Follow Slashdot stories on Twitter


Forgot your password?

Cell Division Reversed for the First Time 238

SubtleGuest writes "Gary J. Gorbsky, Ph.D., a scientist with the Oklahoma Medical Research Foundation, has found a way to reverse the process of cell division. The discovery could have important implications for the treatment of cancer, birth defects and numerous other diseases and disorders. Gorbsky's findings appear in the April 13 issue of the journal Nature. "No one has gotten the cell cycle to go backwards before now," said Gorbsky. "This shows that certain events in the cell cycle that have long been assumed irreversible may, in fact, be reversible." In the lab, Gorbsky and his OMRF colleagues were able to control the protein responsible for the division process, interrupt and reverse the event, sending duplicate chromosomes back to the center of the original cell, an event once thought impossible. Here is a video of it happening."
This discussion has been archived. No new comments can be posted.

Cell Division Reversed for the First Time

Comments Filter:
  • by sqrt(2) ( 786011 ) on Thursday April 13, 2006 @02:54AM (#15119229) Journal
    It wouldn't. A smoker only feels "calmed down" because their craving has been satiated. The physical effects of nicotine increase stress on the brain and heart, they can focus because they're not constantly thinking about when they'll get their next hit, or how long they'll have to wait.
  • by rbowes ( 967998 ) on Thursday April 13, 2006 @02:57AM (#15119243)
    On the left you are seeing phase contrast microscopy, changes in the cell cause changes in the refraction of light. On the right hand you are seeing fluorescence microscopy, special fluorescent proteins have been added on the end of specific proteins in the cell and when certain light is applied they fluoresce.
  • by dukiebbtwin ( 912572 ) on Thursday April 13, 2006 @03:06AM (#15119266)
    From the article "Time-lapse phasecontrast and fluorescence images were collected from cells grown on glass coverslips using a Zeiss Axiovert 200M microscope equipped with a Hamamatsu ORCA camera." They use a fancy (and expensive) inverted light microscope with a digital camera attached to it to take the images. The section on the right part of the movie is made using with a fluorescence stain as the cell proceeds through mitosis. There is a light source attached to the microscope that emits light at a certain wavelength to excite the fluorescence stain that can be bound to a variety of things - mitochondria, DNA, etc. In this case the fluorescence is bound to alpha-tubulin-GFP. Alpha-tubulin is a protein found in microtubules which are involved with cell shape and cell structure. GFP merely means "Green Fluorescent Protein" - that it will fluoresce in the green wavelength. 1reseach/a_appli/12/contents.html [] Use of fluorescence in biochem is really fascinating, and fortunately I have a good amount of experience as a student using fluorescence as a tool. You can bind several fluorescence probes to a cell and get some really cool images: =g002761&company=probes []
  • by HappyEngineer ( 888000 ) on Thursday April 13, 2006 @03:22AM (#15119319) Homepage
    I can't say whether or not you have ADHD, but I'd just like to correct a misconception that ADHD just implies a lack of attention. The name is a misnomer. ADHD is really about a lack of ability to control attention. An ADHD person will sometimes hyper focus to the exclusion of everything and sometimes have no ability to feel comfortable continuing to do anything for very long. Obviously, everyone falls somewhere on that sort of scale. It's just when someone hits those extremes too often that it is a problem.
  • by dondelelcaro ( 81997 ) <> on Thursday April 13, 2006 @04:04AM (#15119423) Homepage Journal
    The ability to return a cell to metaphase upon the removal of a chemical (Flavopiridol) which causes the mitotic exit of cells which are expressing non-degredatable Cyclin B is interesting, but it definetly tells us nothing about how to reverse this process in non-transformed human cells. The press release is a bit too effusive about the potential of this finding to radically transform the treatment of cancer, etc. as the finding primarily recomfirms the hypothesis that the degredation of cyclin B is what gives directionality to the cell process, and by blocking the degredation of Cyclin B, you can reverse the cell cycle.

