center, Golestan University of Medical Sciences , Gorgan , Iran
| | - Mahdieh Pourafshar
- a Department of Medical Biotechnology , School of Advanced Technologies in Medicine, Golestan University of Medical Sciences , Gorgan , Iran
| |
Collapse
|
20
|
Chan HS, de Blois E, Morgenstern A, Bruchertseifer F, de Jong M, Breeman W, Konijnenberg M. In Vitro comparison of 213Bi- and 177Lu-radiation for peptide receptor radionuclide therapy. PLoS One 2017; 12:e0181473. [PMID: 28732021 PMCID: PMC5521788 DOI: 10.1371/journal.pone.0181473] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/30/2017] [Indexed: 01/15/2023] Open
Abstract
Background Absorbed doses for α-emitters are different from those for β-emitters, as the high linear energy transfer (LET) nature of α-particles results in a very dense energy deposition over a relatively short path length near the point of emission. This highly localized and therefore high energy deposition can lead to enhanced cell-killing effects at absorbed doses that are non-lethal in low-LET type of exposure. Affinities of DOTA-DPhe1-Tyr3-octreotate (DOTATATE), 115In-DOTATATE, 175Lu-DOTATATE and 209Bi-DOTATATE were determined in the K562-SST2 cell line. Two other cell lines were used for radiation response assessment; BON and CA20948, with a low and high expression of somatostatin receptors, respectively. Cellular uptake kinetics of 111In-DOTATATE were determined in CA20948 cells. CA20948 and BON were irradiated with 137Cs, 177Lu-DTPA, 177Lu-DOTATATE, 213Bi-DTPA and 213Bi-DOTATATE. Absorbed doses were calculated using the MIRDcell dosimetry method for the specific binding and a Monte Carlo model of a cylindrical 6-well plate geometry for the exposure by the radioactive incubation medium. Absorbed doses were compared to conventional irradiation of cells with 137Cs and the relative biological effect (RBE) at 10% survival was calculated. Results IC50 of (labelled) DOTATATE was in the nM range. Absorbed doses up to 7 Gy were obtained by 5.2 MBq 213Bi-DOTATATE, in majority the dose was caused by α-particle radiation. Cellular internalization determined with 111In-DOTATATE showed a linear relation with incubation time. Cell survival after exposure of 213Bi-DTPA and 213Bi-DOTATATE to BON or CA20948 cells showed a linear-exponential relation with the absorbed dose, confirming the high LET character of 213Bi. The survival of CA20948 after exposure to 177Lu-DOTATATE and the reference 137Cs irradiation showed the typical curvature of the linear-quadratic model. 10% Cell survival of CA20948 was reached at 3 Gy with 213Bi-DOTATATE, a factor 6 lower than the 18 Gy found for 177Lu-DOTATATE and also below the 5 Gy after 137Cs external exposure. Conclusion 213Bi-DTPA and 213Bi-DOTATATE lead to a factor 6 advantage in cell killing compared to 177Lu-DOTATATE. The RBE at 10% survival by 213Bi-ligand compared to 137Cs was 2.0 whereas the RBE for 177Lu-DOTATATE was 0.3 in the CA20948 in vitro model.
