VNTR2-1 Junk dna drives the activity of telomerase gene

[corybroo]

So called “junk DNA” may affect aging and cancer.

Potential role of 'junk DNA' sequence in aging, cancer

A research team … recently identified a DNA region known as VNTR2-1 that appears to drive the activity of the telomerase gene, which has been shown to prevent aging in certain types of cells. 

Knowing how the telomerase gene is regulated and activated and why it is only active in certain types of cells could someday be the key to understanding how humans age, as well as how to stop the spread of cancer.

"Almost 50% of our genome consists of repetitive DNA that does not code for protein," Zhu said. "These DNA sequences tend to be considered as 'junk DNA' or dark matters in our genome, and they are difficult to study. Our study describes that one of those units actually has a function in that it enhances the activity of the telomerase gene."

"Our findings are telling us that this VNTR2-1 sequence contributes to the genetic diversity of how we age and how we get cancer," Zhu said. 

Subsequently, they conducted a study that looked at the length of the sequence in DNA samples taken from Caucasian and African American centenarians and control participants in the Georgia Centenarian Study, a study that followed a group of people aged 100 or above between 1988 and 2008. The researchers found that the length of the sequence ranged from as short as 53 repeats -- or copies -- of the DNA to as long as 160 repeats.

"It varies a lot, and our study actually shows that the telomerase gene is more active in people with a longer sequence," Zhu said.

there were relatively few centenarians with a short VNTR2-1 sequence as compared to control participants. However, Zhu said it was worth noting that having a shorter sequence does not necessarily mean your lifespan will be shorter, because it means the telomerase gene is less active and your telomere length may be shorter, which could make you less likely to develop cancer.

experiments that found that deleting the DNA sequence from cancer cells -- both in a human cell line and in mice -- caused telomeres to shorten, cells to age, and tumors to stop growing.