Induction of DNA damage signaling genes in benzidine-treated HepG2 cells

Abstract

We examined genotoxicity and DNA damage response in HepG2 cells following exposure to benzidine. Using the Comet assay, we showed that benzidine (50-200 μM) induces DNA damage in HepG2 cells. DNA damage signaling pathway-based PCR arrays were used to investigate expression changes in genes involved in cell-cycle arrest, apoptosis, and DNA repair and showed upregulation of 23 genes and downregulation of one gene in benzidine-treated cells. Induction of G2/M arrest and apoptosis was confirmed at the protein level. Real-time PCR and Western blots were used to demonstrate the expression of select DNA repair-associated genes from the PCR array. Upregulation of the p53 protein in benzidine-treated cells suggests the induction of the p53 DNA damage signaling pathway. Collectively, DNA damage response genes induced by benzidine indicate recruitment complex molecular machinery involved in DNA repair, cell-cycle arrest, and potentially, activation of the apoptosis.

Evaluation of DNA-Damaging Effects Induced by Different Tanning Agents Used in the Processing of Natural Leather—Pilot Study on HepG2 Cell Line

“…For the purpose of the present study, we selected the HepG2 cell model, which has already proven useful for studying the genotoxicity of many direct and indirect mutagens and compounds with unknown or poorly known mechanisms of action [ 12 , 13 ]. As HepG2 cells were successfully used in several previous studies which investigated toxic potential of various dyes and agents common in the textile and leather industry [ 14 , 15 , 16 , 17 , 18 , 19 ], it seems reasonable to select them for this experiment. We considered HepG2 cells a suitable test system because they retain—to a certain extent—the activity of metabolic enzymes that are important for the biotransformation of chemicals in the liver, and exhibit many of the genotypic and phenotypic characteristics of liver cells [ 20 , 21 , 22 ].…”