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Cambridge University Scientists Find Quadruple Helix DNA In Human Cells

samzenpus posted about a year and a half ago | from the twice-the-fun dept.

Medicine 67

SternisheFan notes that scientists at Cambridge University have found four-stranded DNA in human cells for the first time. "If you've ever studied genetics in school or college, you'll know that the structure of DNA is a double helix. You likely know that DNA carries all of our genetic code. While traditionally we think of only double helix DNA, scientists from Cambridge University in England have made an interesting discovery. According to the researchers, a quadruple helix is also present in some cells and is believed to relate to cancer in some ways. According to the researchers, controlling these quadruple helix structures could provide new ways to fight cancer. The scientists believe the quadruple helix may form when the cell has a certain genotype or operates in a certain dysfunctional state. Scientists have been able to produce quadruple helix material in test tubes for years. The material produced is called the G-quadruplex. The G refers to guanine, which is one of the base pairs that hold DNA together. The new research performed at the University is believed to be the first to firmly pinpoint quadruple helix in human cells."

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67 comments

I'm not saying it was aliens (0, Funny)

Anonymous Coward | about a year and a half ago | (#42647131)

But... it's aliens.

Re:I'm not saying it was aliens (1)

Anonymous Coward | about a year and a half ago | (#42647239)

But... it's aliens.

No it wasn't! Just because someone is a quadrahelix it doesn't make them alien, they're just differently abled.

Not differently abled... (2)

davidwr (791652) | about a year and a half ago | (#42647447)

...differently homeworlded.

Re:Not differently abled... (1)

K. S. Kyosuke (729550) | about a year and a half ago | (#42647879)

...differently homeworlded.

Homecomingly challenged?

Re:I'm not saying it was aliens (2)

Jeremiah Cornelius (137) | about a year and a half ago | (#42647455)

Occurrence corresponds to midichlorian count.

I'm pretty sure I read this book. (1)

Shag (3737) | about a year and a half ago | (#42649435)

"Taltos" by Anne Rice, wasn't it?

Re:I'm not saying it was aliens (1)

Anonymous Coward | about a year and a half ago | (#42647615)

I strongly disagree with you, its a clear sign of supreme being!
She is perfect...
Leeloo that is.
Sincerely yours,
Father Vito Cornelius

Re:I'm not saying it was aliens (0)

Anonymous Coward | about a year and a half ago | (#42648153)

It's the Engineers (Prometheus). Cancer is really they're food, we're just the host.

A DOUBLE DOUBLE HELIX! (1)

GameboyRMH (1153867) | about a year and a half ago | (#42655829)

A double double helix, all the way!! Wow, oh wow! Whoa! WHAT DOES IT MEAN!? T_T

Yea well (-1)

Anonymous Coward | about a year and a half ago | (#42647165)

Fuck them and their mutated nigger DNA.

If there was a god, niggers wouldn't exist.

Re: Yea well (0)

Anonymous Coward | about a year and a half ago | (#42649211)

And neither would you

Re:Yea well (1)

MightyMartian (840721) | about a year and a half ago | (#42651041)

If there was a god, you would be black and still feel the same way you do.

a scientists will find a fix and then get caned fo (-1, Offtopic)

Anonymous Coward | about a year and a half ago | (#42647181)

an scientists will find a fix and then get caned for testing it out.

Re:a scientists will find a fix and then get caned (4, Funny)

Jawnn (445279) | about a year and a half ago | (#42647257)

an scientists will find a fix and then get caned

for testing it out.

So, uhm... Does this scientist live in Singapore?

Re:a scientists will find a fix and then get caned (1)

FooAtWFU (699187) | about a year and a half ago | (#42650349)

He lives in Washington, DC, but he represents the state of Massachusetts. Also, he hates the Kansas-Nebraska Act.

Re:a scientists will find a fix and then get caned (1)

Jawnn (445279) | about a year and a half ago | (#42651049)

Wow. Never thought I'd get to witness the elusive "triple whoosh", but there it is.

Re:a scientists will find a fix and then get caned (1)

7-Vodka (195504) | about a year and a half ago | (#42650453)

If they are British scientists, then getting 'caned' is slang for getting high on weed.

Re:a scientists will find a fix and then get caned (1)

mattack2 (1165421) | about a year and a half ago | (#42652667)

Holy almost 20 year old reference, Batman!(*)

Heck, are most readers of slashdot even old enough to remember this? Even if they were born, were they old enough to follow the news at that time?
http://en.wikipedia.org/wiki/Michael_P._Fay [wikipedia.org]

(*) I realize THAT is a close to 50 year old reference!

