Evaluation of Proton-Induced Biomolecular Changes in MCF-10A Breast Cells by Means of FT-IR Microspectroscopy

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

Array of time-of-flight diamond detectors for particle discrimination in laser driven p-11B fusion experiments

The detection of radiation emission in laser induced plasma experiments is an helpful method for gaining information on the physics of laser-matter interaction. Time-of-Flight (TOF) approach is a powerful and effective method to obtain timely spectra of particles accelerated from laser-generated plasma. To this respect, diamond-based detectors are very attractive due to their interesting features such as fast signal collection time, signal proportional to the energy deposited by the incident radiation, blindness to visible radiation, high radiation hardness and low leakage current at room temperature operation. Unfortunately, they cannot supply discrimination on the species of the incoming ions, but only their energies. This may be overcome using specific filtering foils to exploit the different stopping powers of ions of different species and energies. In this work we describe the method to distinguish particles using an array of TOF diamond detectors. A first prototype array, consisting of 2×2 diamond detectors, nominally identical and featuring by aluminum filters of different thicknesses, was developed and preliminary tested at PALS facility in Prague

Analysis of radiation-induced DNA double strand breaks after exposure to alpha particles: γ-H2AX staining method

The aim of this study was to analyse the γ-H2AX foci in HTB177 non-small lung cancer cells after irradiation with helium ions. Cells were irradiated in three different positions along the widened Bragg peak to follow formation of DNA DSB with respect to LET values. To compare diverse approaches in γ-H2AX foci analysis, we applied the method of foci quantification and total fluorescence intensity measurements. It was shown that helium ions significantly increased the number of γ- H2AX in all irradiated cells. Somewhat higher number of foci was found in samples irradiated within the LET of 24 keV/μm than in those exposed to 4.8 and 37 keV/μm. The same trend was observed after γ-H2AX total fluorescence analysis, showing a good correlation with the results of γ- H2AX foci counting. Further analysis of foci size, as well as colocalization with other DSB repair factors would complement these analyses and give more information about the nature of DNA lesions induced by helium ions

Direct and indirect effects of proton and carbon ion irradiations on breast adenocarcinoma cells

ERRS 2022, 47th Annual Meeting of the European Radiation Research Society; 21-24 September 2022, Catania, Italy

Proton therapy and src family kinase inhibitor combined treatments on U87 human glioblastoma multiforme cell line

Glioblastoma Multiforme (GBM) is the most common of malignant gliomas in adults with an exiguous life expectancy. Standard treatments are not curative and the resistance to both chemotherapy and conventional radiotherapy (RT) plans is the main cause of GBM care failures. Proton therapy (PT) shows a ballistic precision and a higher dose conformity than conventional RT. In this study we investigated the radiosensitive effects of a new targeted compound, SRC inhibitor, named Si306, in combination with PT on the U87 glioblastoma cell line. Clonogenic survival assay, dose modifying factor calculation and linear-quadratic model were performed to evaluate radiosensitizing effects mediated by combination of the Si306 with PT. Gene expression profiling by microarray was also conducted after PT treatments alone or combined, to identify gene signatures as biomarkers of response to treatments. Our results indicate that the Si306 compound exhibits a radiosensitizing action on the U87 cells causing a synergic cytotoxic effect with PT. In addition, microarray data confirm the SRC role as the main Si306 target and highlights new genes modulated by the combined action of Si306 and PT. We suggest, the Si306 as a new candidate to treat GBM in combination with PT, overcoming resistance to conventional treatments

Radiobiological outcomes, microdosimetric evaluations and monte carlo predictions in eye proton therapy

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

Time of Flight based diagnostics for high energy laser driven ion beams

Nowadays the innovative high power laser-based ion acceleration technique is one of the most interesting challenges in particle acceleration field, showing attractive characteristics for future multidisciplinary applications, including medical ones. Nevertheless, peculiarities of optically accelerated ion beams make mandatory the development of proper transport, selection and diagnostics devices in order to deliver stable and controlled ion beams for multidisciplinary applications. This is the main purpose of the ELIMAIA (ELI Multidisciplinary Applications of laser-Ion Acceleration) beamline that will be realized and installed within 2018 at the ELI-Beamlines research center in the Czech Republic, where laser driven high energy ions, up to 60 MeV/n, will be available for users. In particular, a crucial role will be played by the on-line diagnostics system, recently developed in collaboration with INFN-LNS (Italy), consisting of TOF detectors, placed along the beamline (at different detection distances) to provide online monitoring of key characteristics of delivered beams, such as energy, fluence and ion species. In this contribution an overview on the ELIMAIA available ion diagnostics will be briefly given along with the preliminary results obtained during a test performed with high energy laser-driven proton beams accelerated at the VULCAN PW-laser available at RAL facility (U.K.)