Collapse
Affiliation(s)
- Ho Sze Chan
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- * E-mail:
| | - Erik de Blois
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Alfred Morgenstern
- European Commission, Joint Research Centre, Institute for Transuranium Elements (ITU), Karlsruhe, Germany
| | - Frank Bruchertseifer
- European Commission, Joint Research Centre, Institute for Transuranium Elements (ITU), Karlsruhe, Germany
| | - Marion de Jong
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Wouter Breeman
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Mark Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| |
Collapse
|
21
|
Norton KA, Wallace T, Pandey NB, Popel AS. An agent-based model of triple-negative breast cancer: the interplay between chemokine receptor CCR5 expression, cancer stem cells, and hypoxia. BMC SYSTEMS BIOLOGY 2017; 11:68. [PMID: 28693495 PMCID: PMC5504656 DOI: 10.1186/s12918-017-0445-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 06/30/2017] [Indexed: 12/19/2022]
Abstract
Background Triple-negative breast cancer lacks estrogen, progesterone, and HER2 receptors and is thus not possible to treat with targeted therapies for these receptors. Therefore, a greater understanding of triple-negative breast cancer is necessary for the treatment of this cancer type. In previous work from our laboratory, we found that chemokine ligand-receptor CCL5-CCR5 axis is important for the metastasis of human triple-negative breast cancer cell MDA-MB-231 to the lymph nodes and lungs, in a mouse xenograft model. We collected relevant experimental data from our and other laboratories for numbers of cancer stem cells, numbers of CCR5+ cells, and cell migration rates for different breast cancer cell lines and different experimental conditions. Results Using these experimental data we developed an in silico agent-based model of triple-negative breast cancer that considers surface receptor CCR5-high and CCR5-low cells and breast cancer stem cells, to predict the tumor growth rate and spatio-temporal distribution of cells in primary tumors. We find that high cancer stem cell percentages greatly increase tumor growth. We find that anti-stem cell treatment decreases tumor growth but may not lead to dormancy unless all stem cells get eliminated. We further find that hypoxia increases overall tumor growth and treatment with a CCR5 inhibitor maraviroc slightly decreases overall tumor growth. We also characterize 3D shapes of solid and invasive tumors using several shape metrics. Conclusions Breast cancer stem cells and CCR5+ cells affect the overall growth and morphology of breast tumors. In silico drug treatments demonstrate limited efficacy of incomplete inhibition of cancer stem cells after which tumor growth recurs, and CCR5 inhibition causes only a slight reduction in tumor growth. Electronic supplementary material The online version of this article (doi:10.1186/s12918-017-0445-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kerri-Ann Norton
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.
| | - Travis Wallace
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Niranjan B Pandey
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Aleksander S Popel
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Oncology and the Sidney Kimmel Comprehensive Cancer Center, School of Medicine, Johns Hopkins University, Baltimore, USA
| |
Collapse
|
22
|
Targeted α-Particle Radiation Therapy of HER1-Positive Disseminated Intraperitoneal Disease: An Investigation of the Human Anti-EGFR Monoclonal Antibody, Panitumumab. Transl Oncol 2017; 10:535-545. [PMID: 28577439 PMCID: PMC5458064 DOI: 10.1016/j.tranon.2017.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/13/2017] [Accepted: 04/17/2017] [Indexed: 11/29/2022] Open
Abstract
Identifying molecular targets and an appropriate targeting vehicle, i.e., monoclonal antibodies (mAb) and their various forms, for radioimmunotherapy (RIT) remains an active area of research. Panitumumab, a fully human and less immunogenic mAb that binds to the epidermal growth factor receptor (Erb1; HER1), was evaluated for targeted α-particle radiation therapy using 212Pb, an in vivo α generator. A single dose of 212Pb-panitumumab administered to athymic mice bearing LS-174T intraperitoneal (i.p.) tumor xenografts was found to have greater therapeutic efficacy when directly compared with 212Pb-trastuzumab, which binds to HER2. A dose escalation study determined a maximum effective working dose of 212Pb-panitumumab to be 20 μCi with a median survival of 35 days versus 25 days for the untreated controls. Pretreatment of tumor-bearing mice with paclitaxel and gemcitabine 24 hours prior to injection of 212Pb-pantiumumab at 10 or 20 μCi resulted in the greatest enhanced therapeutic response at the higher dose with median survivals of 106 versus 192 days, respectively. The greatest therapeutic impact, however, was observed in the animals that were treated with topotecan 24 hours prior to RIT and then again 24 hours after RIT; the best response from this combination was also obtained with the lower 10-μCi dose of 212Pb-panitumumab (median survival >280 days). In summary, 212Pb-panitumumab is an excellent candidate for the treatment of HER1-positive disseminated i.p. disease. Furthermore, the potentiation of the therapeutic impact of 212Pb-pantiumumab by chemotherapeutics confirms and validates the importance of developing a multimodal therapy regimen.