Anti-semitism (-1)

Anonymous Coward | about a year and a half ago | (#42647251)

If you follow this article to it's logical conclusion, using the best standards of journalism that exist in the United States today, you can only conclude that the writter is anti-semitic. You see the double helix structure was discovered by a Jew, Credit for the discovery was taken by a goyim. Nothing wrong with this from a journalistic stand point. This is what goyim do according to the mass media. However, if this article is true, it means that a jew was wrong. Not only a jew, but a female jew. Jews / blacks and females are never wrong. I can only conclude that the writter of this article is a cracker, and should be killed.

-

Re:Anti-semitism (2)

postbigbang (761081) | about a year and a half ago | (#42648157)

Can you code? We need logic like yours in the new NRA IT initiative! Your knowledge of history, combined with your keen insight will have new recruits lining up to sign on!

Re:Anti-semitism (-1)

Anonymous Coward | about a year and a half ago | (#42648651)

Thanks. I am just doing my part to live in today's oversensationalized mass hysteria, rush to snap judgement world we live in. I understand that a deep understanding of issues / history / truth is just for faggots. There are good new stories and bad news stories. If a story does not have some aspect of hatred toward the rich male white crackers who are systematically trying to exterminate every member of the non white race, by eating black babies, it is completely unresponsible and immature to report the story.

I am perfectly happy to live in a world where scientist and engineers and industrialists are always reported as dumpy assholes trying to rip apart holes in the space time continuum or cause global warming, I truely understand and accept that the world can be saved through the magical powers of hippity-hop.

Re:Anti-semitism (0)

Anonymous Coward | about a year and a half ago | (#42650875)

Oh, cool! Let's respond to some satire about overgeneralization and stereotypes with more overgeneralization and stereotypes! The sadder part is that you probably take your mindset seriously, while the parent doesn't.

Re:Anti-semitism (1)

postbigbang (761081) | about a year and a half ago | (#42652031)

I say: if you're going to extend a meme, give it a decent shot.

Re:Anti-semitism (1)

Palamos (1379347) | about a year and a half ago | (#42650351)

I was going to comment on your work but I just can't be arsed.

They've discovered... (1)

canadiannomad (1745008) | about a year and a half ago | (#42647285)

The Fifth Element!!!

Re:They've discovered... (1)

Anonymous Coward | about a year and a half ago | (#42647423)

Nah, hers was more of an octo-helix, but they are getting closer.

Re:They've discovered... (1)

oodaloop (1229816) | about a year and a half ago | (#42647477)

More like MetroMan's from MegaMind. There's a model of his quadruple helix DNA in the Hall of Heroes.

Just wanted to point out... (5, Funny)

rak0ribz (672551) | about a year and a half ago | (#42647297)

...that "Guanine Quadruplex" works equally well as the name for either a band or a signature wrestling move.

Re:Just wanted to point out... (0)

Anonymous Coward | about a year and a half ago | (#42647513)

And "quadraplex" or simply "quad-plex" works great for a shopping center!

Re: Just wanted to point out... (1)

Urza9814 (883915) | about a year and a half ago | (#42648193)

Quick, someone register GuanineQuadruplex.tumblr.com!

xkcd.com/1025/

Re:Just wanted to point out... (0)

Anonymous Coward | about a year and a half ago | (#42650693)

your typical band would be guano quadruplex

Can anyone explain what it means and what they do? (1)

elucido (870205) | about a year and a half ago | (#42647391)

All of this biologist type speak doesn't help regular people to understand how it can help cure cancer. It does seem like it could be targeted but what the hell is it and where does it come from? is it important? Or does it only cause cancer?

Re:Can anyone explain what it means and what they (1)

Anonymous Coward | about a year and a half ago | (#42647491)

It occurs most often in rapidly dividing cells; which whilst not limited to includes cancer cells.

That's as far as the link goes as far as I can read.

Re:Can anyone explain what it means and what they (0)

Anonymous Coward | about a year and a half ago | (#42647543)

Right now, it appears to only be in the "suspicious correlation" stage. The next stage is the "procure more funding," followed by the "multiple inconclusive results" and "procure even more funding" cycle. After 3 to 5^^7 iterations of the cycle, there will be a final report that might answer your questions.

