Age and gender affect DNMT3a and DNMT3b expression in human liver

Area of Science:

• Epigenetics
• Molecular Biology
• Cancer Research

Background:

• DNA methylation, crucial for gene regulation, is mediated by DNA methyltransferases (DNMTs).
• Elevated DNMT levels are observed in various cancers, and a specific DNMT3b polymorphism is linked to increased cancer risk.
• Factors influencing DNMT expression in human tissues remain largely undetermined.

Purpose of the Study:

• To investigate the impact of ageing, cigarette smoking, and gender on DNA methyltransferases 3a (DNMT3a) and 3b (DNMT3b) expression levels in human liver tissue.
• To explore potential correlations between these demographic and lifestyle factors and DNA methylation status.

Main Methods:

• Analysis of DNMT3a and DNMT3b expression in human liver tissue samples from different age groups, genders, and smoking statuses.
• Statistical comparison of expression levels across these groups.
• Genotyping for the DNMT3b (C-->T) variant.

Main Results:

• Both DNMT3a and DNMT3b expression were significantly higher in older individuals (56-78 years) compared to younger individuals (16-48 years).
• DNMT3b levels were significantly higher in females than in males, while DNMT3a levels showed no significant gender-based difference.
• Expression levels of both DNMTs were similar between smokers and nonsmokers.
• The DNMT3b (C-->T) variant showed a frequency distribution of CC (41%), CT (50%), and TT (9%).

Conclusions:

• Ageing and gender are significant factors influencing DNA methylation status, specifically affecting DNMT3a and DNMT3b expression in human liver tissue.
• Cigarette smoking did not appear to influence DNMT3a or DNMT3b levels in this study population.
• Further research is warranted to elucidate the clinical implications of these findings in relation to cancer risk and progression.