Environmental cadmium-induced circRNA-miRNA-mRNA network regulatory mechanism in human normal liver cell model

At present, hundreds of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been confirmed to be related to the toxicity of cadmium (Cd). However, the role of circular RNAs (circRNAs) in the toxicity of Cd and the underlying regulatory mechanisms remain unclear. In this study, we chose human normal liver cells (L-02) as a model to investigate changes in transcriptome expression levels following exposure to Cd. Total RNA of each sample was extracted by Trizol method, and the expression profiles of circRNAs, miRNAs and mRNAs of each sample were determined by microarray hybridization and scanning. After standardizing the data, differential circRNAs, miRNAs, and mRNAs associated with the toxic effects of Cd were identified. By screening the predicted circRNAs, miRNAs, and mRNAs, we constructed a competing endogenous RNA (ceRNA) network, and predicted the main biological functions and metabolic pathways influenced by Cd toxicity. Our comprehensive screening strategy led to the identification of 266 different circRNAs, 223 different miRNAs and 519 different mRNAs exhibiting differential expression. Following further screening, even circRNAs, 10 miRNAs and 97 mRNAs were incorporated into the ceRNA network. After performing GO enrichment and KEGG pathway analyses on the 97 mRNAs within the ceRNA network, which indicated that the circRNAs in the ceRNA network are poised to modulate key cellular processes, including cell proliferation, apoptosis, oxidative stress and inflammatory responses under the toxic effects of Cd-induced damage in L-02 cells.