Indiana University-Purdue University Indianapolis (IUPUI) / Studies performed by our lab have investigated the potential radioprotective effect of rDEK protein. Although roles played by DEK in cell differentiation, DNA repair, DNA binding, chromatin regulating and different malignancies have been investigated previously in different cell types, the prospect of DEK being used as a potential radioprotective agent for HSCs has not yet been explored. In this study, using primary cells isolated from bone marrow of C57BL/6 mice in vitro, our data indicated that rDEK has the ability to act as potential radioprotector of HSC. Moreover, a significant decrease in percentages of caspase-3 and caspase-9 protease enzymes was observed after irradiation in presence of rDEK. Taken, together the data suggests that DEK imparts its effect as a potential radioprotective agent, via inhibiting the caspase-dependent intrinsic apoptosis pathway. We found no evidence that DEK could act as a radiomitigator but this was not tested in primary cells as well as in animals.

Amifostine (WR-2721, delivered as Ethyol) is a radioprotector agent that reduces the likelihood of early and/or late biological effects by eliminating free radical particles during ionizing radiation fraction (radiotherapy). It activates in under normal tissues conditions to reduce mutation and fraction in DNA. Among 4000 prodrug compounds, amifostine is the only agent has been approved from the US Food and Drug Administration in clinical purposes. The main effective mechanisms of amifostine are based on scavenging for free radical, improving for DNA repair step and indication of cellular hypoxia. In the same time, this drug is not widely used around the world for different reasons mainly its high cost and toxicity level (lethal dose). Conjugating a monoclonal antibody with amifostine by a suitable linker is a process of Antibody Drug Conjugate producing immuno-radioprotector molecule hypothesis. Administrated molecule is an approach of targeted delivery therapy that increases the dosage uptake into particular area of treatment to minimize the dose distribution in non-targeted area in the body. In the present work, we proposed a three-compartment system model to simulate the two-pore theory pathway of an immuno-radioprotector molecule when it is crossing the physiological barriers. The model investigated its distribution and elimination in porous media (with both large and small pores) within a pharmacokinetics compartmented model approach.

The clinical consequences of ionizing radiation exposure remain one of the leading causes of death in the United States. Much research has been carried out to discover a potential countermeasure for acute radiation syndrome (ARS) without success. The United States Food and Drug Administration (US FDA) has not accepted any effective and harmless ionizing radiation therapy agents (radioprotectors) for treating ARS. It has recently been discovered that g-tocotrienol (GT-3), one of the E vitamers chiefly present in palm oil, has radioprotective abilities in mice and nonhuman primate (NHP) models. Though GT-3 is one of the most promising countermeasures discovered, the separation and purification from other vitamers or its matrix is difficult. This has limited its characterization, derivatization, and biomedical application. We have therefore designed novel chromatographic methods to optimize separation and purification. Thin layer chromatography (TLC) was used to ascertain the best solvent system for column chromatography (CC). Exactly 8% ethyl acetate in hexane employed in TLC and CC resulted in good separation (Rf ≥ 0.3) and purification. Various fractions presumed to contain GT-3 were collected and analyzed to confirm the exact structure using 1H NMR, 13C NMR, DEPT, and GC-MS. Results obtained so far have revealed the exact structure of the compound. However, some traces of impurities have been indicated by the NMR outcomes; therefore, high-performance liquid chromatography (HPLC) will be used to maximize GT-3 purification. This present study will be instrumental in elucidating the biochemical structure of various complex plant bioactive components that are hard to isolate and analyze. It is envisioned that this work will help to erase the knowledge deficit in medicinal chemistry and assist in the development of new medications for ARS.

Au moins 60% des patients atteints de cancer vont recevoir de la radiothérapie (RT). L’efficacité de la radiothérapie dans le traitement du cancer est limitée par le phénomène de radiorésistance des cellules cancéreuses et par la toxicité des radiations sur les tissus sains. La découverte de nouveaux agents radiosensibilisants et radioprotecteurs permettrait de surmonter ces difficultés. Les modèles cellulaires 3D tels que les sphéroïdes, émergent motivés par le besoin de modèles précliniques plus proches des tumeurs in vivo. L’objectif du projet est d’optimiser un système microfluidique pour tester facilement et à faible coût des agents thérapeutiques avec la RT sur des sphéroïdes dans un contexte de repositionnement. Le système microfluidique développé permet la formation de 336 sphéroïdes homogènes en deux jours avec intervention minimale de l’utilisateur. Les sphéroïdes sont répartis dans 16 chambres de culture séparées par un système de valve magnétique pour éviter des effets bystander entre sphéroïdes irradiés et non-irradiés. Une nouvelle technique d’irradiation a été développée permettant d’exposer un système à 4 doses de radiation différentes. En tout, 4 doses de radiation et 4 concentrations d’agents thérapeutiques peuvent être testées par système. En utilisant cette approche, l’efficacité de trois agents avec la RT a été évaluée avec des tests de survie clonogénique. Nous avons démontré que le Talazoparib, un inhibiteur de PARP, radiosensibilise les cellules de sarcome de tissus mous (STS) cultivés en sphéroïdes à 2 Gy. Le système développé permet d’évaluer le potentiel d’agents thérapeutiques avec la RT et contribue à l’adoption des sphéroïdes comme modèle préclinique. / At least 60% of cancer patients will receive radiotherapy (RT) as part of their treatment. The efficacy of radiotherapy in the treatment of cancer is limited by the phenomenon of radioresistance of cancer cells and by the toxicity of radiation on healthy tissues. The discovery of new radiosensitizers and radioprotectors is essential to overcome these challenges. 3D cellular models such as spheroids emerge motivated by the need for better preclinical models. The objective of the project was to optimize a microfluidic system for easy, fast and low-cost testing of therapeutic agents with RT on spheroids. The developed microfluidic system allows the formation of 336 homogeneous spheroids in two days with minimal user intervention. The spheroids are distributed in 16 culture chambers separated by a magnetic valve system to avoid bystander effects between irradiated and unirradiated spheroids. A new irradiation technique has been developed to expose a system with 4 different radiation doses. In total, 4 radiation doses and 4 concentrations of therapeutic agents can be tested per system. Using this approach, the efficacy of three agents with RT was evaluated with clonogenic assays. Radiosensitizing properties of Talazoparib, a PARP inhibitor, on soft tissue sarcoma (STS) cells cultured as spheroids at 2 Gy were demonstrated. The developed system enables the evaluation of therapeutic agents with RT and contributes to the wide adoption of spheroids as a preclinical model.