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Cancer Immunology, Immunotherapy : CII Jan 2014Cancer, the most devastating chronic disease affecting humankind, is treated primarily by surgery, chemotherapy, and radiation therapy. Surgery and radiotherapy are... (Review)
Review
Cancer, the most devastating chronic disease affecting humankind, is treated primarily by surgery, chemotherapy, and radiation therapy. Surgery and radiotherapy are mainly used for debulking the primary tumor, while chemotherapy is the most efficient anti-metastatic treatment. To control better metastatic cancer, the host immune system should be stimulated. Yet, successful specific stimulation of the immune system against tumors was seldom achieved even in antigenic tumors. Our working hypothesis is that aggressive in situ tumor ablation can release tumor antigens and danger signals, which will enhance anti-tumor T cell responses resulting in the destruction of residual malignant cells in primary tumors and distant metastases. We developed two efficient in situ ablation treatments for solid cancer, which can be used to destroy the primary tumors and stimulate anti-tumor immune responses. The first treatment, electrochemical ablation, is applied through intratumoral electrodes, which deliver unipolar-pulsed electric currents. The second treatment, diffusing alpha-emitters radiation therapy (DaRT), is based on intratumoral (224)Ra-loaded wire(s) that release by recoil its daughter atoms. These short-lived alpha-emitting atoms spread in the tumor and spray it with lethal alpha particles. It was confirmed that these treatments effectively destroy various malignant animal and human primary solid tumors. As a consequence of such tumor ablation, tumor-derived antigenic material was released and provoked systemic T cell-dependent anti-tumor immunological reactions. These reactions conferred protection against a secondary tumor challenge and destroyed remaining malignant cells in the primary tumor as well as in distant metastases. Such anti-tumor immune responses could be further amplified by the immune adjuvant, CpG. Electrochemical ablation or DaRT together with chemotherapy and immunostimulatory agents can serve as treatment protocols for solid metastatic tumors and can be applied instead of or in combination with surgery.
Topics: Ablation Techniques; Alpha Particles; Animals; Antigens, Neoplasm; Antineoplastic Agents; Electrochemistry; Humans; Immunologic Memory; Immunotherapy; Mice; Neoplasm Metastasis; Neoplasms; Radium; Time Factors
PubMed: 23955682
DOI: 10.1007/s00262-013-1462-2 -
PloS One 2023DNA double strand breaks (DSBs) are a deleterious form of DNA damage. Densely ionising alpha radiation predominantly induces complex DSBs and sparsely ionising gamma...
DNA double strand breaks (DSBs) are a deleterious form of DNA damage. Densely ionising alpha radiation predominantly induces complex DSBs and sparsely ionising gamma radiation-simple DSBs. We have shown that alphas and gammas, when applied simultaneously, interact in producing a higher DNA damage response (DDR) than predicted by additivity. The mechanisms of the interaction remain obscure. The present study aimed at testing whether the sequence of exposure to alphas and gammas has an impact on the DDR, visualised by live NBS1-GFP (green fluorescent protein) focus dynamics in U2OS cells. Focus formation, decay, intensity and mobility were analysed up to 5 h post exposure. Focus frequencies directly after sequential alpha → gamma and gamma → alpha exposure were similar to gamma alone, but gamma → alpha foci quickly declined below the expected values. Focus intensities and areas following alpha alone and alpha → gamma were larger than after gamma alone and gamma → alpha. Focus movement was most strongly attenuated by alpha → gamma. Overall, sequential alpha → gamma exposure induced the strongest change in characteristics and dynamics of NBS1-GFP foci. Possible explanation is that activation of the DDR is stronger when alpha-induced DNA damage precedes gamma-induced DNA damage.
Topics: Alpha Particles; Gamma Rays; Records; DNA Breaks, Double-Stranded; DNA Damage; Green Fluorescent Proteins
PubMed: 37307266
DOI: 10.1371/journal.pone.0286902 -
Theranostics 2024Targeted alpha particle therapy (TAT) has emerged as a promising strategy for the treatment of prostate cancer (PCa). Actinium-225 (Ac), a potent alpha-emitting... (Review)
Review
Targeted alpha particle therapy (TAT) has emerged as a promising strategy for the treatment of prostate cancer (PCa). Actinium-225 (Ac), a potent alpha-emitting radionuclide, may be incorporated into targeting vectors, causing robust and in some cases sustained antitumor responses. The development of radiolabeling techniques involving EDTA, DOTA, DOTPA, and Macropa chelators has laid the groundwork for advancements in this field. At the forefront of clinical trials with Ac in PCa are PSMA-targeted TAT agents, notably [Ac]Ac-PSMA-617, [Ac]Ac-PSMA-I&T and [Ac]Ac-J591. Ongoing investigations spotlight [Ac]Ac-hu11B6, [Ac]Ac-YS5, and [Ac]Ac-SibuDAB, targeting hK2, CD46, and PSMA, respectively. Despite these efforts, hurdles in Ac production, daughter redistribution, and a lack of suitable imaging techniques hinder the development of TAT. To address these challenges and additional advantages, researchers are exploring alpha-emitting isotopes including Th, Ra, At, Bi, Pb or Tb, providing viable alternatives for TAT.
