Search

Based on the need for radiobiological databases, in this work, we mined experimental ionizing radiation data of human cells treated with X-rays, γ-rays, carbon ions, protons and α-particles, by manually searching the relevant literature in PubMed from 1980 until 2024. In order to calculate normal and tumor cell survival α and β coefficients of the linear quadratic (LQ) established model, as well as the initial values of the double-strand breaks (DSBs) in DNA, we used WebPlotDigitizer and Python programming language. We also produced complex DNA damage results through the fast Monte Carlo code MCDS in order to complete any missing data. The calculated α/β values are in good agreement with those valued reported in the literature, where α shows a relatively good association with linear energy transfer (LET), but not β. In general, a positive correlation between DSBs and LET was observed as far as the experimental values are concerned. Furthermore, we developed a biophysical prediction model by using machine learning, which showed a good performance for α, while it underscored LET as the most important feature for its prediction. In this study, we designed and developed the novel radiobiological 'RadPhysBio' database for the prediction of irradiated cell survival (α and β coefficients of the LQ model). The incorporation of machine learning and repair models increases the applicability of our results and the spectrum of potential users. [ABSTRACT FROM AUTHOR]

Simple Summary: The nature of different types of ionizing radiation is central to the modality of affecting biological targets. The main data library on radiotherapy effects we can access is on photon sources, and any other type of radiation is compared to that, not always considering that different physical features might contribute in quite different ways to the quality of visible effects. A large body of study already supports this vision, but a lot of work is still to be done, particularly on irradiated healthy tissue in the vicinity of the cancer target. This study aims to gain information on the effects of anti-cancer therapeutic protons as a function of radiation dose and time post-irradiation on healthy cardiac tissue through the analysis of transcriptionally activated genes and relative molecular pathways. Proton beam therapy is considered a step forward with respect to electromagnetic radiation, thanks to the reduction in the dose delivered. Among unwanted effects to healthy tissue, cardiovascular complications are a known long-term radiotherapy complication. The transcriptional response of cardiac tissue from xenografted BALB/c nude mice obtained at 3 and 10 days after proton irradiation covering both the tumor region and the underlying healthy tissue was analyzed as a function of dose and time. Three doses were used: 2 Gy, 6 Gy, and 9 Gy. The intermediate dose had caused the greatest impact at 3 days after irradiation: at 2 Gy, 219 genes were differently expressed, many of them represented by zinc finger proteins; at 6 Gy, there were 1109, with a predominance of genes involved in energy metabolism and responses to stimuli; and at 9 Gy, there were 105, mainly represented by zinc finger proteins and molecules involved in the regulation of cardiac function. After 10 days, no significant effects were detected, suggesting that cellular repair mechanisms had defused the potential alterations in gene expression. The nonlinear dose–response curve indicates a need to update the models built on photons to improve accuracy in health risk prediction. Our data also suggest a possible role for zinc finger protein genes as markers of proton therapy efficacy. [ABSTRACT FROM AUTHOR]

Boron-Neutron Capture Therapy (BNCT) is a tumor-selective radiotherapy, based on the nuclear capture reaction 10B(n,α)7Li producing short range α-particles and recoiling 7Li nuclei exclusively confined to boron-enriched cancer cells. These particles possess high Linear Energy Transfer (LET) and mainly generate clustered DNA strand breaks, which are less faithfully restored by intracellular repair. Mis-rejoined breaks yield chromosome aberrations (CAs), which, for high-LET radiation, are more complex in nature than after sparsely ionizing photons/electrons used in conventional radiotherapy, which leads to increased cell-killing ability. However, such a radiobiological tenet of BNCT has been scantily studied at the DNA level. Therefore, the aim of this work was to evaluate CAs induced by BNCT in comparison to X-rays in genomically stable normal human epithelial mammary MCF10A cells. Two Fluorescence In Situ Hybridization (FISH)-based techniques were applied to calyculin A-induced prematurely condensed chromosomes: Whole Chromosome Painting and multicolor(m)-FISH. Not only did BNCT induce a greater CA frequency than X-ray irradiation, but m-FISH karyotype-wide analysis confirmed that CAs following BNCT exhibited a much higher degree of complexity compared to X-rays. To our knowledge, this is the first time that such evidence supporting the radiobiological superiority of BNCT has been shown. [ABSTRACT FROM AUTHOR]

