This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.bbc.co.uk/news/science-environment-21091066

The article has changed 3 times. There is an RSS feed of changes available.

Version 0 Version 1
'Quadruple helix' DNA seen in human cells 'Quadruple helix' DNA seen in human cells
(about 5 hours later)
By Jonathan Amos Science correspondent, BBC NewsBy Jonathan Amos Science correspondent, BBC News
Cambridge University scientists say they have seen four-stranded DNA at work in human cells for the first time.Cambridge University scientists say they have seen four-stranded DNA at work in human cells for the first time.
The famous "molecule of life", which carries our genetic code, is more familiar to us as a double helix.The famous "molecule of life", which carries our genetic code, is more familiar to us as a double helix.
But researchers tell the journal Nature Chemistry that the "quadruple helix" is also present in our cells, and often in functions related to cancer. But researchers tell the journal Nature Chemistry that the "quadruple helix" is also present in our cells, and in ways that might possibly relate to cancer.
They suggest that control of the structures could provide novel ways to fight the disease.They suggest that control of the structures could provide novel ways to fight the disease.
"The existence of these structures may be loaded when the cell has a certain genotype or a certain dysfunctional state," said Prof Shankar Balasubramanian from Cambridge's department of chemistry."The existence of these structures may be loaded when the cell has a certain genotype or a certain dysfunctional state," said Prof Shankar Balasubramanian from Cambridge's department of chemistry.
"We need to prove that; but if that is the case, targeting them with synthetic molecules could be an interesting way of selectively targeting those cells that have this dysfunction," he told BBC News."We need to prove that; but if that is the case, targeting them with synthetic molecules could be an interesting way of selectively targeting those cells that have this dysfunction," he told BBC News.
Tag and trackTag and track
It will be exactly 60 years ago in February that James Watson and Francis Crick famously burst into the pub next to their Cambridge laboratory to announce the discovery of the "secret of life".It will be exactly 60 years ago in February that James Watson and Francis Crick famously burst into the pub next to their Cambridge laboratory to announce the discovery of the "secret of life".
What they had actually done was describe the way in which two long chemical chains wound up around each other to encode the information cells need to build and maintain our bodies.What they had actually done was describe the way in which two long chemical chains wound up around each other to encode the information cells need to build and maintain our bodies.
Today, the pair's modern counterparts in the university city continue to work on DNA's complexities.Today, the pair's modern counterparts in the university city continue to work on DNA's complexities.
Balasubramanian's group has been pursuing a four-stranded version of the molecule that scientists have produced in the test tube now for a number of years.Balasubramanian's group has been pursuing a four-stranded version of the molecule that scientists have produced in the test tube now for a number of years.
It is called the G-quadruplex. The "G" refers to guanine, one of the four chemical groups, or "bases", that hold DNA together and which encode our genetic information (the others being adenine, cytosine, and thymine).It is called the G-quadruplex. The "G" refers to guanine, one of the four chemical groups, or "bases", that hold DNA together and which encode our genetic information (the others being adenine, cytosine, and thymine).
The G-quadruplex seems to form in DNA where guanine exists in substantial quantities.The G-quadruplex seems to form in DNA where guanine exists in substantial quantities.
And although ciliates, relatively simply microscopic organisms, have displayed evidence for the incidence of such DNA, the new research is said to be the first to firmly pinpoint the quadruple helix in human cells. And although ciliates, relatively simple microscopic organisms, have displayed evidence for the incidence of such DNA, the new research is said to be the first to firmly pinpoint the quadruple helix in human cells.
'Funny target''Funny target'
The team, led by Giulia Biffi, a researcher in Balasubramaninan's lab, produced antibody proteins that were designed specifically to track down and bind to regions of human DNA that were rich in the quadruplex structure. The antibodies were tagged with a fluorescence marker so that the time and place of the structures' emergence in the cell cycle could be noted and imaged.The team, led by Giulia Biffi, a researcher in Balasubramaninan's lab, produced antibody proteins that were designed specifically to track down and bind to regions of human DNA that were rich in the quadruplex structure. The antibodies were tagged with a fluorescence marker so that the time and place of the structures' emergence in the cell cycle could be noted and imaged.
This revealed the four-stranded DNA arose most frequently during the so-called "s-phase" when a cell copies its DNA just prior to dividing.This revealed the four-stranded DNA arose most frequently during the so-called "s-phase" when a cell copies its DNA just prior to dividing.
Prof Balasubramaninan said that was of key interest in the study of cancers, which were usually driven by genes, or oncogenes, that had mutated to increase DNA replication.Prof Balasubramaninan said that was of key interest in the study of cancers, which were usually driven by genes, or oncogenes, that had mutated to increase DNA replication.
If the G-quadruplex could be implicated firmly in the development of some cancers, it might be possible, he said, to make synthetic molecules that contained the structure and blocked the runaway cell proliferation at the root of tumours. If the G-quadruplex could be implicated in the development of some cancers, it might be possible, he said, to make synthetic molecules that contained the structure and blocked the runaway cell proliferation at the root of tumours.
"We've come a long way in 10 years, from simple ideas to really seeing some substance in the existence and tractability of targeting these funny structures," he told the BBC."We've come a long way in 10 years, from simple ideas to really seeing some substance in the existence and tractability of targeting these funny structures," he told the BBC.
"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.""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."
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmosJonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos