A549, a commercially available cell line derived from primary lung cancer, was obtained from the American Type Culture Collection (ATCC, Rockville, MD). The present work describes an in vitro irradiation system for radiobiological experiments that closely resembles clinical conditions and overcomes problems relating to spheroid irradiation under sterile conditions.ĬAEP cells, derived from a squamous carcinoma of the lung, were isolated and established in our laboratory, as previously described. Indeed, the potential of three-dimensional (3-D) cell cultures for new anti-cancer therapeutic strategies is gaining recognition and is believed to improve the pre-animal and pre-clinical selection of the most promising treatment modalities. Multicellular tumor spheroids (MCTS) have a three-dimensional architectural organization in which the tumor cells are not uniformly exposed to nutrients and oxygen, a condition that closely mimics the organization of human tumors. It is also crucial for scientists working in this specific research area to carry out experiments on in vitro biological models that are capable of reproducing and mimicking clinical conditions.Īlthough human tumor cell lines grown in monolayer are mainly used for research and provide important information on basic tumor biology and radiobiology, they cannot be considered as fully representative of clinical tumors. Such studies are key to obtaining information on potential molecular targets for the setting up of novel radiosensitization approaches or for the design of mathematical algorithms suitable for tailoring radiotherapy. In recent years, researchers have focused on molecular mechanisms triggered by irradiation which could help cells to escape death. The principal task of radiobiology is to analyze the effects that may occur in the weeks, months and years after radiotherapy and propose improvements to current therapies. The irradiation of any biological system generates a succession of processes that can be grouped into physical, physical-chemical and biological phases, all characterized by specific events occurring at different times. This irradiation system, coupled with 3-D cell cultures, has the potential to generate information that could be used to individually tailor radiotherapy.
We set up a system for the irradiation, under sterile conditions, of tumor cells grown in 3-D which allows for the use of the same dose intensities and schedules utilized in clinical practice.
#Black body radiation experiment pdf to jpg plus
Finally, the 20 Gy dose did not affect cell survival in monolayer CAEP and A549 cells, whereas cisplatin or cisplatin plus radiation caused 100% cell death, regardless of the type of cell line used. Conversely, the effect of the radio- chemotherapy combination in A549-derived MCTS was similar to that induced by cisplatin or irradiation alone. Our preliminary results indicated a significant increment in radiotoxicity 20 days after the end of irradiation in the CAEP spheroids pre-treated with cisplatin compared to those treated with cisplatin or irradiation alone. We also tested the same treatment schemes on monolayer CAEP and A549 cells. The system was used to irradiate CAEP- and A549-derived MCTS, pre-treated or not with 20 μM cisplatin, with a dose of 20 Gy delivered in one session. To mimic the passage of radiation beams through human tissues before they reach the target tumor mass, 96-multiwell plates containing the multicellular tumor spheroids (MCTS) are inserted into a custom-built phantom made of plexiglass, the material most similar to water, the main component of human tissue. The system exploits the same equipment as that used for patient treatments, without the need for dedicated and highly expensive instruments. We developed a novel system for the irradiation, under sterile conditions, of 3-D tumor spheroids, the in vitro model considered as a bridge between the complex architectural organization of in vivo tumors and the very simple one of in vitro monolayer cell cultures. In particular, new models reproducing clinical conditions as closely as possible are needed for radiobiological studies to provide information that can be translated from bench to bedside. Although two-dimensional (2-D) monolayer cell cultures provide important information on basic tumor biology and radiobiology, they are not representative of the complexity of three-dimensional (3-D) solid tumors.
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