Valerian salad and lettuce are edible species that are easy to grow rapidly, and have traits useful for commercial purposes. The consumption of these species is increasing worldwide for their nutritional properties. Seed germination and seedling development are critical stages in the life cycle of plants. Seed priming, including the use of high-energy radiation, is a set of techniques based on the idea that low stress levels stimulate plant responses, thereby improving seed germination and plant growth. In this study, we evaluated in hydroponic culture (i) the germination performance; (ii) morphological traits; and (iii) antioxidant and phenol contents at different endpoints in Lactuca sativa and Valerianella locusta that were developed from seeds exposed to X-rays (1 Gy and 10 Gy doses). Under radiation, biomass production increased in both species, especially in lettuce, where also a reduction in the mean germination time occurred. Radiation increased the level of phenols during the first growth weeks, under both doses for lettuce, and only 1 Gy was required for valerian salad. The species-specific responses observed in this research suggest that the use of radiations in seed priming needs to be customized to the species. [ABSTRACT FROM AUTHOR]

Lipids are organic compounds that contribute to numerous cellular functions. Fourier Transform Infrared spectroscopy can be particularly useful in investigating the biochemical features of the lipid content of cells and their changes induced by interaction with physicochemical external agents. In the present work, we aim to investigate the extract of lipids from human cells to compare the results obtained by using two different geometries: transmission and attenuated total reflectance. Multiple acquisitions of spectra were carried out and statistical criteria were applied for monitoring and comparing them. The positive and negative aspects of the two examined acquisition modes are presented and discussed. [ABSTRACT FROM AUTHOR]

An analytical method based on tandem mass spectrometry-shotgun is presently proposed to obtain sphingolipidomic profiles useful for the characterization of lipid extract from X-ray-exposed and unexposed hepatocellular carcinoma cells (HepG2). To obtain a targeted lipidic profile from a specific biological system, the best extraction method must be identified before instrumental analysis. Accordingly, four different classic lipid extraction protocols were compared in terms of efficiency, specificity, and reproducibility. The performance of each procedure was evaluated using the Fourier-transform infrared spectroscopic technique; subsequently, the quality of extracts was estimated using electrospray ionization tandem mass spectrometry. The selected procedure based on chloroform/methanol/water was successfully used in mass spectrometry-based shotgun sphingolipidomics, allowing for evaluation of the response of cells to X-ray irradiation, the most common anticancer therapy. Using a relative quantitative approach, the changes in the sphingolipid profiles of irradiated cell extracts were demonstrated, confirming that lipidomic technologies are also useful tools for studying the key sphingolipid role in regulating cancer growth during radiotherapy. [ABSTRACT FROM AUTHOR]

Due to its potential applications in cultivated plants, ionizing radiation (IR) and its effect on organisms is increasingly studied. Here we measured the effects of ionizing radiation on Eruca sativa by analyzing plants from irradiated seeds (1 and 10 Gy) grown in hydroponics. We measured several morpho-physiological traits and genotoxicity. Radiation stress induced a noticeable variability of the morphophysiological traits highlighting decreased plant vigor. Shoot length and leaf number were significantly higher in 1 Gy-treated samples, whereas root length was significantly higher in 10 Gy treated plants. Stomata number significantly increased with IR dose, whereas both pigment and Rubisco content decreased under radiation stress. Phenol content significantly increased in 1 Gy treated samples, otherwise from total antioxidants, which were not different from control. Most results could find a feasible explanation in a hormesis-like pattern and in a decreased plant vigor under radiation stress. IR induced genotoxic damage, evaluated by ISSR markers, in 15 day old leaves; specifically, a severe decrease in the genome template stability was observed. However, a partial recovery occurred after 2 weeks, especially under the lowest dose (i.e., 1 Gy), suggesting that DNA damage detection and repair mechanisms are active. Pigment content and genotoxic damage may serve as proxies for evaluating plant responses to IR stress, since they show univocal dose-dependent trends. The use of more checkpoints for analyses and more doses over a wider range, as well as the focus on different metabolites, could help elucidate plant response in terms of morpho-physiological changes. [ABSTRACT FROM AUTHOR]