Collapse
|
23
|
Liu Y, Yin X, Zhong J, Guan N, Luo Z, Min L, Yao X, Bo X, Dai L, Bai H. Systematic Identification and Assessment of Therapeutic Targets for Breast Cancer Based on Genome-Wide RNA Interference Transcriptomes. Genes (Basel) 2017; 8:genes8030086. [PMID: 28245581 PMCID: PMC5368690 DOI: 10.3390/genes8030086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/24/2017] [Accepted: 02/13/2017] [Indexed: 12/15/2022] Open
Abstract
With accumulating public omics data, great efforts have been made to characterize the genetic heterogeneity of breast cancer. However, identifying novel targets and selecting the best from the sizeable lists of candidate targets is still a key challenge for targeted therapy, largely owing to the lack of economical, efficient and systematic discovery and assessment to prioritize potential therapeutic targets. Here, we describe an approach that combines the computational evaluation and objective, multifaceted assessment to systematically identify and prioritize targets for biological validation and therapeutic exploration. We first establish the reference gene expression profiles from breast cancer cell line MCF7 upon genome-wide RNA interference (RNAi) of a total of 3689 genes, and the breast cancer query signatures using RNA-seq data generated from tissue samples of clinical breast cancer patients in the Cancer Genome Atlas (TCGA). Based on gene set enrichment analysis, we identified a set of 510 genes that when knocked down could significantly reverse the transcriptome of breast cancer state. We then perform multifaceted assessment to analyze the gene set to prioritize potential targets for gene therapy. We also propose drug repurposing opportunities and identify potentially druggable proteins that have been poorly explored with regard to the discovery of small-molecule modulators. Finally, we obtained a small list of candidate therapeutic targets for four major breast cancer subtypes, i.e., luminal A, luminal B, HER2+ and triple negative breast cancer. This RNAi transcriptome-based approach can be a helpful paradigm for relevant researches to identify and prioritize candidate targets for experimental validation.
Collapse
Affiliation(s)
- Yang Liu
- Research Center for Clinical & Translational Medicine, Beijing 302 Hospital, Beijing 100039, China.
| | - Xiaoyao Yin
- Science and technology on Parallel and Distributed Processing Laboratory, National University of Defense Technology, Changsha 410073, China.
| | - Jing Zhong
- Huzhou Key Laboratory of Molecular Medicine, Huzhou Central Hospital, Huzhou 313000, China.
| | - Naiyang Guan
- Science and technology on Parallel and Distributed Processing Laboratory, National University of Defense Technology, Changsha 410073, China.
| | - Zhigang Luo
- Science and technology on Parallel and Distributed Processing Laboratory, National University of Defense Technology, Changsha 410073, China.
| | - Lishan Min
- Huzhou Key Laboratory of Molecular Medicine, Huzhou Central Hospital, Huzhou 313000, China.
| | - Xing Yao
- Huzhou Key Laboratory of Molecular Medicine, Huzhou Central Hospital, Huzhou 313000, China.
| | - Xiaochen Bo
- Beijing Institute of Radiation Medicine, Beijing 100850, China.
| | - Licheng Dai
- Huzhou Key Laboratory of Molecular Medicine, Huzhou Central Hospital, Huzhou 313000, China.
| | - Hui Bai
- Beijing Institute of Radiation Medicine, Beijing 100850, China.
- No. 451 Hospital of PLA, Xi'an 710054, China.
