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Anaplastic thyroid cancer (ATC) is of the most aggressive thyroid cancer. While ATC is rare, it accounts for a disproportionately high number of thyroid cancer-related deaths. Here, we developed an ATC xenotransplant model in zebrafish larvae, where we can study tumorigenesis and therapeutic response in vivo. Using both mouse (T4888M) and human (C643)-derived fluorescently labeled ATC cell lines, we show these cell lines display different engraftment rates, mass volume, proliferation, cell death, angiogenic potential, and neutrophil and macrophage recruitment and infiltration. Next, using a PIP-FUCCI reporter to track proliferation in vivo, we observed cells in each phase of the cell cycle. Additionally, we performed long-term non-invasive intravital microscopy over 48 h to understand cellular dynamics in the tumor microenvironment at the single-cell level. Lastly, we tested two drug treatments, AZD2014 and a combination therapy of dabrafenib and trametinib, to show our model could be used as an effective screening platform for new therapeutic compounds for ATC. Altogether, we show that zebrafish xenotransplants make a great model to study thyroid carcinogenesis and the tumor microenvironment, while also being a suitable model to test new therapeutics in vivo. [ABSTRACT FROM AUTHOR]

• Flow cytometry display individual nuclear alteration in erythrocytes of tilapia. • Nuclear alteration is accompanied by cell repair blockage caused by cadmium. • Flow cytometry is sensitive to genotoxicity detection. • Use of flow cytometer to detect polluted aquatic environments. Morphological nuclear alterations are indicative of DNA damage and have been considered excellent markers of exposure to several pollutants in aquatic environments. Flow cytometry is a powerful technique for measuring cell phenotypes in large numbers of cells in a short period of time. This technique is suited to the study of cell populations and subset identification as a function of its high-throughput and multi-parameter characteristics. We used the quantification of erythrocyte nuclear alterations to compare the techniques of imaging flow cytometry and light microscopy. The comparison used blood samples of the fish Oreochromis niloticus assayed using cadmium as a nuclear alteration-inducing agent. The results showed that imaging flow cytometry has higher sensitivity than light microscopy for detecting and quantifying erythrocytic nuclear alterations. We conclude that imaging flow cytometry can produce fast and reliable results and could potentially be useful in studies involving fish erythrocytes under normal and impacted environmental conditions. [ABSTRACT FROM AUTHOR]

In order to understand events and mechanisms present in the pathophysiology of tilapia's chronic inflammation and based on the immunomodulatory activity attributed to cyclophosphamide which is widely used to suppress immune responses in human medicine, the present study investigated the effects of cyclophosphamide (CYP) treatment on the modulation of foreign body inflammatory reaction in Nile tilapia (Oreochromis niloticus) with round glass coverslip implanted in the subcutaneous tissue (9 mm of diameter). Forty tilapia (151 ± 10,2 g) were randomly distributed in 5 aquariums (n = 8) with a capacity of 250 L of water each, to compose two treatments (sampled 3 and 6 days post-implantation): implanted/untreated (control) and implanted/treated with 200 mg of CYP kg−1 of b.w., through i.p. route. A fifth group (n = 8) was sampled without any stimulus (naive) to obtain reference values. CYP-treated tilapia showed decrease in macrophage accumulation, giant cell formation and Langhans cells on the glass coverslip when compared to control fish. The treatment with CYP resulted in decrease of leukocyte and thrombocyte counts. Decrease in alpha-2-macroglobulin, ceruloplasmin, albumin and transferrin levels, as well as increase in haptoglobin, complement C3 and apolipoprotein A1 were observed in tilapias during foreign body inflammation. Blood levels of complement C3, alpha-2-macroglobulin, ceruloplasmin and transferrin were modulated by treatment with CYP. Therefore, the treatment with 200 mg of CYP kg−1 of b.w. in tilapia resulted in an anti-inflammatory effect by suppressing the dynamics between leukocytes in the bloodstream and macrophage accumulation with giant cell formation in the inflamed focus, as well as by modulating APPs during foreign body reaction. Image 1 • Anti-inflammatory effect was observed in CYP-treated tilapia. • Tilapia presented modulation of APPs during foreign body reaction. • Treatment with CYP suppressed macrophage accumulation and polykarion formation. • Tilapia treated with CYP showed decrease of leukocyte and thrombocyte counts. • Alpha-2-macroglobulin, ceruloplasmin and transferrin were modulated by CYP. [ABSTRACT FROM AUTHOR]

• SARS-CoV-2 peptides were able to induce anxiety-like behavior in P. reticulata. • SARS-CoV-2 peptides increased acetylcholinesterase (AChE) activity in guppy. • Exposure to SARS-CoV-2 peptides affected growth and development of guppies. • REDOX imbalance was observed in guppies exposed to SARS-CoV-2 peptides. There have been significant impacts of the current COVID-19 pandemic on society including high health and economic costs. However, little is known about the potential ecological risks of this virus despite its presence in freshwater systems. In this study, we aimed to evaluate the exposure of Poecilia reticulata juveniles to two peptides derived from Spike protein of SARS-CoV-2, which was synthesized in the laboratory (named PSPD-2002 and PSPD-2003). For this, the animals were exposed for 35 days to the peptides at a concentration of 40 µg/L and different toxicity biomarkers were assessed. Our data indicated that the peptides were able to induce anxiety-like behavior in the open field test and increased acetylcholinesterase (AChE) activity. The biometric evaluation also revealed that the animals exposed to the peptides displayed alterations in the pattern of growth/development. Furthermore, the increased activity of superoxide dismutase (SOD) and catalase (CAT) enzymes were accompanied by increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and hydrogen peroxide (H 2 O 2), which suggests a redox imbalance induced by SARS-CoV-2 spike protein peptides. Moreover, molecular docking analysis suggested a strong interaction of the peptides with the enzymes AChE, SOD and CAT, allowing us to infer that the observed effects are related to the direct action of the peptides on the functionality of these enzymes. Consequently, our study provided evidence that the presence of SARS-CoV-2 viral particles in the freshwater ecosystems offer a health risk to fish and other aquatic organisms. [Display omitted] [ABSTRACT FROM AUTHOR]