The OLC Presence Exacerbates Radiation-Induced DNA Damage in Cancer Cells When prostate DU145 and pancreatic PANC-1 cancer cell lines were subjected to the same experimental conditions as those adopted for the non-cancer cell lines HUVEC and MCF-10A, that is 24-h treatment with, and irradiation in the presence of, 12.5 g/mL OLC, the measured frequency of MN per BN cell was significantly higher than that observed in cancer cells irradiated without OLC (Figure 8). At the same dose, the protection afforded by OLC in MCF-10A was less but still statistically different (Figure 7B), with a yield of 0.945 MN/cell in the absence of OLC compared to a value of 0.831 MN/cell in OLC-treated MCF-10A cells ( I p i < 0.001). To assess the radiomodulating properties of OLC, the water-soluble extract was added at a final concentration of 12.5 L/mL to exponentially growing cells seeded at appropriate densities in T12.5 or T25 tissue culture flasks for senescence time-course experiments (around 1.5 × 10 SP 4 sp and 5 × 10 SP 4 sp cells/flask, respectively) or in Nunc™ (Thermo Fisher Scientific, Waltham, MA, USA) slide flasks (around 2 × 10 SP 4 sp cells/slide flask) for DNA damage evaluation by the CBMN assay. [Extracted from the article]

Radiotherapy (RT) with accelerated beams of charged particles (protons and carbon ions), also known as hadrontherapy, is a treatment modality that is increasingly being adopted thanks to the several benefits that it grants compared to conventional radiotherapy (CRT) treatments performed by means of high-energy photons/electrons. Hence, information about the biomolecular effects in exposed cells caused by such particles is needed to better realize the underlying radiobiological mechanisms and to improve this therapeutic strategy. To this end, Fourier transform infrared microspectroscopy (μ-FT-IR) can be usefully employed, in addition to long-established radiobiological techniques, since it is currently considered a helpful tool for examining radiation-induced cellular changes. In the present study, MCF-10A breast cells were chosen to evaluate the effects of proton exposure using μ-FT-IR. They were exposed to different proton doses and fixed at various times after exposure to evaluate direct effects due to proton exposure and the kinetics of DNA damage repair. Irradiated and control cells were examined in transflection mode using low-e substrates that have been recently demonstrated to offer a fast and direct way to examine proton-exposed cells. The acquired spectra were analyzed using a deconvolution procedure and a ratiometric approach, both of which showed the different contributions of DNA, protein, lipid, and carbohydrate cell components. These changes were particularly significant for cells fixed 48 and 72 h after exposure. Lipid changes were related to variations in membrane fluidity, and evidence of DNA damage was highlighted. The analysis of the Amide III band also indicated changes that could be related to different enzyme contributions in DNA repair. [ABSTRACT FROM AUTHOR]