| |
Collapse
|
24
|
Aghevlian S, Boyle AJ, Reilly RM. Radioimmunotherapy of cancer with high linear energy transfer (LET) radiation delivered by radionuclides emitting α-particles or Auger electrons. Adv Drug Deliv Rev 2017; 109:102-118. [PMID: 26705852 DOI: 10.1016/j.addr.2015.12.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/26/2015] [Accepted: 12/06/2015] [Indexed: 12/31/2022]
Abstract
Radioimmunotherapy (RIT) aims to selectively deliver radionuclides emitting α-particles, β-particles or Auger electrons to tumors by conjugation to monoclonal antibodies (mAbs) that recognize tumor-associated antigens/receptors. The approach has been most successful for treatment of non-Hodgkin's B-cell lymphoma but challenges have been encountered in extending these promising results to the treatment of solid malignancies. These challenges include the low potency of β-particle emitters such as 131I, 177Lu or 90Y which have been commonly conjugated to the mAbs, due to their low linear energy transfer (LET=0.1-1.0keV/μm). Furthermore, since the β-particles have a 2-10mm range, there has been dose-limiting non-specific toxicity to hematopoietic stem cells in the bone marrow (BM) due to the cross-fire effect. Conjugation of mAbs to α-particle-emitters (e.g. 225Ac, 213Bi, 212Pb or 211At) or Auger electron-emitters (e.g. 111In, 67Ga, 123I or 125I) would increase the potency of RIT due to their high LET (50-230keV/μm and 4 to 26keV/μm, respectively). In addition, α-particles have a range in tissues of 28-100μm and Auger electrons are nanometer in range which greatly reduces or eliminates the cross-fire effect compared to β-particles, potentially reducing their non-specific toxicity to the BM. In this review, we describe the results of preclinical and clinical studies of RIT of cancer using radioimmunoconjugates emitting α-particles or Auger electrons, and discuss the potential of these high LET forms of radiation to improve the outcome of cancer patients.
Collapse
Affiliation(s)
- Sadaf Aghevlian
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Amanda J Boyle
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
| | - Raymond M Reilly
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada; Toronto General Research Institute and Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada.
| |
Collapse
|
25
|
Chan HS, Konijnenberg MW, Daniels T, Nysus M, Makvandi M, de Blois E, Breeman WA, Atcher RW, de Jong M, Norenberg JP. Improved safety and efficacy of 213Bi-DOTATATE-targeted alpha therapy of somatostatin receptor-expressing neuroendocrine tumors in mice pre-treated with L-lysine. EJNMMI Res 2016; 6:83. [PMID: 27873240 PMCID: PMC5118228 DOI: 10.1186/s13550-016-0240-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 11/15/2016] [Indexed: 02/07/2023] Open
Abstract
Background Targeted alpha therapy (TAT) offers advantages over current β-emitting conjugates for peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors. PRRT with 177Lu-DOTATATE or 90Y-DOTATOC has shown dose-limiting nephrotoxicity due to radiopeptide retention in the proximal tubules. Pharmacological protection can reduce renal uptake of radiopeptides, e.g., positively charged amino acids, to saturate in the proximal tubules, thereby enabling higher radioactivity to be safely administered. The aim of this preclinical study was to evaluate the therapeutic effect of 213Bi-DOTATATE with and without renal protection using L-lysine in mice. Tumor uptake and kinetics as a function of injected mass of peptide (range 0.03–3 nmol) were investigated using 111In-DOTATATE. These results allowed estimation of the mean radiation absorbed tumor dose for 213Bi-DOTATATE. Pharmacokinetics and dosimetry of 213Bi-DOTATATE was determined in mice, in combination with renal protection. A dose escalation study with 213Bi-DOTATATE was performed to determine the maximum tolerated dose (MTD) with and without pre-administration of l-lysine as for renal protection. Neutrophil gelatinase-associated lipocalin (NGAL) served as renal biomarker to determine kidney injury. Results The maximum mean radiation absorbed tumor dose occurred at 0.03 nmol and the minimum at 3 nmol. Similar mean radiation absorbed tumor doses were determined for 0.1 and 0.3 nmol with a mean radiation absorbed dose of approximately 0.5 Gy/MBq 213Bi-DOTATATE. The optimal mass of injected peptide was found to be 0.3 nmol. Tumor uptake was similar for 111In-DOTATATE and 213Bi-DOTATATE at 0.3 nmol peptide. Lysine reduced the renal uptake of 213Bi-DOTATATE by 50% with no effect on the tumor uptake. The MTD was <13.0 ± 1.6 MBq in absence of l-lysine and 21.7 ± 1.9 MBq with l-lysine renal protection, both imparting an LD50 mean renal radiation absorbed dose of 20 Gy. A correlation was found between the amount of injected radioactivity and NGAL levels. Conclusions The therapeutic potential of 213Bi-DOTATATE was illustrated by significantly decreased tumor burden and improved overall survival. Renal protection with l-lysine immediately prior to TAT with 213Bi-DOTATATE prolonged survival providing substantial evidence for pharmacological nephron blockade to mitigate nephrotoxicity. Electronic supplementary material The online version of this article (doi:10.1186/s13550-016-0240-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ho Sze Chan
