Trimethylglycine betaine effects on NFκB, HIF1A and NFE2L2/AP-1 pathways, mitochondrial activity, glucose import, and levels of ROS, thiols and lipids in HeLa cells

Abstract

In vivo studies involving humans have shown that the major beet root betaine trimethylglycine has cancer-preventing and cancer-suppressing effects in various malignancies. Yet, the molecular basis underlying these effects has been poorly studied.In this study, HeLa cells were treated with two concentrations of betaine (10 and 30 mg/mL) for 24 h, with subsequent assessment of functioning of the NFE2L2/AP-1, NFκB and HIF1A pathways using 22 RNAs expression qPCR-based analysis. Along this, we measured glucose import rate, mitochondrial function, cellular ROS, thiols and lipids content using flow cytometry.At the higher concentration, betaine disrupted (but not actually suppressed) the NFκB and HIF1A pathways functioning, while had no effect on the NFE2L2/AP-1 pathway. Among the net physiological effects, a slight increase in cellular phospholipids and a moderate decrease in mitochondrial function were observed under the higher concentration treatment conditions. Glucose import rate, triglycerides and thiols content, and ROS generation were not affected.To conclude, betaine significantly deregulated NFκB and HIF1A pathways, while having only a modest influence on metabolic parameters of the cells reflecting limited outcome of signaling disruption of the NFκB and HIF1A pathways. Additionally, challenges related to betaine dosing and side-effects accounting in clinical practice are worth considering. Generally, betaine properties render it a low-priority new era anti-cancer signaling agent, despite some human volunteers data existing and the revealed and confirmed MYC down-regulation.