Featured Application: The application of the work described herein is twofold: the possibility of routinely irradiating biological samples with high accuracy in energy and dose at a low-energy particle accelerator to gain insights into fundamental mechanisms of the biological action of charged particles; in a broader scenario, the possibility to potentiate the therapeutic capabilities of protontherapy through a method based on a nuclear physics reaction. Protontherapy (PT) is a fast-growing cancer therapy modality thanks to much-improved normal tissue sparing granted by the charged particles' inverted dose-depth profile. Protons, however, exhibit a low biological effectiveness at clinically relevant energies. To enhance PT efficacy and counteract cancer radioresistance, Proton–Boron Capture Therapy (PBCT) was recently proposed. PBCT exploits the highly DNA-damaging α-particles generated by the p + 11B→3α (pB) nuclear reaction, whose cross-section peaks for proton energies of 675 keV. Although a significant enhancement of proton biological effectiveness by PBCT has been demonstrated for high-energy proton beams, validation of the PBCT rationale using monochromatic proton beams having energy close to the reaction cross-section maximum is still lacking. To this end, we implemented a novel setup for radiobiology experiments at a 3-MV tandem accelerator; using a scattering chamber equipped with an Au foil scatterer for beam diffusion on the biological sample, uniformity in energy and fluence with uncertainties of 2% and 5%, respectively, was achieved. Human cancer cells were irradiated at this beamline for the first time with 685-keV protons. The measured enhancement in cancer cell killing due to the 11B carrier BSH was the highest among those thus far observed, thereby corroborating the mechanistic bases of PBCT. [ABSTRACT FROM AUTHOR]

CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) was the first Italian protontherapy facility dedicated to the treatment of ocular neoplastic pathologies. It is in operation at the LNS Laboratories of the Italian Institute for Nuclear Physics (INFN-LNS) and to date, 500 patients have been successfully treated. Even though proton therapy has demonstrated success in clinical settings, there is still a need for more accurate models because they are crucial for the estimation of clinically relevant RBE values. Since RBE can vary depending on several physical and biological parameters, there is a clear need for more experimental data to generate predictions. Establishing a database of cell survival experiments is therefore useful to accurately predict the effects of irradiations on both cancerous and normal tissue. The main aim of this work was to compare RBE values obtained from in-vitro experimental data with predictions made by the LEM II (Local Effect Model), Monte Carlo approaches, and semi-empirical models based on LET experimental measurements. For this purpose, the 92.1 uveal melanoma and ARPE-19 cells derived from normal retinal pigmented epithelium were selected and irradiated in the middle of clinical SOBP of the CATANA proton therapy facility. The remarkable results show the potentiality of using microdosimetric spectrum, Monte Carlo simulations and LEM model to predict not only the RBE but also the survival curves. [ABSTRACT FROM AUTHOR]

Fourier transform infrared micro-spectroscopy (μ-FT-IR) is nowadays considered a valuable tool for investigating the changes occurring in human cells after exposure to ionizing radiation. Recently, considerable attention has been devoted to the use of this optical technique in the study of cells exposed to proton beams, that are being increasingly adopted in cancer therapy. Different experimental configurations are used for proton irradiation and subsequent spectra acquisition. To facilitate the use of μ-FT-IR, it may be useful to investigate new experimental approaches capable of speeding up and simplifying the irradiation and measurements phases. Here, we propose the use of low-e-substrates slides for cell culture, allowing the irradiation and spectra acquisition in transflection mode in a fast and direct way. In recent years, there has been a wide debate about the validity of these supports, but many researchers agree that the artifacts due to the presence of the electromagnetic standing wave effects are negligible in many practical cases. We investigated human normal breast cells (MCF-10 cell line) fixed immediately after the irradiation with graded proton radiation doses (0, 0.5, 2, and 4 Gy). The spectra obtained in transflection geometry showed characteristics very similar to those present in the spectra acquired in transmission geometry and confirm the validity of the chosen approach. The analysis of spectra indicates the occurrence of significant changes in DNA and lipids components of cells. Modifications in protein secondary structure are also evidenced. [ABSTRACT FROM AUTHOR]