    And just in case you're confused like the submitter, there's way more than one protein involved in the cell division process in any eukaryotic cell; Cyclins like Cyclin B are very important, but it's a whole host of proteins that are involved in ushering the cell from G1 to S to G2 to M; assuring alignment, proper exit, arrest upon damage, etc. [One could even argue that the whole point of most cells is to divide, and so every bit of the cell is important and/or participates in some way in the process...]
  • Re:Stem Cells (Score:2, Informative)

    by lazybratsche ( 947030 ) on Thursday April 13, 2006 @04:06AM (#15119426)
    Slightly longer answer:

    No, because this isn't a complete reversal of cell division. It doesn't somehow "un-replicate" the DNA, it just reverses one step of division in a cell about to divide.
  • by shawb ( 16347 ) on Thursday April 13, 2006 @05:05AM (#15119538)
    This paper [] said in the summary that this process leads to "realignment of chromosomes at themetaphase plate." So, they do not merge back into one.

    What the scientists were mostly concerned with is the fact that this supported the theory that a particular protein directed cell division, at least during a certain phase. The partial reversal of mitosis was just an interesting side effect. The medical and other biological research interest comes in place because now that we have identified this protein and proven that it is indeed the one that regulates mitosis, we can prevent further mitosis by the use of an inhibitor chemical. While this may seem to be a possible cure for cancer, such a discovery would be extremely difficult to put into practice as a pill you take or shot you take. This inhibitor would likely suspend mitosis of ALL cells, breaking down the functioning of many biological processes. Unless a compound is found that preferentially affects cancer cells, which may be possible due to the high division rate in some forms of cancer. This would have little to no effect on cancers caused by a failure in apoptosis. Then again "Cancer" is just a blanket term for a large number of different disorders in which a group of cells grows and divides without control, causing detriment to the rest of the body. Making cancer study mroe difficult is that it often takes failures in several different control systems for a cell to become carcinogenic, as there is a fair bit of redundancy built into these sytems. A "predisposition" to a certain type of cancer often means that one of the inherited genes controlling one arm of the control system is already flawed, so less somatic mutations [] are required before carcinogenesis. Inherited failure in too many of the control pathways would probably result in termination or developmental failure at a very early stage of embryonic development.
  • Same position they're currently in, but with a little added motivation to stop procrastinating, and actually put their mind to it, rather than giving up, saying it's "too hard", blaming it on psych studies, finding any excuse other than accepting the fact that they're too complacent with their current situation.

    a) Who said anything about not trying to quit?
    b) Who was blaming psych studies? I was simply trying to make the point that it *is* an addition, and about just how "easy" it is to quit. And the point is that it's NOT easy. Do you honestly think that so many people around the world - given what we know now - would still be smoking if it was just a matter of not bothering to buy the next pack?

    What you are saying there illustrates my point perfectly. Too complacent? Looking for an excuse? That's just as absurd as what people said about clinical depression 20 years ago ..... "Oh, don't be so lazy - just get off your arse and DO something"

    just don't come running to me when you're diagnosed with a life threatening illness you brought on with your own behavior...

    I would have no intentions of doing so - I'm very well aware of the fact that I started of my own free will, and I not going to be a hypocryte and blame the tobacco companies, either.

    Oh, yeah - that reminds me.
    Some of us are still around that started when it *wasn't* obvious or clear - to *anybody* - that smoking would do anything other than affect your wind. Hell - I competed in provincial long-distance cross-country and steeple-chase competitions while smoking a pack a day, and was on my varsity basketball & volleyball teams, and was able to run the mile in just under 6 minites. (I think my best time was around 5:53 or thereabouts - it was a LONG time ago). And I've been smoking a pack a day since I was 13 (it WAS cool to smoke back then, believe it or not). If you think I haven't tried numerous times over the years to stop, you'r e dreaming.
    I'm glad the previous poster WAS able to quit - I'm sure he sees numerable improvements in his life because of it. But to say that not being able to quite is a sign of lazyness or just a lack of willpower shows a total ignorance of the subject.

