DNA Methylation of hTERT (Human Telomerase) in Saliva is Reduced in Ageing Silviatun Nihayah, Wening Sari, Yusnita, Intan Razari, Kinasih Prayuni, Ahmad Rusdan Handoyo Utomo
Graduate School of Biomedical Sciences Universitas YARSI, Jakarta, INDONESIA
Abstract
ABSTRACT
Background: Promoter methylation of the hTERT gene in blood DNA has been proposed to be an epigenetic molecular clock because it is negatively correlated with ageing. Saliva is an alternative source of DNA because it contains buccal cells. Currently, the correlation of hTERT promoter methylation and ageing using saliva is not known. Objectives: First, we determined the correlation between hTERT promoter methylation and ageing in saliva as a source of non-invasive DNA samplings instead of blood. Second, we evaluated the influence of sex on the methylation of the hTERT promoter in ageing. Method: We used a cross-sectional study design and recruited 119 subjects consisting of 25 children (1-5 y.o), 42 teens (17-19 y.o), 16 adults (20-50 y.o), and 36 elderly (60 to 84 y.o). There were 28 men and 91 women. Promoter methylation of the hTERT of extracted DNA was determined using the MSRE (methyl-specific restriction enzyme) method. The relationship between age and the percentage of hTERT methylation was assessed using the Pearson test. Results: The percentage of hTERT methylation in saliva DNA was negatively correlated with age r= -0.4305 (p-value <0.05). Negative correlation was also found in men (r= -0.376) and women (r=-0.43). Conclusion: Negative correlation between hTERT and ageing has been confirmed in saliva as a non-invasive sampling method, in both men and women. More studies using case-control designs may be required to determine the correlation between hTERT methylation and chronic diseases in the elderly population.