The ability of Fourier transform infrared (FTIR) spectroscopy in analyzing cells at a molecular level was exploited for investigating the biochemical changes induced in protein, nucleic acid, lipid, and carbohydrate content of cells after irradiation by graded X-ray doses. Infrared spectra from in vitro SH-SY5Y neuroblastoma cells following exposure to X-rays (0, 2, 4, 6, 8, 10 Gy) were analyzed using a ratiometric approach by evaluating the ratios between the absorbance of significant peaks. The spectroscopic investigation was performed on cells fixed immediately (t0 cells) and 24 h (t24 cells) after irradiation to study both the initial radiation-induced damage and the effect of the ensuing cellular repair processes. The analysis of infrared spectra allowed us to detect changes in proteins, lipids, and nucleic acids attributable to X-ray exposure. The ratiometric analysis was able to quantify changes for the protein, lipid, and DNA components and to suggest the occurrence of apoptosis processes. The ratiometric study of Amide I band indicated also that the secondary structure of proteins was significantly modified. The comparison between the results from t0 and t24 cells indicated the occurrence of cellular recovery processes. The adopted approach can provide a very direct way to monitor changes for specific cellular components and can represent a valuable tool for developing innovative strategies to monitor cancer radiotherapy outcome. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is the most common cancer in women, highly heterogeneous at both the clinical and molecular level. Radiation therapy (RT) represents an efficient modality to treat localized tumor in BC care, although the choice of a unique treatment plan for all BC patients, including RT, may not be the best option. Technological advances in RT are evolving with the use of charged particle beams (i.e. protons) which, due to a more localized delivery of the radiation dose, reduce the dose administered to the heart compared with conventional RT. However, few data regarding proton-induced molecular changes are currently available. The aim of this study was to investigate and describe the production of immunological molecules and gene expression profiles induced by proton irradiation. We performed Luminex assay and cDNA microarray analyses to study the biological processes activated following irradiation with proton beams, both in the non-tumorigenic MCF10A cell line and in two tumorigenic BC cell lines, MCF7 and MDA-MB-231. The immunological signatures were dose dependent in MCF10A and MCF7 cell lines, whereas MDA-MB-231 cells show a strong pro-inflammatory profile regardless of the dose delivered. Clonogenic assay revealed different surviving fractions according to the breast cell lines analyzed. We found the involvement of genes related to cell response to proton irradiation and reported specific cell line- and dose-dependent gene signatures, able to drive cell fate after radiation exposure. Our data could represent a useful tool to better understand the molecular mechanisms elicited by proton irradiation and to predict treatment outcome [ABSTRACT FROM AUTHOR]

Purpose: Proton therapy has been recently proposed as a radiotherapy form for breast cancer treatment in view of its potentially decreased normal-tissue toxicity compared with conventional photon-based radiotherapy. However, the risks for the healthy tissue cannot be completely eliminated. In the present study, the suitability of Raman spectroscopy to monitor the radiosensitivity of normal cells exposed to clinical proton beam was investigated. Materials and methods: MCF10A normal human breast cells were irradiated at two different proton doses: 0.5 Gy and 4 Gy. They were fixed immediately after irradiation and measured by means of Raman spectroscopy technique. The obtained data were analyzed both by evaluating the intensity ratio of specific Raman spectral peaks and through Multivariate Distance Matrix Regression technique. Results: Certain Raman peaks associated with DNA showed a systematic suppression at both dose levels. In particular, the intensity of a Raman peak at 784 cm−1, related to a stretching mode inside the phosphate group of DNA, is very sensitive to the proton beam exposure, even at the lowest investigated dose. Therefore, it could be considered as a spectral marker of cytogenetic damage. Conclusions: The obtained results are encouraging for the future of Raman spectroscopy in radiobiology research, particularly for improving risk assessment in the field of proton radiotherapy. Specifically, these findings validate Raman spectroscopy to measure biological response in human breast cells exposed to standard proton therapy doses used in clinical setting. [ABSTRACT FROM AUTHOR]