- Department of Radiology and Nuclear Medicine, Erasmus MC, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
| | - Mark W Konijnenberg
- Department of Radiology and Nuclear Medicine, Erasmus MC, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | - Tamara Daniels
- Radiopharmaceutical Sciences Program, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Monique Nysus
- Radiopharmaceutical Sciences Program, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Mehran Makvandi
- Radiopharmaceutical Sciences Program, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Erik de Blois
- Department of Radiology and Nuclear Medicine, Erasmus MC, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | - Wouter A Breeman
- Department of Radiology and Nuclear Medicine, Erasmus MC, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | - Robert W Atcher
- Radiopharmaceutical Sciences Program, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Marion de Jong
- Department of Radiology and Nuclear Medicine, Erasmus MC, 's Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
| | - Jeffrey P Norenberg
- Radiopharmaceutical Sciences Program, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| |
Collapse
|
26
|
Kmochova A, Tichy A, Zarybnicka L, Sinkorova Z, Vavrova J, Rehacek V, Durisova K, Kubelkova K, Pejchal J, Kuca K. Modulation of ionizing radiation-induced effects by NU7441, KU55933 and VE821 in peripheral blood lymphocytes. J Appl Biomed 2016. [DOI: 10.1016/j.jab.2015.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
27
|
Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015. [PMID: 26579492 DOI: 10.3389/fonc.2015.00240] [] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination - a repair pathway activated in response to double-strand DNA breaks (DSB) - are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
Collapse
Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| |
Collapse
|
28
|
Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015. [PMID: 26579492 DOI: 10.3389/fonc.2015.00240]+[] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination - a repair pathway activated in response to double-strand DNA breaks (DSB) - are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
Collapse
Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| |
Collapse
|
29
|
Kalimutho M, Parsons K, Mittal D, López JA, Srihari S, Khanna KK. Targeted Therapies for Triple-Negative Breast Cancer: Combating a Stubborn Disease. Trends Pharmacol Sci 2015; 36:822-846. [PMID: 26538316 DOI: 10.1016/j.tips.2015.08.009] [Citation(s) in RCA: 203] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/14/2015] [Accepted: 08/17/2015] [Indexed: 11/17/2022]
Abstract
Triple-negative breast cancers (TNBCs) constitute a heterogeneous subtype of breast cancers that have a poor clinical outcome. Although no approved targeted therapy is available for TNBCs, molecular-profiling efforts have revealed promising molecular targets, with several candidate compounds having now entered clinical trials for TNBC patients. However, initial results remain modest, thereby highlighting challenges potentially involving intra- and intertumoral heterogeneity and acquisition of therapy resistance. We present a comprehensive review on emerging targeted therapies for treating TNBCs, including the promising approach of immunotherapy and the prognostic value of tumor-infiltrating lymphocytes. We discuss the impact of pathway rewiring in the acquisition of drug resistance, and the prospect of employing combination therapy strategies to overcome challenges towards identifying clinically-viable targeted treatment options for TNBC.
Collapse
Affiliation(s)
- Murugan Kalimutho
- Signal Transduction Laboratory, Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Herston, Brisbane, QLD 4006, Australia.
| | - Kate Parsons
- Signal Transduction Laboratory, Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Herston, Brisbane, QLD 4006, Australia; School of Natural Sciences, Griffith University, Nathan, QLD 411, Australia
| | - Deepak Mittal
- Immunology in Cancer and Infection Laboratory, QIMR Berghofer Medical Research Institute, Herston, Brisbane, QLD 4006, Australia
| | - J Alejandro López
- School of Natural Sciences, Griffith University, Nathan, QLD 411, Australia; Oncogenomics Laboratory, QIMR Berghofer Medical Research Institute, Herston, Brisbane, QLD 4006, Australia
| | - Sriganesh Srihari
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Kum Kum Khanna
- Signal Transduction Laboratory, Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Herston, Brisbane, QLD 4006, Australia; School of Natural Sciences, Griffith University, Nathan, QLD 411, Australia.
