Radiation Carcinogenesis: Tissue Culture Model
Kedar N. Prasad in Handbook of RADIOBIOLOGY, 2020
Based on numerous cellular and molecular biology studies, the following hypotheses of cancer have been proposed: Activation of protooncogenes.3,4Loss of antioncogenes.5Infection with certain viruses.6Substitution of normal promoters of protooncogenes with strong promoters of viruses.7Chromosomal aberrations.8b
Synergistic Combinations of Hyperthermia and Inhibitors of Nucleic Acids and Protein Synthesis
Leopold J. Anghileri, Jacques Robert in Hyperthermia In Cancer Treatment, 2019
The bleomycins are copper-chelating basic glycopeptides isolated as fermentation products of Streptomyces verticillus. The most likely mechanism of cytotoxic action of the bleomycins is probably due to their property of inducing chain scission and fragmentation of DNA molecules. In addition, chromosomal aberrations have been noted which may have been caused by the damaged DNA. The scission of DNA seems to be due to the interaction of bleomycin with O2 and Fe2+. The reaction is postulated to involve the oxidation of the DNA-bound Fe2+-bleomycin complex to a Fe3+-bleomycin complex which is able to dissociate from the DNA, be reduced, and react again with DNA. Each cycle may release one purine or pyrimidine base.61
Fenugreek in Management of Female-Specific Health Conditions
Dilip Ghosh, Prasad Thakurdesai in Fenugreek, 2022
For regulatory purposes, a chemical’s mutagenicity potential has mainly been evaluated using in vitro assays, such as the Bacterial Reverse Mutation Test, AMES test (Mortelmans and Zeiger 2000). Mutagens are agents that can cause heritable changes in DNA, and their capacity to cause mutations is defined as mutagenicity (Cvetković, Takić Miladinov, and Stojanović 2018). As all information for the proper development, functioning, and reproduction of organisms is coded in DNA, mutations can result in harmful effects and play a role in genetic disorders (Verheyen 2017), especially for food-related products (Mandal et al. 2018; Weisburger 1999). The structural chromosomal abnormalities such as chromosomal aberration (a missing, extra, or irregular portion of chromosomal DNA) result from breakage and incorrect rejoining of chromosomal segments and result in many genetic diseases disorders such as cancer (Nguyen 2020). The standardized fenugreek seed extracts with markers such as furostenol saponins, glycosides, or low molecular galactomannans such as FENU-FG, SFSE-G, and LMWGAL-TF, were found safe and devoid of mutagenicity (OECD Test No. 471) and genotoxicity (Mammalian Chromosomal Aberration, OECD Test No. 473) potential during these studies (Deshpande, Mohan, and Thakurdesai 2016a; Deshpande, Mohan, Ingavale et al. 2017).
Oxidative protein modification and chromosomal instability among type 2 diabetics in Osogbo, Nigeria
Published in Alexandria Journal of Medicine, 2021
O.O. Olaniyan, O.O Odewusi, H.B Osadolor
Due to increased relative risk of morbidity and mortality among individuals with diabetes as compared with apparently healthy non-diabetes controls, diabetes can be viewed as a premature aging syndrome that affects the overall metabolic shift leading to genotoxic stress and loss of chromosomal integrity [8]. Alterations in genomic system occur when the process of oxidative DNA lesions/damage overwhelms the DNA repair mechanism, leading to accumulation of unrepaired damaged DNA in the system. Thus, chromosomal aberration can be described as the microscopically visible part of a wide spectrum of DNA changes generated by different repair mechanisms of DNA double strand breaks and it represents the biological consequences of human exposure to either ionizing or genotoxic agents or both [9]. Chromosomal aberrations can either be a numerical abnormalities (missing of whole chromosome or addition of extra chromosome to the normal pair) or structural abnormalities (when part of an individual chromosome is missing/extra switched to another chromosome/turned upside down) [10]. Structural chromosomal aberration (sCA) is a product of breakage and incorrect rejoining of chromosomal segments that resulting in varieties of disease conditions. Structural chromosomal aberration can either be balanced (the complete chromosomal set is still present after being rearranged, e.g. inversions, translocations) or unbalanced (after the rearrangement the complete chromosomal set is either missing or having an addition, e.g. deletions, duplications, insertions) [11].
Role of inflammation in the malignant transformation of pleural mesothelial cells induced by multi-walled carbon nanotubes
Published in Nanotoxicology, 2020
Xiaopei Huang, Yijun Tian, Wenjing Shi, Jikuai Chen, Lang Yan, Lijun Ren, Xiaofang Zhang, Jiangbo Zhu
The genotoxicity of MWCNTs on macrophages and Met 5A cells was detected using a chromosome aberration assay. The groups were as follows: positive control group cyclophosphamide + Met 5A) and negative control group (DMSO + Met 5A). The other groups were: macrophages + Met 5A; MWCNTs + Met 5A; MWCNTs + macrophages + Met 5A. The final concentration of MWCNTs was 0.1 µg/mL with an exposure time of three months. Results demonstrated that chromosomal aberrations in the negative control group, positive control group, macrophages + Met 5A group, MWCNTs + Met 5A group, and MWCNTs + macrophages + Met 5A group were 1.0, 14.6, 0.8, 2.8, and 5.0%, respectively. Compared to the negative control group, the chromosome aberration rate of the MWCNTs + macrophages + Met 5A group and the MWCNTs + Met 5A group increased significantly (p < 0.05). Similarly, compared to the MWCNTs + Met 5A group, the chromosome aberration rate of the MWCNTs + macrophages + Met 5A group increased significantly (p < 0.05) (Table 3). The types of chromosomal aberrations are mainly breakage, chromosomal ring, triploidy, polyploidy, and so forth. Typical pictures depicting normal and aberrant chromosomes are shown in Figure 3.
Interaction of L-ascorbic acid and α-tocopherol in alleviating 1, 4-benzoquinone, a metabolite of benzene induced genotoxicity in male Wistar rats
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Ritu Mishra, Karabi Dutta, Manuj Kr. Bharali
The chromosomal aberration analysis of bone marrow cells of animals treated with BQ revealed significant (p < 0.05) increase in the number and percentage of aberrant cells when compared to the control group (Table 2). Chromatid and chromosomal gaps, breaks and deletion were found to be the prominent type of chromosomal aberrations in the present study (Figure 1b–f). The highest percentage of chromosomal aberrations (94.50%) was recorded after 24 h which decreased considerably after 48 h (92.13%) and 72 h (91.48%) of BQ treatment (Table 2). However, coadministration of L-ascorbic acid and/or α-tocopherol with BQ significantly reduced the frequency of abnormal metaphases as compared to only BQ treated animals (Table 2). L-ascorbic acid cotreatment inhibited BQ induced clastogenecity by 60.26%, 39.63% and 40.05% at 24 h, 48 h or 72 h post treatments whereas α-tocopherol was found to inhibit BQ-induced chromosomal damage by 77.42%, 69.94% and 72.56% at 24 h, 48 h and 72 h post treatments respectively (Table 2). Co-administration of L-ascorbic acid and α-tocopherol were able to inhibit BQ induced frequency of clastogenecity by 90.02%, 88.40% and 94.46% following 24 h, 48 h and 72 hr post treatments respectively (Table 2).
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