The summary mentions cancer because that's what gets the funding. To a less cynical degree, cancer is when cells behave dangerously out of normal functionality, and quad-helix DNA seems to be out of normal functionality, so they might be linked.

Re:Can anyone explain what it means and what they (1)

RaceProUK (1137575) | about a year and a half ago | (#42655765)

cancer is when cells behave dangerously out of normal functionality

And fail to trigger apoptosis in time.

Re:Can anyone explain what it means and what they (4, Informative)

ZombieBraintrust (1685608) | about a year and a half ago | (#42647563)

Wikipedia seems to indicate that these structures can form because of telomeres. Telomeres are sections of DNA on the end that repeat the same code d(GGTTAG). They prevent damage to DNA sections that hold genes. So they are important for preventing cancer. Basically the telemeres at each end can bond with each other to form these quadruplex.

Re:Can anyone explain what it means and what they (5, Informative)

interkin3tic (1469267) | about a year and a half ago | (#42647873)

They found it in dividing cells. Cancer cells divide, which is the problem, as that causes tumors. I'm assuming they used multiple cell lines, some cancerous and some not, and found it present more in cancer cells than in normal cells.

It says they're also found in S phase cells, when the DNA is being replicated. This might contribute to cancer through genomic instability. There is a LOT of DNA to copy each cell cycle. The DNA polymerase is an impressive bit of evolved machinery, if each DNA base pair were the size of a railroad tie, the polymerase would be zipping along at a thousand miles an hour, copying the railroad tracks nearly perfectly as it does. It's also pretty good at catching its own mistakes. However, changes in the structure of DNA can cause a much higher frequency of errors in copying, and consequently, can increase the rates of mutation. It might skip copying a gene important for preventing the cell from dividing.

Perhaps most importantly though, these structures being present more in cancer cells than in normal cells means they might be good targets for identifying cells that are cancerous. Perhaps we can find a drug that directly or indirectly destroys those structures when they are present in such a way that the cell itself will be killed. That would be far more targeted than current chemotherapy, which attacks all dividing cells.

Big if of course. At this point, as far as published stuff goes, it's not yet to the point where it is going to lead to something useful in hospitals in the definite future.

Real biologist here (5, Informative)

Anonymous Coward | about a year and a half ago | (#42647997)

Some portions of DNA are rich in Guanine residues. There's been a theory kicking around that these bits could form into tetromeres, which would make the two DNA strands extra sticky to each other. A number of really wierd phenotypes, including werner's syndrome which causes premature aging, can come from the inaccurate unfolding of G rich regions. Likewise the telomeres, ie the ends of the DNA which essentially work as a division counter are G-rich. As such, if the accurate unfolding, stability or stickyness of the DNA in these regions is affected, the cellular behavior will change.

The article went through using a phage library to build an antibody specific for 4 stranded DNA (NOT easy), which did not respond to 2-stranded DNA or RNA structures. They then looked at whether, when and where tetromeres could be seen in a bone cancer cell line. Oddly enough, the regions most likely to show these structures, the telomeres, didn't show tetromeres. These structures were seen when the cell was about to get ready to divide, which makes some sense, since the cell will have more DNA. (There's a fair bit of research currently going on to study DNA supercoiling- DNA is compacted down very tightly, yet almost all of it is accessible at any given time)

As far as curing cancer, any time you can isolate behavior of cancer-only cells, you have the ability to create a drug to target that function. If these tetromeres are seen only in cancerous cells, then you can design drugs against them. Beyond that, the folding and unfolding of DNA is a pretty hot topic, since volumetric compression, read speeds and accuracy are astonishing compared to even the best hard drives on the market

Fifth element's prediction? (0)

Anonymous Coward | about a year and a half ago | (#42647407)

It reminds me of The Fifth Element... Leeloo's alien DNA was very much complex...

Thus inaugurating, among geneticists (5, Funny)

Anonymous Coward | about a year and a half ago | (#42647431)

The first annual Obfuscated DNA Contest

Re:Thus inaugurating, among geneticists (3, Funny)

SJHillman (1966756) | about a year and a half ago | (#42647471)

DNA, much like the rest of the universe is already obfuscated as a result of being hacked together in Perl.

http://xkcd.com/224/ [xkcd.com]

More... (1)

Impy the Impiuos Imp (442658) | about a year and a half ago | (#42647453)

"Scientists studying the quad-helix have already determined it is heavily implicated in the alcoholism gene."

