Effects of Dichloroacetonitrile on HepG2 Cells Cycle

Objective To explore the role of p53 and chk1 in the cell cycle arrest induced by dichloroacetonitrile (DCAN) in human hepatocellular carcinoma cell line HepG2 cells.

Methods HepG2 cells were exposed to 50 and 400 μmol/L DCAN in Dimethyl sulfoxide (DMSO) for 24 h, and HepG2 cells treated with DMSO only were served as the control. The distribution of cells in different phases of cell cycle was tagged by propidium iodide (PI) staining and determined by flow cytometry kits; the expressions of p53 and chk1 mRNA was quantified by reverse transcription real-time polymerase chain reaction assay.

Results Compared with the control group, the proportion of G₁-phase cells in the 400 μmol/L DCAN-treated group was decreased, while the proportion of G₂-phase cells was increased (P < 0.05). The expression of p53 mRNA was down-regulated in the 400 μmol/L DCAN-treated group (P < 0.05), but no significant effect was observed on the expression of chk1 mRNA.

Conclusion High concentration of DCAN may arrest HepG2 cells at G₂ phase, inhibit the expression of p53 mRNA, but not affect the expression of chk1 mRNA.