N method. High-dosage levels of ascorbic acid (Vitamin C) have currently been shown to act as anti-cancer agent for various types of cancer [21]. Vitamin C can act as an antioxidant, lowering ROS levels, but it also can function as pro-oxidant to kill cancer cells in vitro and slow tumour growth in vivo. Pharmacologic levels of Vitamin C have been shown to aggravate the ROS-mediated toxicity in SDHBKD mouse phaeochromocytoma (MPC) cells, thus top to Azido-PEG6-NHS ester Autophagy genetic instability and apoptotic cell death [19]. In addition, these SDHBKD MPC cells have been injected into athymic nude mice, establishing metastatic PPGL tumours in vivo; the supplementation of high-dosage levels of Vitamin C strongly delayed metastatic lesions and thereby improved disease outcome [19]. Recently, we generated and characterised a systemic sdhbrmc200 knockout zebrafish model that mimics the metabolic properties of SDHB-associated PPGLs [22]. Homozygous sdhbrmc200 mutant larvae show a decreased lifespan on account of decreased mitochondrial complex II activity and substantial succinate accumulation, and they mimic vital genomic and metabolic effects observed in SDHB-associated PPGL tumours [22]. In addition, a decreased mobility attributed to energy deficiency is observed. These phenotypic read-outs in 6-day-old zebrafish larvae might be employed to evaluate the effects of candidate drugs and could facilitate the (semi) high-throughput in vivo testing of prospective therapeutic agents for SDHB-associated PPGLs. Within this study, we investigated redox homeostasis in larvae of your sdhbrmc200 zebrafish model, and we evaluated the impact of each low-dosage and high-dosage levels of Vitamin C by utilizing an in vivo zebrafish drug screen. two. Benefits 2.1. sdhbrmc200 Zebrafish Larvae as Drug Screening Model for SDHB-Associated PPGLs two.1.1. Homozygous sdhbrmc200 Zebrafish Larvae Brofaromine Autophagy Exhibit Improved Reactive Oxygen Species (ROS) Levels To investigate whether sdhbrmc200 larval zebrafish mutants possess an unbalanced cellular redox state, whole-mount ROS-detection was made use of to identify ROS levels at baseline. At day six post fertilization (dpf), increased levels of ROS have been observed in homozygous sdhb in comparison to their heterozygous sdhb and wild-type siblings (Figure 1).s 2021, 13, xCancers 2021, 13, x FOR PEER Evaluation FOR PEER REVIEW3 of3 ofCancers 2021, 13,three ofbaseline. At day six post fertilization (dpf), increased levels of ROS in homobaseline. At day six post fertilization (dpf), enhanced levels of ROS were observedwere observed in homozygous sdhb in comparison to their heterozygous sdhb siblings (Figure 1). zygous sdhb when compared with their heterozygous sdhb and wild-type and wild-type siblings (Figure 1).Figure 1. Reactive oxygen species (ROS) measurements showed a important enhance in homozyFigure 1. Reactive oxygen speciesoxygen measurements showed a considerable improve in homozy- in homozygous Figure 1. Reactive (ROS) species (ROS) measurements showed a substantial enhance gous 17) compared to their heterozygous (n = 22) and wild-type siblings (n = 12) at gous sdhb larvae (n =larvaelarvae (n in comparison with their heterozygous (n = 22) and wild-type siblings (n = 12) at 6 dpf. sdhb sdhb (n = 17) = 17) in comparison with their heterozygous (n = 22) and wild-type siblings (n = 12) at six dpf. One-way ANOVA with Tukey’s post0.001.p p 6 dpf. One-way One-way ANOVA withpost hoc post hocptest, test, 0.001. 0.001. ANOVA with Tukey’s Tukey’s test, hoc2.1.two. Thriving Design and style of Drug Screening Protocol 2.1.2. Drug Screening.