Re:More... (2)

La Gris (531858) | about a year and a half ago | (#42647609)

Do you mean a corkscrew shaped DNA?

Re:More... (0)

Anonymous Coward | about a year and a half ago | (#42647717)

Do you mean a corkscrew shaped DNA?

A corkscrew would be a single helix.
Regular double-helix DNA is two corkscrews intertwined with a 'web' between them, holding them together.
This would be a little more like braided rope (I think).

Re:More... (0)

Anonymous Coward | about a year and a half ago | (#42650001)

whoosh

Re:More... (1)

Palamos (1379347) | about a year and a half ago | (#42650369)

Wow four corkscrews, no wonder it's implicated!

Re:More... (1)

Gilmoure (18428) | about a year and a half ago | (#42647739)

*golf clap*

Re:More... (1)

PPH (736903) | about a year and a half ago | (#42649305)

Then its still a normal helix. You are just seeing double

Quad Is So Seventies (0)

Anonymous Coward | about a year and a half ago | (#42647473)

The action now is in 5.1 and 7.1 helix.
    Not to mention TH(eli)X...

Not just quadruple... (2)

Wdi (142463) | about a year and a half ago | (#42647675)

triple DNA helixes are also known, just to expand your horizon beyond what is simplified in highschool textbooks:

http://en.wikipedia.org/wiki/Triple-stranded_DNA

Re:Not just quadruple... (0)

Anonymous Coward | about a year and a half ago | (#42700395)

Calm down people, this is just what the aliens did to make us superior to all the other primates. We ARE the experiment.

Wow, exactly 60 years... (0)

Anonymous Coward | about a year and a half ago | (#42647681)

It's been exactly 60 years since DNA was discovered? wow

Conceived in a TARDIS? (0)

Anonymous Coward | about a year and a half ago | (#42647701)

Maybe the person was conceived in a TARDIS and has timelord dna. Clearly we should shoot them and see if they regenerate.

The New Agers were right!? (2)

lawpoop (604919) | about a year and a half ago | (#42647723)

Wait wait wait wait--- you're telling me those New Age kooks who said we were going to add another strand in our DNA after 2012 were actually right!?!?!

tro7lkorE (-1)

Anonymous Coward | about a year and a half ago | (#42647899)

Minutes. If9 that.

Didn't get much out of article... (1)

Mysticalfruit (533341) | about a year and a half ago | (#42647947)

What I got out of the article is that scientists found these structures and were able to image them but don't clearly understand what they do. It sounds like we'll have to mint a raft of Ph.Ds studying this until we understand what it does.

I'd not saying its cool, it really is. But it'll probably be 5 years of study before we understand what/why/how these structures work and relate to cell (mis)function.

Science onward!!!

Re:Didn't get much out of article... (4, Informative)

Biotech_is_Godzilla (2634385) | about a year and a half ago | (#42650101)

Actually, the BBC article is very misleading when it comes to pretending that this is an amazing new discovery that this lab has intrepidly worked out from first principles. The head of the lab which produced this paper is a chemist who is big in the field (in that he makes a bunch of drugs that bind G4 DNA, and farms them out to biologists who test them in their cell lines which are defective in DNA repair) but G4 DNA is something that there's a lot of circumstantial biological evidence for.

You can look at the sequence of DNA (known from the human genome project) and see where G4 structures are likely to form. You can make G4 quadruplexes from short DNA sequences in vitro and do biophysics on them to show how incredibly strongly they interact (hard to boil them apart, and you can measure this happening with a calorimeter). There's also a lot of evidence that G4 quadruplexes are a) necessary as a regulatory/structural feature of chromosomes and b) potentially very dangerous/ deleterious if you take away the proteins which allow cells to replicate across G4-forming sequences properly.

The +5 comments above got a bit confused about why G4 DNA is found in great abundance in cancer cells. The reason for this is difficult to explain quickly, but basically: in a chromosome that's chilling out, and hasn't got much going on, G4-forming guanines are paired with their complementary cytosine residues to make a double helix. They therefore can't and won't form a quadruplex until you do something to them. What allows them to form quadruplexes is the act of DNA replication. In DNA replication the double helix is 'unzipped', forming two single strands of DNA, which are then used to make new strands, complementary to each of the single strands of old DNA. [wikipedia.org]

It's the unzipping into single strands that frees up G4-forming sequences, which can then form a "knot" in the unpaired single strand of DNA by binding "sideways" to each other in the same single strand of DNA (i.e. intramolecularly) [wikipedia.org] . Someone above said this 'causes the DNA polymerase to make mistakes in replication'. What's most likely to happen (there's at least 2 strands of evidence for this) is the cell's normal replication machinery cannot deal with the G4, stalls and stops. It then waits around for ages for the G4 to be resolved. This is one cancer link - when the cell can't deal with the knot in a sensible period of time (hours), eventually the replication machinery 'gives up', the replication fork collapses, and you lose and rearrange DNA sequence, causing either massive cell death, or mutations and cancer in the few cells that do survive.