| |
Collapse
|
30
|
Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015; 5:240. [PMID: 26579492 PMCID: PMC4620694 DOI: 10.3389/fonc.2015.00240] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/10/2015] [Indexed: 12/22/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination – a repair pathway activated in response to double-strand DNA breaks (DSB) – are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
Collapse
Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| |
Collapse
|
31
|
Milenic DE, Baidoo KE, Kim YS, Brechbiel MW. Evaluation of cetuximab as a candidate for targeted α-particle radiation therapy of HER1-positive disseminated intraperitoneal disease. MAbs 2015; 7:255-64. [PMID: 25587678 DOI: 10.4161/19420862.2014.985160] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although the epidermal growth factor receptor (EGFR), also known as HER1, has been studied for over a decade, it continues to be a molecule of great interest and focus of investigators for development of targeted therapies. The marketed monoclonal antibody cetuximab binds to HER1, and thus might serve as the basis for creation of imaging or therapies that target this receptor. The potential of cetuximab as a vehicle for the delivery of α-particle radiation was investigated in an intraperitoneal tumor mouse model. The effective working dose of 10 μCi of (212)Pb-cetuximab was determined from a dose (10-50 μCi) escalation study. Toxicity, as indicated by the lack of animal weight loss, was not evident at the 10 μCi dose of (212)Pb-cetuximab. A subsequent study demonstrated (212)Pb-cetuximab had a therapeutic efficacy similar to that of (212)Pb-trastuzumab (p = 0.588). Gemcitabine given 24 h prior to (212)Pb-cetuximab increased the median survival from 174 d to 283 d, but carboplatin suppressed the effectiveness of (212)Pb-cetuximab. Notably, concurrent treatment of tumor-bearing mice with (212)Pb-labeled cetuximab and trastuzumab provided therapeutic benefit that was greater than either antibody alone. In conclusion, cetuximab proved to be an effective vehicle for targeting HER1-expressing tumors with α-radiation for the treatment of disseminated intraperitoneal disease. These studies provide further evidence that the multimodality therapy regimens may have greater efficacy and benefit in the treatment of cancer patients.
Collapse
Key Words
- %ID/g, percent injected dose per gram
- 212Pb
- BSA, bovine serum albumin
- EGFR, epidermal growth factor receptor
- HER1
- HulgG, human immunoglobulin
- MS, median survival
- PBS, phosphate-buffered saline
- PET, positron emission tomography
- RIT, radioimmunotherapy
- TCMC, 1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane
- cetuximab
- i.p., intraperitoneal
- mAb, monoclonal antibody
- radioimmunotherapy
- s.c, subcutaneous
- α-particle
Collapse
Affiliation(s)
- Diane E Milenic
- a Radioimmune & Inorganic Chemistry Section; Radiation Oncology Branch; Center for Cancer Research; National Cancer Institute; National Institutes of Health ; Bethesda MD USA
| | | | | | | |
Collapse
|
32
|
Abstract
Radiopharmaceutical therapy (RPT) involves the use of radionuclides that are either conjugated to tumor-targeting agents (e.g., nanoscale constructs, antibodies, peptides, and small molecules) or concentrated in tissue through natural physiological mechanisms that occur predominantly in neoplastic or otherwise targeted cells (e.g., Graves disease). The ability to collect pharmacokinetic data by imaging and use this to perform dosimetry calculations for treatment planning distinguishes RPT from other systemic treatment modalities such as chemotherapy, wherein imaging is not generally used. Treatment planning has not been widely adopted, in part, because early attempts to relate dosimetry to outcome were not successful. This was partially because a dosimetry methodology appropriate to risk evaluation rather than efficacy and toxicity was being applied to RPT. The weakest links in both diagnostic and therapeutic dosimetry are the accuracy of the input and the reliability of the radiobiological models used to convert dosimetric data to the relevant biologic end points. Dosimetry for RPT places a greater demand on both of these weak links. To date, most dosimetric studies have been retrospective, with a focus on tumor dose-response correlations rather than prospective treatment planning. In this regard, transarterial radioembolization also known as intra-arterial radiation therapy, which uses radiolabeled ((90)Y) microspheres of glass or resin to treat lesions in the liver holds much promise for more widespread dosimetric treatment planning. The recent interest in RPT with alpha-particle emitters has highlighted the need to adopt a dosimetry methodology that specifically accounts for the unique aspects of alpha particles. The short range of alpha-particle emitters means that in cases in which the distribution of activity is localized to specific functional components or cell types of an organ, the absorbed dose will be equally localized and dosimetric calculations on the scale of organs or even voxels (~5mm) are no longer sufficient. This limitation may be overcome by using preclinical models to implement macromodeling to micromodeling. In contrast to chemotherapy, RPT offers the possibility of evaluating radiopharmaceutical distributions, calculating tumor and normal tissue absorbed doses, and devising a treatment plan that is optimal for a specific patient or specific group of patients.
