ABSTRACT
ABSTRACT Albumin protein profiles were investigated in electrophoresis system in relation to the whole body exposition to the radiation. Two groups of rats Wistar were set up as the control (CG) and the irradiated one (IG). The IG was exposed to Co-60 at a dose of 5 Gy. After a 72-hour exposition, 300 μL of blood was collected in the inferior vena cava, renal, jugular, hepatic, and pulmonary veins and the serum separated. The albumin protein was identified by vertical electrophoresis in acrylamide Commassi blue or silver stained. The calibration procedure was applied to albumin samples with well-known concentrations. The mathematical correlation was developed involving electrophoretic parameters of band intensities and sizes from gel representation, providing values of protein concentrations in comparison with standard bands with known concentrations. There were significant differences in the physiological concentrations in the jugular and pulmonary sites in relation to renal and cava regional sites. Significant differences induced by radiation in serum albumin concentration were also found in hepatic and jugular sites. Alteration of albumin concentration was found as a nearly effect from whole body irradiation. This phenomenon points out to alterations in cell metabolism in the liver justified by a possible indication of proteomics damage from radiation.
ABSTRACT
Abstract Objective: In the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy. Materials and Methods: The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min–1 and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed. Results: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48–72 hours post-radiation. Conclusion: Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer. .
Resumo Objetivo: Neste estudo foi investigado o comportamento in vitro de linhagem de adenocarcinoma mamário (MDA-MB-231), radiorresistente, e de células mononucleadas do sangue periférico (PBMC) frente a diferentes doses de radiação, taxas de dose e cinética de tempo pós-irradiação, considerando o interesse para a radioterapia clínica. Materiais e Métodos: As linhagens foram irradiadas com Co-60, com 2 e 10 Gy, em duas taxas de exposição distintas, 339,56 cGy.min–1 e um quarto da primeira, presentes em um período de 10 anos da cobaltoterapia, respectivamente. Coletas pós-irradiação foram realizadas em cinética pré-estabelecida de 24, 48 e 72 horas. Avaliou-se a resposta da densidade óptica em ensaio de viabilidade e foi feita uma análise morfológica. Resultados: Células PBMC, sensíveis à radiação, apresentaram diminuição da viabilidade a 2 Gy e fortemente a 10 Gy em ambas as taxas de dose. Células MDA-MB-231 apresentaram diminuição da viabilidade apenas com dose e taxa de doses elevadas. Os resultados também demonstraram expansão clonal de MDA-MB-231 em baixa dose e taxa de dose pós 48–72 horas pós-irradiação. Conclusão: Baixa taxa de dose apresenta possível impacto clínico de redução do controle tumoral de linhagens radiorresistentes em câncer de mama em cobaltoterapia. .