The other link, though, is what the +5 comments were getting confused about above - cancer cells appear to have more of these G4 structures than normal cells. This is in no way surprising at all though - it's not about "having more DNA", or it's about having more replicating DNA. i.e. DNA that's in a single-stranded state, and that can therefore form G4 quadruplexes. Stem cells also show more G4 DNA, as they're replicating, and replicating fast, just like cancer cells.

The 'making G4 drugs' idea comes from the same place that an awful lot of cancer treatments come from - these are fast-growing cells, and are therefore more susceptible to things that disrupt DNA replication, compared to normal cells which aren't replicating (most 'traditional' chemotherapy causes DNA damage, disrupting replication, and the main reason radiotherapy is thought to work is that it also causes DNA damage). If you drastically choke up DNA replication, you get some catastrophic cell death in fast-replicating cells, and if you can make a drug which only affects DNA replication without causing DNA damage, you can get the good effects of chemo without the bad (potential) effects of secondary cancers ten or fifteen years down the line (due to the massive dose of DNA damage you swallowed to catch the cancer, causing more cancer).

Sorry, that was a bit of an essay, but I know the guy who did this work [nih.gov] (note the 5th author) and it annoys me that the BBC only pick up on the ridiculously simple stuff, and not the clever but complicated stuff that's been done elsewhere!

Re:Didn't get much out of article... (0)

Anonymous Coward | about a year and a half ago | (#42650943)

Thank you for the fuller explanation of the science. It's always frustrating to me when news articles talk about something like it's brand-new. It happens all the time in Physics articles too, where the writer is frequently ignorant of the body of work in the field, doesn't bother doing any research, and subsequently hacks all the interesting bits out of the press release to make an article that misrepresents the focus of the scientific work. The challenge for a science writer should be to explain this kind of stuff in a way that someone who doesn't understand it can skim the article and still get the main point, which is that such a structure exists and that it can cause problems with DNA replication in a way that results in cancer.

That wasn't originally obvious in the article, and the authors simply stated a result without explaining the mechanism.

Re:Didn't get much out of article... (1)

RDW (41497) | about a year and a half ago | (#42650951)

"...(there's at least 2 strands of evidence for this)..."

I see what you did there.

X Men (1)

Virtucon (127420) | about a year and a half ago | (#42647957)

Get Patrick Stewart's wheelchair oiled up...

Failzors? (-1)

Anonymous Coward | about a year and a half ago | (#42648443)

By simple fucking on baby...don't Do, and with any prospect5 are very could sink your design aaproach. As least I won't Distributions practical purposes, was what got me watershed essay,

I for one (0)

Anonymous Coward | about a year and a half ago | (#42648573)

welcome our new Prothean overlords.

Natural evolution into.... (1)

Anonymous Coward | about a year and a half ago | (#42648901)

Leloo dallas multipass.

Obligatory DNA quote (1)

XNormal (8617) | about a year and a half ago | (#42649935)

(DNA = Douglas Noel Adams)

Haggunenons have the most impatient chromosomes in the Galaxy. Whereas most species are content to evolve slowly and carefully over thousands of generations, discarding a prehensile toe here, [...] hazarding another nostril there, the Haggunenons would have done for Charles Darwin what a squadron of Arcturan Stunt Apples would have done for Sir Isaac Newton. Their genetic structure is based on the quadruple sterated octohelix....

Species 11296? (0)

Anonymous Coward | about a year and a half ago | (#42650761)

8472 [wikipedia.org]

It is not a HELIX... (0)

Anonymous Coward | about a year and a half ago | (#42650835)

...and it's correspondingly not called a "quadruple helix". Yes, I realise that some ignorant reporter wrote that and now already we see the ignorant masses jumping onto this, but please don't keep propagating this rubbish. It is referred to as a "quadruplex", suggesting the quadrangular complex that it is.

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