Four-Stranded DNA Found In Human Cells, Could Help Fight Cancer
By Roxanne Palmer | January 23, 2013 5:52 AM EST
You might be more familiar with DNA as a two-stranded double helix. But it turns out that it comes in a four-stranded flavor that could also be a key to fighting cancer.
Scientists from Cambridge University reported in the journal Nature Chemistry on Sunday that they had found the four-stranded structure, also known as a G-quadruplex, in living human cells. More specifically, they found them in human cancer cells. If it turns out that this G-quadruplex is involved in cancer development and growth, then it would be a prime target for new drugs.
G-quadruplexes tend to form in areas of DNA with a lot of guanine, one of the building blocks of DNA that’s abbreviated ‘G’ when writing out a DNA or RNA sequence. Usually, guanine binds to the nucleobase cytosine, but sometimes there are instances where four guanine bases can associate into a tetrad, or four-stranded structure.
Such structures have been seen in the test tube – in vitro – but never before in the natural life of a human cell, until now.
To find G-quadruplexes inside living human cancer cells, the team created antibodies that would bind to places on the genome where four-stranded structures were plentiful. Attached to the antibodies were fluorescent proteins, so the scientists could see when and where the structures emerged.
The research team from Cambridge found evidence that G-quadruplexes tend to congregate more at a point in cell division called the ‘S-phase,’ which is when DNA replicates itself. The genes that fuel cancer growth are typically ones that kick DNA replication into high gear.
“We have found that by trapping the quadruplex DNA with synthetic molecules we can sequester and stabilise them, providing important insights into how we might grind cell division to a halt,” senior author Shankar Balasubramanian told the university’s news service.
There are still many mysteries to be solved in the case of the 4-stranded DNA. They could have been selected for in evolution, or they could just be frustrating accidents – like the tangles that form on strings of Christmas lights when you’re trying to pack them all away for the year.
“It’s a philosophical question as to whether they are there by design or not – but they exist and nature has to deal with them. Maybe by targeting them we are contributing to the disruption they cause,” Balasubramanian said.
The G-quadruplex could form the basis of a targeted cancer treatment that could stop tumor growth in its tracks.
“I'm hoping now that the pharmaceutical companies will bring this on to their radar and we can perhaps take a more serious look at whether quadruplexes are indeed therapeutically viable targets,” Balasubramanian told the BBC.
SOURCE: Biffi et al. “Quantitative visualization of DNA-G quadruplex structures in human cells.” Nature Chemistry published online 20 January 2013.
To contact the editor, e-mail:
Most Popular Slideshows
- Taylor Swift Named Forbes' Second Highest Paid Country Musician [PHOTOS]
- Forever Lost: Indescribable Anguish for Malaysia Airlines MH17 Families, Remains of Some Victims May Never Be Found (PHOTOS)
- Global Aviation Accidents: UN to Form Safety Task Force, Gov'ts Should Share Intelligence Info to Avert Future Incidents on Flying Over Warzones (PHOTOS)
- Lunch with the Gods: Pope Francis Eats with Vatican Workers in Cafeteria
Join the Conversation
- NASA Astronomers Unearths Mysterious Signal That 'Could Not Be Explained By Known Physics' [Watch Video]
- Richard Norris' Successful Face Transplant Lands Him in GQ Cover [WATCH VIDEOS]
- Luxury Cruise: A 'Once In A Lifetime' Trip To Experience Environment Devastation in the Arctic
- New Technology to Build Invisible Material Using Light: Study Says
- Breaking Discovery: Industrial Pollution Reached South Pole by 19th Century
- Transfer News: FC Barcelona, Man Utd to Compete for Juan Cuadrado's Signature as Fiorentina Reveal Willingness to Sell
- Hilary Duff's New Music Video Chasing the Sun Goes Viral on YouTube [WATCH VIDEO]
- LeBron James to Return to Miami, Face Heat on Christmas Day 2014
- Shanghai Stock Exchange Will Not Extend Trading Hours
- Qatar's Surging Real Estate Prices Won't Affect Thriving Economy – Report