Topics: Humans; Male; Actinium; Prostatic Neoplasms; Alpha Particles; Radiopharmaceuticals; Animals
PubMed: 38773983
DOI: 10.7150/thno.96403 -
Journal of Nuclear Medicine : Official... Jun 2018With a short particle range and high linear energy transfer, α-emitting radionuclides demonstrate high cell-killing efficiencies. Even with the existence of numerous... (Review)
Review
With a short particle range and high linear energy transfer, α-emitting radionuclides demonstrate high cell-killing efficiencies. Even with the existence of numerous radionuclides that decay by α-particle emission, only a few of these can reasonably be exploited for therapeutic purposes. Factors including radioisotope availability and physical characteristics (e.g., half-life) can limit their widespread dissemination. The first part of this review will explore the diversity, basic radiochemistry, restrictions, and hurdles of α-emitters.
Topics: Alpha Particles; Humans; Isotope Labeling; Radiochemistry
PubMed: 29545378
DOI: 10.2967/jnumed.116.186338 -
Nuclear Medicine and Biology 2021In oncology, the holy grail of radiotherapy is specific radiation dose deposition in tumours with minimal healthy tissue toxicity. If used appropriately, injectable,... (Review)
Review
In oncology, the holy grail of radiotherapy is specific radiation dose deposition in tumours with minimal healthy tissue toxicity. If used appropriately, injectable, systemic radionuclide therapies could meet these criteria, even for treatment of micrometastases and single circulating tumour cells. The clinical use of α and β particle-emitting molecular radionuclide therapies is rising, however clinical translation of Auger electron-emitting radionuclides is hampered by uncertainty around their exact subcellular localisation, which in turn affects the accuracy of dosimetry. This review aims to discuss and compare the advantages and disadvantages of various subcellular localisation methods available to localise radiopharmaceuticals and radionuclides for in vitro investigations.
Topics: Alpha Particles; Radiation Dosage; Radiopharmaceuticals
PubMed: 33964707
DOI: 10.1016/j.nucmedbio.2021.03.010 -
International Journal of Molecular... Dec 2017The skeleton is the target tissue for many types of tumors, and, recently, the survival of patients with prostate cancer metastasis has been increased using α-emitting... (Review)
Review
The skeleton is the target tissue for many types of tumors, and, recently, the survival of patients with prostate cancer metastasis has been increased using α-emitting drugs known as targeted α therapies. The use of α-radiopharmaceuticals in medicine was hypothesized at the beginning of the nineteenth century after the observation that α-radionuclides were associated with high cell-killing energy and low tissue penetration in healthy tissues. In the prostate cancer (PC) scenario, current research suggests that this class of radiopharmaceuticals has limited toxicity, and that the mechanism of action does not overlap with pre-existing drugs, allowing us to extend therapeutic armaments and address medical oncology towards personalized and precision medicine. Ongoing studies may extend these benefits also to bone metastases deriving from other neoplasms. The aim of this review is to summarize the current research on targeted α therapies and try to identify the right patient to be treated in the right time in order to integrate in these medications in the every-day clinical practice.
Topics: Alpha Particles; Bone Neoplasms; Brachytherapy; Dose-Response Relationship, Radiation; Humans; Male; Practice Guidelines as Topic; Prostatic Neoplasms; Radioisotopes; Radium; Randomized Controlled Trials as Topic
PubMed: 29283383
DOI: 10.3390/ijms19010074 -
The Open Biochemistry Journal 2012Alpha (α)-particle emitters are probable isotopes to be used in a terrorist attack. The development of biological assessment tools to identify those who have handled...
Alpha (α)-particle emitters are probable isotopes to be used in a terrorist attack. The development of biological assessment tools to identify those who have handled these difficult to detect materials would be an asset to our current forensic capacity. In this study, for the purposes of biomarker discovery, human keratinocytes were exposed to α-particle and X-radiation (0.98 Gy/h at 0, 0.5, 1.0, 1.5 Gy) and assessed for differential gene and protein expression using microarray and Bio-Plex technology, respectively. Secretomic analysis of supernatants showed expression of two pro-inflammatory cytokines (IL-13 and PDGF-bb) to be exclusively affected in α-particle exposed cells. The highest dose of α-particle radiation modulated a total of 67 transcripts (fold change>|1.5|, (False discovery rate) FDR<0.05) in exposed cells. Several genes which responded with high expression levels (>2 fold) included KIF20A, NEFM, C7orf10, HIST1H2BD, BMP6, and HIST1H2AC. Among the high expressing genes, five (CCNB2, BUB1, NEK2, CDC20, AURKA) were also differentially expressed at the medium (1.0 Gy) dose however, these genes were unmodulated following exposure to X-irradiation. Networks of these genes clustered around tumor protein-53 and transforming growth factor-beta signaling. This study has identified some potential gene /protein responses and networks that may be validated further to confirm their specificity and potential to be signature biomarkers of α-particle exposure.