Collapse
|
33
|
Keogan DM, Griffith DM. Current and potential applications of bismuth-based drugs. Molecules 2014; 19:15258-97. [PMID: 25251194 PMCID: PMC6271281 DOI: 10.3390/molecules190915258] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/04/2014] [Accepted: 09/04/2014] [Indexed: 02/06/2023] Open
Abstract
: Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.
Collapse
Affiliation(s)
- Donal M Keogan
- Centre for Synthesis & Chemical Biology, Department of Pharmaceutical & Medicinal Chemistry, Royal College of Surgeons in Ireland, 123 St. Stephens Green, Dublin 2, Ireland
| | - Darren M Griffith
- Centre for Synthesis & Chemical Biology, Department of Pharmaceutical & Medicinal Chemistry, Royal College of Surgeons in Ireland, 123 St. Stephens Green, Dublin 2, Ireland.
| |
Collapse
|
34
|
Huang F, Mazin AV. A small molecule inhibitor of human RAD51 potentiates breast cancer cell killing by therapeutic agents in mouse xenografts. PLoS One 2014; 9:e100993. [PMID: 24971740 PMCID: PMC4074124 DOI: 10.1371/journal.pone.0100993] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 05/30/2014] [Indexed: 01/06/2023] Open
Abstract
The homologous recombination pathway is responsible for the repair of DNA double strand breaks. RAD51, a key homologous recombination protein, promotes the search for homology and DNA strand exchange between homologous DNA molecules. RAD51 is overexpressed in a variety of cancer cells. Downregulation of RAD51 by siRNA increases radio- or chemo-sensitivity of cancer cells. We recently developed a specific RAD51 small molecule inhibitor, B02, which inhibits DNA strand exchange activity of RAD51 in vitro. In this study, we used human breast cancer cells MDA-MB-231 to investigate the ability of B02 to inhibit RAD51 and to potentiate an anti-cancer effect of chemotherapeutic agents including doxorubicin, etoposide, topotecan, and cisplatin. We found that the combination of B02 with cisplatin has the strongest killing effect on the cancer cells. We then tested the effect of B02 and cisplatin on the MDA-MB-231 cell proliferation in mouse xenografts. Our results showed that B02 significantly enhances the therapeutic effect of cisplatin on tumor cells in vivo. Our current data demonstrate that use of RAD51-specific small molecule inhibitor represents a feasible strategy of a combination anti-cancer therapy.
