N-methyl-N-nitrosourea induces zebrafish anomalous angiogenesis through Wnt/β-catenin pathway

Stereo-selective cardiac toxicity induced by metconazole via oxidative stress and the wnt/β-catenin signaling pathway in zebrafish embryos

Metconazole (MEZ), a chiral triazole fungicide, produces enantioselective adverse effects in non-target organisms. Among MEZ's isomers, cis-MEZ displays robust antimicrobial properties. Evaluating MEZ and cis-MEZ's toxicity may mitigate fungicide usage and safeguard non-target organisms. Our study evaluated the toxicity of MEZ and its cis-isomers at concentrations of 0.02, 0.2, 2, and 4 mg L-1. We report stereoselectivity and severe cardiovascular defects in zebrafish, including pericardial oedema, decreased heart rate, increased sinus venous and bulbous arteries distances, intersegmental vessel defects, and altered cardiovascular development genes (hand2, gata4, nkx2.5, tbx5, vmhc, amhc, dll4, vegfaa, and vegfc). Further, MEZ significantly increased oxidative stress and apoptosis in zebrafish, primarily in the cardiac region. Isoquercetin, an antioxidant found in plants, partially mitigates MEZ-induced cardiac defects. Furthermore, MEZ upregulated the Wnt/β-catenin pathway genes (wnt3, β-catenin, axin2, and gsk-3β) and β-catenin protein expression. Inhibitor of Wnt Response-1 (IWR-1) rescued MEZ-induced cardiotoxicity. Our findings highlight oxidative stress, altered cardiovascular development genes, and upregulated Wnt/β-catenin signaling as contributors to cardiovascular toxicity in response to MEZ and cis-MEZ treatments. Importantly, 1R,5S-MEZ exhibited greater cardiotoxicity than 1S,5R-MEZ. Thus, our study provides a comprehensive understanding of cis-MEZ's cardiovascular toxicity in aquatic life.

YTHDF1 mediates N-methyl-N-nitrosourea-induced gastric carcinogenesis by controlling HSPH1 translation

YT521-B homology (YTH) domain family (YTHDF) proteins serve as readers that directly recognise m6A modifications. In this study, we aim to probe the role of YTHDF1 in environmental carcinogen-induced malignant transformation of gastric cells and gastric cancer (GC) carcinogenesis. We established a long-term low-dose MNU-induced malignant transformation model in gastric epithelial cells. In vivo and in vitro experiments were conducted to validate the malignant phenotype and characterise the roles of YTHDF1 and its downstream genes in malignant transformation cells. Additionally, we explored downstream m6A modification targets of YTHDF1 using RNA-sequencing, RNA immunoprecipitation, and proteomics analyses, and conducted validation experiments in cell experiments and clinical samples. Long-term low-dose exposure of MNU converted normal Gges-1 cells into malignant cells. YTHDF1 mRNA and protein expression are increased in MNU-induced malignant cells (p<0.001). Meanwhile, YTHDF1 knockdown inhibits the malignant potential of MNU-treated cells (p<0.01). YTHDF1 knockdown specifically suppresses HSPH1 protein, but not RNA levels. RIP-qPCR validates HSPH1 is the target of YTHDF1 (p<0.01). HSPH1 knockdown impairs the malignant potential of MNU-induced transformed cells. The increased expression of the key regulatory factor YTHDF1 in MNU-induced gastric carcinogenesis affects malignant transformation and tumorigenesis by regulating the translation of downstream HSPH1. These findings provide new potential targets for preventing and treating environmental chemical-induced gastric carcinogenesis.

Incorporating Primer Amplification Efficiencies in Quantitative Reverse Transcription Polymerase Chain Reaction Experiments; Considerations for Differential Gene Expression Analyses in Zebrafish

Quantitative reverse transcription polymerase chain reaction (RT-qPCR) is commonly used to measure the mRNA expression of target genes in zebrafish. Gene expression values from RT-qPCR are typically reported as relative fold-changes, and relative quantification of RT-qPCR data incorporates primer amplification efficiency values for each target gene. We describe the influence of the primer amplification efficiency analysis method on RT-qPCR gene expression fold-change calculations. This report describes (1) a sample analysis demonstrating incorporation of primer amplification efficiency into RT-qPCR analysis for comparing gene expression of a gene of interest between two groups when normalized to multiple reference genes, (2) the influence of differences in primer amplification efficiencies between measured genes on gene expression differences calculated from theoretical delta-Cq (dCq) values, and (3) an empirical comparison of the influence of three methods of defining primer amplification efficiency in gene expression analyses (delta-delta-Cq [ddCq], standard curve, LinRegPCR) using mRNA measurements of a set of genes in zebrafish embryonic development. Given the need to account for the influence of primer amplification efficiency along with the simplicity of using software programs (LinRegPCR) to measure primer amplification efficiency from RT-qPCR data, we encourage using empirical measurements of primer amplification efficiency for RT-qPCR analysis of differential gene expression in zebrafish.

Pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor increases the efficacy of cabazitaxel by inducing apoptosis and decreasing cancer stem cells

Cancer stem cells (CSCs) are associated with metastasis and recurrence in prostate cancer as well as other cancers. We aimed to enhance the sensitivity of cabazitaxel in prostate cancer cell therapy by targeting CSCs with a Wnt inhibitor and salinomycin pretreatment. PC3, DU-145, and LNCaP human prostate cancer cells were exposed to Wnt/β-catenin pathway inhibitor CCT036477 (iWnt) with salinomycin for 48 h, followed by cabazitaxel treatment for 48 h. Cell viability, mRNA, and protein expression changes were evaluated by MTT, RT-qPCR, and Western blot assays, respectively. Apoptosis was determined by image-based cytometry, and cell migration was assessed by wound healing assay. Three-dimensional culture was established to assess the malignant phenotype and stemness potential of transformed or cancer cells. CD44 + CSCs were isolated using magnetic-activated cell sorting system. Pretreatment of PC3, DU-145, and LNCaP cells with salinomycin iWnt significantly sensitized the cells to cabazitaxel therapy. Spheroid culture confirmed that the treatment modality was more effective than a single administration of chemotherapy. The pretreatment of PC3 cells increased the rate of apoptosis compared to single administration of cabazitaxel, which downregulated Bcl-2 and upregulated caspase 3, caspase 8 expressions. The pretreatment suppressed cell migration, downregulated the expression of Sox2 and Nanog, and significantly reduced CD44 + CSC numbers. Notably, the treatment modality reduced pAKT, p-P38 MAPK, and pERK1/2. The data suggest that pretreatment of prostate cancer cells with salinomycin and Wnt inhibitor may increase the efficacy of cabazitaxel therapy by inhibiting cell proliferation and migration, and eliminating cancer stem cells.