PubMed: 23002402
DOI: 10.2174/1874091X01206010103 -
Tumour Biology : the Journal of the... Jun 2012The effectiveness of targeted α-therapy (TAT) can be explained by the properties of α-particles. Alpha particles are helium nuclei and are ~8,000 times larger than... (Review)
Review
The effectiveness of targeted α-therapy (TAT) can be explained by the properties of α-particles. Alpha particles are helium nuclei and are ~8,000 times larger than β(-)-particles (electrons). When emitted from radionuclides that decay via an α-decay pathway, they release enormous amounts of energy over a very short distance. Typically, the range of α-particles in tissue is 50-100 μm and they have high linear energy transfer (LET) with a mean energy deposition of 100 keV/μm, providing a more specific tumor cell killing ability without damage to the surrounding normal tissues than β(-)-emitters. Due to these properties, the majority of pre-clinical and clinical trials have demonstrated that α-emitters such as (225)Ac, (211)At, (212)Bi, (213)Bi, (212)Pb, (223)Ra, and (227)Th are ideal for the treatment of smaller tumor burdens, micrometastatic disease, and disseminated disease. Even though these α-emitters have favorable properties, the development of TAT has been limited by high costs, unresolved chemistry, and limited availability of the radionuclides. To overcome these limitations, more potent isotopes, additional sources, and more efficient isotope production methods should be addressed. Furthermore, better chelation and labeling methods with the improvements of isotope delivery, targeting vehicles, molecular targets, and identification of appropriate clinical applications are still required.
Topics: Alpha Particles; Animals; Clinical Trials as Topic; Drug Evaluation, Preclinical; Humans; Neoplasms; Radioimmunotherapy; Radioisotopes
PubMed: 22143940
DOI: 10.1007/s13277-011-0286-y -
Scientific Reports Jul 2023There is agreement that high-LET radiation has a high Relative Biological Effectiveness (RBE) when delivered as a single treatment, but how it interacts with radiations...
There is agreement that high-LET radiation has a high Relative Biological Effectiveness (RBE) when delivered as a single treatment, but how it interacts with radiations of different qualities, such as X-rays, is less clear. We sought to clarify these effects by quantifying and modelling responses to X-ray and alpha particle combinations. Cells were exposed to X-rays, alpha particles, or combinations, with different doses and temporal separations. DNA damage was assessed by 53BP1 immunofluorescence, and radiosensitivity assessed using the clonogenic assay. Mechanistic models were then applied to understand trends in repair and survival. 53BP1 foci yields were significantly reduced in alpha particle exposures compared to X-rays, but these foci were slow to repair. Although alpha particles alone showed no inter-track interactions, substantial interactions were seen between X-rays and alpha particles. Mechanistic modelling suggested that sublethal damage (SLD) repair was independent of radiation quality, but that alpha particles generated substantially more sublethal damage than a similar dose of X-rays, [Formula: see text]. This high RBE may lead to unexpected synergies for combinations of different radiation qualities which must be taken into account in treatment design, and the rapid repair of this damage may impact on mechanistic modelling of radiation responses to high LETs.
Topics: Radiation, Ionizing; Alpha Particles; Biological Assay; DNA Damage; Radiation Tolerance
PubMed: 37433844
DOI: 10.1038/s41598-023-38295-3 -
Dalton Transactions (Cambridge, England... Nov 2007Monoclonal antibodies have become a viable strategy for the delivery of therapeutic, particle emitting radionuclides specifically to tumor cells to either augment... (Review)
Review
Monoclonal antibodies have become a viable strategy for the delivery of therapeutic, particle emitting radionuclides specifically to tumor cells to either augment anti-tumor action of the native antibodies or to solely take advantage of their action as targeting vectors. Proper and rational selection of radionuclide and antibody combinations is critical to making radioimmunotherapy (RIT) a standard therapeutic modality due to the fundamental and significant differences in the emission of either alpha- and beta-particles. The alpha-particle has a short path length (50-80 microm) that is characterized by high linear energy transfer (100 keV microm(-1)). Actively targeted alpha-therapy potentially offers a more specific tumor cell killing action with less collateral damage to the surrounding normal tissues than beta-emitters. These properties make targeted alpha-therapy an appropriate therapy to eliminate minimal residual or micrometastatic disease. RIT using alpha-emitters such as (213)Bi, (211)At, (225)Ac, and others has demonstrated significant activity in both in vitro and in vivo model systems. Limited numbers of clinical trials have progressed to demonstrate safety, feasibility, and therapeutic activity of targeted alpha-therapy, despite having to traverse complex obstacles. Further advances may require more potent isotopes, additional sources and more efficient means of isotope production. Refinements in chelation and/or radiolabeling chemistry combined with rational improvements of isotope delivery, targeting vectors, molecular targets, and identification of appropriate clinical applications remain as active areas of research. Ultimately, randomized trials comparing targeted alpha-therapy combined with integration into existing standards of care treatment regimens will determine the clinical utility of this modality.
Topics: Alpha Particles; Antibodies, Monoclonal; Humans; Neoplasms; Radioimmunotherapy
PubMed: 17992276
DOI: 10.1039/b704726f