There are some shortcomings of animal experiments applied in chemical toxicity testing, such as long period, large cost, species differences and dose differences, which limit the use of animal experiments' results in predicting human toxicity.Accordingly, we established a toxicity testing alternative screening system in line with the toxicity endpoints which required in chemical safety evaluation and risk assessment (genotoxicity, carcinogenicity, reproductive toxicity, acute toxicity and general toxicity) based on 3R principles (replacement, reduction, refinement) for animal experiments.This system covers most of the endpoints of toxicity assessment, and molecular biology technology was also applied to integrate the toxicity test, as well as some operation was optimized in order to shorten the experimental period, reduce experimental costs, improve animal welfare.Furthermore, the results from the screening system have higher clinical relevance because it is based on the toxicity mechanisms.

Objective To screen and verify hub genes TPM1 and CALD1 that can affect the diagnosis and prognosis of bladder cancer (BLCA). Methods We obtained gene chip expression data of 414 and 188 cases of bladder cancer from TCGA and GEO, respectively. By constructing a weighted gene co-expression network analysis (WGCNA) and identifying differentially-expressed genes between tumor tissues and normal tissues, the pivotal genes that were highly associated with bladder cancer were obtained, and the STRING database was used to construct a protein interaction network to screen out prognostic-related pivotal genes. We took 29 cases of bladder cancer samples from People's Hospital of Zhengzhou as external verification results. Results A total of 915 and 464 differentially-expressed genes were screened from the TCGA database and GSE13507, respectively. Two modules with the strongest correlation were obtained through WGCNA: the blue module (Pearson cor=0.60, P=1E-44) and the cyan module (Pearson cor=0.52, P=7E-19), and 156 intersection genes were obtained. Through protein interaction network analysis, 10 pivotal genes were screened out. TPM1 and CALD1 genes had the greatest correlation with the survival of bladder cancer patients, which was verified by external experimental verification group. Conclusion TPM1 and CALD1 are closely related to the prognosis of bladder cancer patients. They are also pivotal genes to promote tumor progression.