what is the effect of promoter cpg island methylation on genes in aging?
oneillrocks4ever asked:
I need to know what promoter cpg islands and methylation are, and how promoter CpG island methylation affects genes in aging.
Caffeinated Content
I need to know what promoter cpg islands and methylation are, and how promoter CpG island methylation affects genes in aging.
Caffeinated Content
June 30th, 2009 at 1:41 pm
aging
Many genes respond to signals from the environment. The genetic area that activates this response is called the ‘promoter region’. Methylation of cpg islands in the promoter region of a gene acts like a mechanical block, preventing the reading/activation of the gene. In other words, gene methylation is a mechanism for turning on/off activity of many genes.
In cancer and aging, this process of gene promoter methylation becomes abnormal. In many cancer cells there is a ‘paradoxical’ combination of hypermethylation of some genes and global (overall) hypomethylation of the entire genome. If a tumor suppressor gene (such as BRCA1 or p53) is hypermethylated then it cannot be activated. This can contribute to the carcinogenesis (and aging) process.
On the other hand, if a gene is hypomethylated, it becomes over-activated and this can convert the gene (if it is involved in cell cycle regulation) into an oncogene – a gene that promotes cancer.
Hope this wasn’t too complex to be helpful to you.
Gene methylation is an area of intense medical research because it appears to play a significant role in many chronic conditions. It is important to recognize that diet plays a major role in this process. For example, low intakes of key vitamins involved in the methylation process (folate, B2, B6 and B12) are common and play a role in many chronic diseases, including cancer and other diseases of aging.
Best wishes and good luck.