Cytokinesis-Block Micronucleus (Cbmn) Assay/CBMN Cytome Assay in Human Lymphocytes After in Vitro Irradiation and Its Use in Biodosimetry

Abstract

SummaryAim: Cytokinesis-block micronucleus (CBMN) assay and its comprehensive variant CBMN cytome assay are cytogenetic methods. CBMN is based on assessment of micronuclei in nucleated cells that have completed only one nuclear division. Besides micronuclei, CBMN cytome assay analyzes additional genotoxic (nucleoplasmic bridges and nuclear buds), cytostatic (nuclear division index), and cytotoxic (amount of necrotic and apoptotic cells) parameters. The aim of this study is to evaluate these parameters in human blood lymphocytes after in vitro irradiation and to assess its contribution to biodosimetry. Material and methods: Human blood from 6 donors was in vitro irradiated by 0, 1, 2, 3, 4, or 5 Gy and cultivated for 72 hours. Blood lymphocytes were stimulated with phytohemagglutinin and their cytokinesis was blocked by cytochalasin B. After cultivation, cultures were hypotonically treated, dropped onto glass slides and stained with Giemsa. Slides were evaluated by microscope. Results: We observed significantly increased amount of micronuclei, nucleoplasmic bridges, and nuclear buds measured in binucleated cells, significantly increased amount of micronuclei measured in mononucleated cells and significantly decreased nuclear division index after irradiation by 1, 2, 3, 4, and 5 Gy. Amount of death cells (apoptotic and necrotic) significantly increased after irradiation by 4 and 5 Gy. Conclusion: Although all parameters assessed by CBMN cytome assay have biodosimetric potential, practically feasible is only evaluation of micronuclei in binucleated cells. This parameter was used to construct in vitro linear-quadratic dose-response calibration curve which could be used as a biodosimetric tool for triage of radiation casualties.

Low levels of ionizing radiation exposure and cytogenetic effects in radiopharmacists

“…Our results showed a signifi cant decrease in the NDI values of radiation workers compared with non-exposed individuals (p> 0.0005), that could be due to the chronic low dose exposure. Signifi cant decrease in the pooled NDI values with increasing radiation doses was also observed by other studies (Antunes et al, 2014, Pejchal et al, 2011, IAEA, 2001.…”

Comparing Lymphocyte Radiosensitivity of Prostate Cancer Patients with Healthy Donors using Micronuclei and Chemical Premature Chromosome Condensation Tests

“…There was a significant difference between the MN yields at all of the radiation doses within each group in our study. If we were able to use FISH (Fluorescence In Situ Hybridization) technique for staining the MN slides, we could have scored the micronuclei with and without centromere from which scoring such micronuclei separately and their proportion might have helped to discriminate the healthy individuals and prostate cancer patients more accurately [ 33 ]. Regarding the NDI, this index is useful for cell cycle kinetic investigation and is an indicator for determining the defects that occur in cells after the mutagens like ionizing radiation.…”

Индуцирана От Йонизиращи Лъчения Геномна Нестабилност И Възможна Превенция Срещу Развитието На Остри Радиационни Поражения Или Късни Стохастични Ефекти

“…Микронуклеусите имат кръгла или овална форма, нямат свързващ мост или обща част с основното ядро. Интензитетът на оцветяване с 4% Гимза е сравнително еднакъв с основното ядро, но понякога може да бъде поголям или по-малък [12]. Бяха стриктно спазени специалните изисквания одобрени от международната агенция за атомна енергия (МААЕ, на англ.…”