1. Arylamine N-acetyltransferase 1 protects against reactive oxygen species during glucose starvation: Role in the regulation of p53 stability
- Author
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Lili Wang, Rodney F. Minchin, and Neville J. Butcher
- Subjects
0301 basic medicine ,Arylamine N-Acetyltransferase ,Cultured tumor cells ,lcsh:Medicine ,Apoptosis ,Biochemistry ,Metastasis ,HeLa ,Gene Knockout Techniques ,Oxidative Damage ,Basic Cancer Research ,Medicine and Health Sciences ,Small interfering RNAs ,RNA, Small Interfering ,lcsh:Science ,Multidisciplinary ,biology ,Cell Death ,Chemistry ,Organic Compounds ,Monosaccharides ,Cell biology ,Isoenzymes ,Nucleic acids ,Oncology ,Cell Processes ,Physical Sciences ,Cell lines ,Biological cultures ,HT29 Cells ,Intracellular ,Research Article ,Programmed cell death ,Blotting, Western ,Carbohydrates ,Cell Growth ,03 medical and health sciences ,DNA-binding proteins ,Genetics ,Humans ,HeLa cells ,Non-coding RNA ,Cell Proliferation ,Cell growth ,lcsh:R ,Organic Chemistry ,Chemical Compounds ,Contact inhibition ,Biology and Life Sciences ,Proteins ,Cell Biology ,biology.organism_classification ,Cell cultures ,Acetylcysteine ,Gene regulation ,Research and analysis methods ,030104 developmental biology ,Glucose ,Cancer cell ,RNA ,lcsh:Q ,Gene expression ,CRISPR-Cas Systems ,Tumor Suppressor Protein p53 ,Reactive Oxygen Species - Abstract
Human arylamine N-acetyltransferase 1 (NAT1) has been associated with cancer cell growth and invasion, but the underlying molecular mechanisms remain unknown. NAT1 is located on the short arm of chromosome 8 (8p21), a region that is commonly deleted in colon cancer. Previously, it was reported that HT-29 colon cancer cells, which have a large deletion at 8p21-22, show marked morphological changes, increased E-cadherin expression and altered cell-cell contact inhibition following down-regulation of NAT1 with shRNA. By contrast, no effects on growth were observed in HeLa cells. In the present study, cellular changes following knockout of NAT1 with CRISPR/Cas9 in HT-29 and HeLa cells were compared in the presence and absence of glucose. Cell growth decreased in both cell-lines during glucose starvation, but it was enhanced in HT-29 cells following NAT1 deletion. This was due to an increase in ROS production that induced cell apoptosis. Both ROS production and cell death were prevented by the glutathione precursor N-acetylcysteine. NAT1 knockout also resulted in a loss of the gain-of-function p53 protein in HT-29 cells. When p53 expression was inhibited with siRNA in parental HT-29 cells, ROS production and apoptosis increased to levels seen in the NAT1 knockout cells. The loss of p53 may explain the decreased colony formation and increased contact inhibition previously reported following NAT1 down-regulation in these cells. In conclusion, NAT1 is important in maintaining intracellular ROS, especially during glucose starvation, by stabilizing gain-of-function p53 in HT-29 cells. These results suggest that NAT1 may be a novel target to decrease intracellular gain-of -function p53.
- Published
- 2017