Effect of ErbB2 RNAi on the content of reactive oxygen species and the DNA damage in glioma U251 cell

Objective: This study was conduced to investigate the effect of ErbB2 RNAi on the content of reactive oxygen species (ROS), the DNA damage in glioma cells(U251 cells) and the cell cycle distribution. Methods: After the U251 cells were transfected with ErbB2 RNAi plasmid (pSilencer 2.1 -ErbB2), the levels of ROS and malonaldehyde (MDA) in cells were detected at different time point. The DNA damage in transfected U251 cells was also detected using single cell gel electrophoresis (SCGE) assay at different time points. The cell cycle distribution of transfected U251 cells was examined using PI staining. Results: The level of ROS remained unchanged in U251 cells up to 48h after transfection with pSilencer 2.1 -ErbB2. The content of MDA also remained unchanged up to 24h after transfection.however, 48h after transfection with pSilencer 2.1 -ErbB2, the content of MDA increased significantly, and, recoveried to the normal level 72h after transfection with pSilencer 2.1 -ErbB2.Furthermore, the DNA damage and recovered the cell cycle derangement were observed in U251 cells after transfection with pSilencer 2.1 -ErbB2. Conclusion: The inhibition of ErbB2 resulted in the change of oxidoreduction status in U251 cells, as well as the damage and reparation of DNA. (authors)