Knockout of human arylamine N‐acetyltransferase 1 (NAT1) in MDA‐MB‐231 breast cancer cells leads to increased reserve capacity, maximum mitochondrial capacity, and glycolytic reserve capacity

Abstract

Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can also hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. Expression of NAT1 varies between individuals and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. To date, however, the exact mechanism by which NAT1 expression affects mitochondrial bioenergetics in breast cancer cells has not been described. To further evaluate the role of NAT1 in energy metabolism MDA-MB-231 breast cancer cells with parental, increased, and knockout levels of NAT1 activity were compared for bioenergetics profile. Basal oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were measured followed by programmed sequential injection of Oligomycin (ATP synthase inhibitor), FCCP (ETC uncoupler), Antimycin A (Complex III inhibitor), and Rotenone (Complex I inhibitor) to evaluate mitochondrial bioenergetics. Compared to the cell lines with parental NAT1 activity, NAT1 knockout MDA-MB-231 cell lines exhibited significant differences in bioenergetics profile, while those with increased NAT1 did not. Significant increases in reserve capacity, maximum mitochondrial capacity, and glycolytic reserve capacity were observed in NAT1 knockout MDA-MB-231 cell lines compared to those with parental and increased NAT1 activity. These data indicate that NAT1 knockout in MDA-MB-231 breast cancer cells may enhance adaptation to stress by increasing plasticity in response to energy demand.

A readout of metabolic efficiency in arylamine N‐acetyltransferase‐deficient mice reveals minor energy metabolism changes

“…We also show that absence of the two Nat genes leads to an increase in the concentration of hepatic CoA in mice on a HFHS diet. Since CoA is overwhelmingly concentrated in the mitochondria, our study reinforces previous observations concerning mitochondrial anomalies in Nat1 KO cancer cells or in Nat1 KO mice and opens the way to studies on possible mitochondrial dysfunctions in cases of NAT enzyme deficiency (as in human NAT1/2 slow acetylators). However, the aforementioned in vivo studies demonstrated that reduced mitochondrial activity was associated with a systemic insulin resistance in Nat1 KO mice.…”

“…Recent work has addressed the role of human NAT1 in energy metabolism in cancer cells . These findings provide evidence that Nat1 KO cell lines exhibit significant differences in bioenergetic profiles and mitochondrial capacity.…”

Circular RNA hsa_circRNA_002178 silencing retards breast cancer progression via microRNA‐328‐3p‐mediated inhibition of COL1A1

“…15 The cells were cultured in high-glucose DMEM containing 10% FBS and 5% glutamine. 15 The cells were cultured in high-glucose DMEM containing 10% FBS and 5% glutamine.…”

“…The OCR and ECAR were determined by Seahorse XF24 analyzer (Agilent Technologies) as previously described. 15 The cells were cultured in high-glucose DMEM containing 10% FBS and 5% glutamine.…”

Effect arylamine N-acetyltransferase 1 on morphology, adhesion, migration, and invasion of MDA-MB-231 cells: role of matrix metalloproteinases and integrin αV

“…Inhibition of NAT1 activity in cancer cells either by siRNA-mediated silencing, small molecular inhibitors or gene deletion with CRISPR/Cas 9 editing results in changes in cell survival and invasion [5][6][7][8][9]. Deletion of NAT1 has been associated with epithelial-mesenchymal plasticity [7], a hallmark of invasive potential [10].…”