I came across this by accident, but it appears that the effect of substances that inhibit telomerase such as curcumin, and likely other inhibitors such as resveratrol, can be blocked by N-acetyl cysteine. It is possible that taking NAC with a telomerase activator could increase its effectiveness. If not directly, than by blocking the inhibitory effects from curcumin, resveratrol and substances found in a normal diet.
Mutat Res. 2010 Jun 1;688(1-2):72-7. Epub 2010 Apr 2.
N-acetyl cysteine mitigates curcumin-mediated telomerase inhibition through rescuing of Sp1 reduction in A549 cells.
Hsin IL, Sheu GT, Chen HH, Chiu LY, Wang HD, Chan HW, Hsu CP, Ko JL.
Institute of Medical and Molecular Toxicology, Chung Shan Medical University, Taichung, Taiwan, ROC.
Abstract
Curcumin is a natural compound that has been extensively observed due to its potential as an anticancer drug. Curcumin restrains cancer cell progression via telomerase activity suppression. However, the exact mechanism is still unknown. In this study, we demonstrate that the effects of curcumin on cell viability and telomerase activity can be blunted by reactive oxygen species (ROS) inhibitor N-acetyl cysteine (NAC). The ROS induced by curcumin in A549 cells was detected by flow cytometry. Using Western blot and RT-PCR, human telomerase reverse transcriptase (hTERT) decreased in the presence of curcumin. Sp1 is one of the important transcription factors in hTERT expression. Our data showed that curcumin decreases the expression of Sp1 through proteasome pathway. In addition, NAC blunted the Sp1 reduction and hTERT downregulation by curcumin. Further, reporter assay and DNA affinity precipitation assay confirmed the influence of curcumin on Sp1 in hTERT regulation. This is the first study to demonstrate that curcumin induces ROS production resulting in Sp1 binding activity inhibition and hTERT downregulation.
Copyright 2010 Elsevier B.V. All rights reserved.
PMID: 20363232