ABSTRACT
We studied the effect of an NO donor, nitrosyl iron complex with N-ethylthiourea, on Nrf2-dependent antioxidant system activation of tumor cells in vitro. The complex increased intracellular accumulation of Nrf2 transcription factor and induced its nuclear translocation. It was shown that both heme oxygenase-1 gene and protein expression increased significantly under the influence of the complex. Nrf2 activation was accompanied by a decrease in the intracellular accumulation of proinflammatory transcription factor NF-κB p65 subunit and expression of its target genes. The cytotoxic effect of N-ethylthiourea leads to induction of Nrf2/HO-1 antioxidant response and suppression of NF-κB-dependent processes in tumor cells.
Subject(s)
Heme Oxygenase-1 , Iron , NF-E2-Related Factor 2 , Thiourea , Humans , NF-E2-Related Factor 2/metabolism , NF-E2-Related Factor 2/genetics , Thiourea/analogs & derivatives , Thiourea/pharmacology , HeLa Cells , Heme Oxygenase-1/metabolism , Heme Oxygenase-1/genetics , Iron/metabolism , Transcription Factor RelA/metabolism , Transcription Factor RelA/genetics , Nitrogen Oxides/metabolism , Nitrogen Oxides/pharmacology , Antioxidants/pharmacologyABSTRACT
The effect of a new pyridoxine derivative B6NO on doxorubicin cytotoxicity and Nrf2-dependent cellular processes in vitro was studied. Antioxidant B6NO enhances the cytotoxic effect of doxorubicin on tumor cells, which is associated with G2/M cell division arrest and an increase in activity of proapoptotic enzyme caspase-3. The antioxidant promotes intracellular accumulation and nuclear translocation of Nrf2 transcription factor in non-tumor and tumor cells. In non-tumor cells, B6NO increases the expression of antioxidant system proteins and reduces ROS generation in the presence of doxorubicin. In tumor cells, no activation of Nrf2-dependent processes occurs under the action of the antioxidant. Our findings demonstrate the prospect of further studies of pyridoxine derivatives as antioxidants to reduce adverse reactions during chemotherapy.