Screening and validation of nickel ion cytotoxicity biomarkers based on transcriptomic and proteomic technology

The aim of this study was to screen cytotoxicity biomarkers of nickel ions (Ni²⁺) using transcriptomic and proteomic approaches combined with molecular biology validation. First, the MTT method was used to evaluate cytotoxicity in L929 cells treated with Ni²⁺ at different concentrations. Ni²⁺ at both 100 μM and 200 μM affected cell proliferation. Then, transcriptomic and proteomic technology was used to study the effects of Ni²⁺ on the expression of genes/proteins in cells. It was found that 1490, 789, 652 and 729 genes (12, 24, 48 and 72 h, respectively) and 177, 2191 and 2095 proteins (12, 24 and 48 h, respectively) were differentially expressed after treatment with 100 μM Ni²⁺. In total, 1403, 963, 916 and 1230 genes (12, 24, 48 and 72 h, respectively) and 83, 1681 and 2398 proteins (12, 24 and 48 h, respectively) were differentially expressed after treatment with 200 μM Ni²⁺. Then, four target gene/protein biomarkers were filtered by combined screening using gene/proteomic experimental data and biological pathway analyses. Further expression level validation of all these target biomarkers and functional validation of selected gene/protein biomarkers were carried out, and a final gene/protein biomarker (UQCRB) was identified.