    Yes, I - and every other smoker - started of our own free will. And yes, it IS hard to quit - so try supporting those who are trying and hopefully succeeding, instead of pissing on those who *haven't* been able to do it yet.
  • by bitkari ( 195639 ) on Thursday April 13, 2006 @05:53AM (#15119626) Homepage
    A smoker only feels "calmed down" because their craving has been satiated

    Actually, a smoker feels calmed down due to elevated levels of dopamine generated by the nicotine. While withdrawl symptoms can cause stress which is then relieved by more nicotine, that doesn't discount the stimulant effects of smoking.

  • by Colonel Angus ( 752172 ) on Thursday April 13, 2006 @07:59AM (#15119887)
    ADHD medication? No. Depression medication? Yes.

    Zyban, a fanfrickin'tastic smoking cessation pill, is simply remarketed Welbutrin. Welbutrin is an anti-depressant.

    It seems that they discovered many of the smokers taking Welbutrin reported a marked decrease in cigarette cravings. Now you can buy the *exact* same drug with a different colour coating and a different name to help you quit smoking.

    I have taken it. I was doing well, until a death in the family (non-cancer or smoking-related) buggered me up. Pathetic excuse, I know.

    But while I was on Zyban I would literally go hours (unheard of any other time) without even thinking about a cigarette. It's really something else.
  • Re:MOD PARENT UP! (Score:3, Informative)

    by ncc74656 ( 45571 ) * <> on Thursday April 13, 2006 @12:19PM (#15121882) Homepage Journal

    Define "nobody." It played just fine here, on an AMD64 Linux box with mplayer and Firefox's mplayer plugin.


  • by liswinz ( 968220 ) on Thursday April 13, 2006 @04:45PM (#15124625)
    Not a dumb question at all. The images you see of the stringy stuff are actually time-lapse images (ie. still images taken once every few seconds/minutes/hours depending on your application) of the flouresence given off by GFP, or Green Flourescent Protein, attached to Alpha tubulin.

    GFP is a natural protein that was originally found in the genome some sort of deep-sea fish (I forget which), but has been used by biologists for myriad purposes since then. Bascially, it's a protein, but because of the specifics of its sequence and configuration, it emits energy (flourescence) when hit with a laser at a particular wavelength. GFP was revolutionary because, while chemists can and have designed many compounds with similar properties, they are all synthetic and have to be physically attached to whatever protein you want to look at. The flourescent properties of GFP, on the other hand, are in the form of a protein, which can be added to any cell by just adding in the DNA that codes for GFP.

    In addition, GFP isn't very large, so you can actually make hybrid proteins that have your normal protein you want to look at and the GFP directly in sequence after it all on one piece of contiguous DNA. When it's made into a protein, you get a functional protein (although you have to test this to make sure) that has a little flourescent tag attached. So not only do the cells expressing your protein glow green, but you actually get to follow where that protein is moving in real time in the cell. People have actually taken the GFP sequence and mutated it to make flourescent proteins that are excited at other wavelengths to make YFP, CFP, RFP, etc (Yellow, Cyan, Red, etc). So if you wanted, you could make 2 or 3 proteins labeled with different colors and see what all of them were doing at the same time

    The stringy stuff you see is the microtubules that attach the duplicated chromosomes along the midline and pull half of the chromosomes towards what will become one daughter cell, half to the other. The authors have taken one of the proteins that makes up these microtubules, Alpha Tubulin, and attached GFP to it in sequence. They then added that DNA to their cell lines which now express both the normal Alpha Tubulin and the GFP-Alpha Tubulin. This allows them to look at the localization of their tagged Alpha Tubulin with a normal flourescent microscope (most molecular/cell bio labs have them) without killing the cells and see what happens over time.

Evolution is a million line computer program falling into place by accident.