Collapse
Affiliation(s)
- Fei Huang
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Alexander V. Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| |
Collapse
|
35
|
Jin L, Lim M, Zhao S, Sano Y, Simone BA, Savage JE, Wickstrom E, Camphausen K, Pestell RG, Simone NL. The metastatic potential of triple-negative breast cancer is decreased via caloric restriction-mediated reduction of the miR-17~92 cluster. Breast Cancer Res Treat 2014; 146:41-50. [PMID: 24863696 DOI: 10.1007/s10549-014-2978-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 04/19/2014] [Indexed: 12/17/2022]
Abstract
Caloric restriction (CR) has been shown to cause tumor regression in models of triple-negative breast cancer (TNBC), and the regression is augmented when coupled with ionizing radiation (IR). In this study, we sought to determine if the molecular interaction between CR and IR could be mediated by microRNA (miR). miR arrays revealed 3 miRs in the miR-17~92 cluster as most significantly down regulated when CR is combined with IR. In vivo, CR and IR down regulated miR-17/20 in 2 TNBC models. To elucidate the mechanism by which this cluster regulates the response to CR, cDNA arrays were performed and the top 5 statistically significant gene ontology terms with high fold changes were all associated with extracellular matrix (ECM) and metastases. In silico analysis revealed 4 potential targets of the miR-17~92 cluster related to ECM: collagen 4 alpha 3, laminin alpha 3, and metallopeptidase inhibitors 2 and 3, which were confirmed by luciferase assays. The overexpression or silencing of miR-17/20a demonstrated that those miRs directly affected the ECM proteins. Furthermore, we found that CR-mediated inhibition of miR-17/20a can regulate the expression of ECM proteins. Functionally, we demonstrate that CR decreases the metastatic potential of cells which further demonstrates the importance of the ECM. In conclusion, CR can be used as a potential treatment for cancer because it may alter many molecular targets concurrently and decrease metastatic potential for TNBC.
Collapse
Affiliation(s)
- Lianjin Jin
- Department of Radiation Oncology, Thomas Jefferson University, Phiadelphia, PA, 19107, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
INTRODUCTION The EGFR has been associated with the pathogenesis and progression of breast cancer. Treatment based on an EGFR target is emerging as a promising option, especially in combination with conventional therapies. Unfortunately, there are no validated predictor biomarkers, and combinatorial treatments are meeting new resistance. AREAS COVERED The purpose of this review is to summarize the existing treatments and the current research based on targeting the EGFR pathway. EXPERT OPINION The existing EGFR treatments in breast cancer have shown limited benefit. The combination of the monoclonal antibody cetuximab and platinum salts achieves a 15 - 20% response rate. The effectiveness of tyrosine kinase inhibitors is not completely clear, showing modest or no benefits. Gefitinib treatment has offered some promising results in estrogen receptor + breast cancer. However, it has not been identified as a predictive factor for the appropriate selection of patients. Radioimmunotherapy with anti-EGFR radiolabeled antibodies is a promising strategy in BRCA-mutated breast cancer, but it still requires clinical confirmation. Nevertheless, the crosstalk between pathways frequently leads to treatment resistance. Current research is focused on increasing knowledge about the mechanisms of response and the discovery of predictive markers. Targeting several pathways simultaneously and a correct selection of patients seem essential.
Collapse
Affiliation(s)
- Ana Lluch
- Hospital Clinico Universitario, INCLIVA Biomedical Research Institute, Department of Oncology and Hematology , Valencia , Spain +0034 963987659 ;
| | | | | |
Collapse
|
37
|
Sihver W, Pietzsch J, Krause M, Baumann M, Steinbach J, Pietzsch HJ. Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy. Pharmaceuticals (Basel) 2014; 7:311-38. [PMID: 24603603 PMCID: PMC3978494 DOI: 10.3390/ph7030311] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/11/2014] [Accepted: 02/21/2014] [Indexed: 01/09/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a) chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b) with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.
Collapse
Affiliation(s)
- Wiebke Sihver
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Mechthild Krause
- Department of Radiation Oncology and OncoRay, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
| | - Michael Baumann
- Department of Radiation Oncology and OncoRay, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden 01307, Germany.
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| | - Hans-Jürgen Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, Dresden 01328, Germany.
| |
Collapse
|
38
|
DNA-PK inhibition by NU7441 sensitizes breast cancer cells to ionizing radiation and doxorubicin. Breast Cancer Res Treat 2013; 143:47-55. [DOI: 10.1007/s10549-013-2785-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 11/21/2013] [Indexed: 10/26/2022]
|