Notices
Results 1 to 10 of 10

Thread: advanced gene therapy and ADN usage

  1. #1 advanced gene therapy and ADN usage 
    Forum Freshman
    Join Date
    Mar 2007
    Posts
    14
    Hello

    Here is something I'm very curious about :

    From what I understand, and correct me if I'm wrong , gene therapy allows the introduction of a corrected gene into the DNA contained in a few cells, which then, will replicate in order to propagate the corrected gene, right?

    So, my questions are :

    1. what would happen if, at the age of 50, you introduce in your cells the DNA of your 30s?

    2. how would you do if you wanted to safely conserve the DNA of your young days during decades? Would a simple hair be enough?

    3. since ageing is probably due to deprecating DNA after a certain number of copies, and since we're bound to witness great advances in biology during the next decades, wouldn't be wise to conserve your young DNA for a possible use in the future?

    Feel free to share your thoughts about it


    Reply With Quote  
     

  2.  
     

  3. #2  
    Guest
    Welcome to the forum,

    Have a look at this,

    http://www.ornl.gov/sci/techresource...y.shtml#whatis

    Not my field but my guess would be that only cells which can re-grow (ie liver) would be possibilities, or where a defective gene is replaced at some point during the reproductive process. I am not aware that a complete DNA profile can be obtained from hair samples, hang around though as we do have members who can and no doubt will, repond to your questions.

    Sounds like you're going a bit wrinkly (welcome to the club) and wonder if those hairs trapped deep down in the basin might be your saviour...


    Reply With Quote  
     

  4. #3  
    Forum Freshman
    Join Date
    Mar 2007
    Posts
    14
    Thanks

    Ok, I'll wait impatiently for other replies.

    You know, in 20 years, if the technology is there, I won't want to tell myself : "arghhh ... If only I was smart enough to do a DNA backup!!!"
    Reply With Quote  
     

  5. #4  
    Forum Freshman
    Join Date
    Feb 2007
    Location
    The Netherlands
    Posts
    21
    well, i'm still no expert on this subject, but i think i can at least attempt to answer your questions....

    1: your DNA doesn't change over the years(not in the way my guess is you're thinking it changes), it's not what makes you grow older. as far as i know it's a part of your DNA called "telomeres" which are used in DNA replication that are the primary reason your DNA grows older.

    As there's only a limited amount of it, with every cell replication, you use a bit of your telomeres, and thus, your DNA grows a bit older.

    so even if you'd replace your 50-year old DNA with DNA from your 30s, it would only correct a few changes that might have gotten in your DNA over the years through radiation, replication mistakes or maybe retroviruses...it wouldn't change your age.

    2: no idea rly, my guess is the more the better, so if you get a haircut, save it all :P


    3: well, those telomeres i was talking about earlier are actually sort of a DNA as well, just very long repeating sequences which don't code for anything. through the process of DNA replication, you actually lose a bit of that DNA every time your cell replicates

    my guess is, around your 70/80's, your telomeres start running out, and you start losing DNA which actually codes for proteins, which makes you lose important proteins in your body... the loss of those proteins can cause your organ to shut down, or stop them from functioning properly, which is when you really get "old"
    grtz.
    -FaTaL_eRRoR
    Reply With Quote  
     

  6. #5  
    Forum Ph.D.
    Join Date
    Aug 2006
    Posts
    792
    N0 telomeres are added as part of the DNA replication at the 5' end, they never "tun out" as the are added newly for each replication, if what you said did happen there would be a gradual loss of DNA from generation to generation (which is exactly what telomeres set out to prevent.
    Reply With Quote  
     

  7. #6  
    Forum Freshman
    Join Date
    Feb 2007
    Location
    The Netherlands
    Posts
    21
    Quote Originally Posted by Robbie
    N0 telomeres are added as part of the DNA replication at the 5' end, they never "tun out" as the are added newly for each replication, if what you said did happen there would be a gradual loss of DNA from generation to generation (which is exactly what telomeres set out to prevent.
    hmm, are you sure?

    i'll look it up again some time, but i'm pretty sure my teacher explained it the way i just tried....:/
    grtz.
    -FaTaL_eRRoR
    Reply With Quote  
     

  8. #7 Re: advanced gene therapy and ADN usage 
    Forum Freshman
    Join Date
    Nov 2006
    Posts
    65
    Quote Originally Posted by sleidia
    Hello :)

    Here is something I'm very curious about :

    From what I understand, and correct me if I'm wrong , gene therapy allows the introduction of a corrected gene into the DNA contained in a few cells, which then, will replicate in order to propagate the corrected gene, right?

    So, my questions are :

    1. what would happen if, at the age of 50, you introduce in your cells the DNA of your 30s?

    2. how would you do if you wanted to safely conserve the DNA of your young days during decades? Would a simple hair be enough?

    3. since ageing is probably due to deprecating DNA after a certain number of copies, and since we're bound to witness great advances in biology during the next decades, wouldn't be wise to conserve your young DNA for a possible use in the future?

    Feel free to share your thoughts about it :)
    Hi Sleidia,

    I have a 12 year old degree in genetics, so this comes from a very dangerous source (somebody who used to know what he was talking about but who aren't too sure anymore!).

    Firstly, gene therapy doesn't normally place correct DNA in just a few cells and then let the body do the rest of the work. Since the biggest part of the body doesn't replicate itself from just a few cells, that method wouldn't work and you would still be left with a predominantly wrong genome. The only place I can think of where only a few cells replaced might have an effect on the whole body is the bone marrow (where blood cells are made) and possibly in the endocrine system (hormones and glands etc). I don't think the liver would work either as Megabrain suggested, because I can't see why a little piece of correct inserted liver would be preferred above erroneous cells in replication and eventually correct the whole organ. My guess is that the liver would still largely remain ill.

    The way gene thrapy does work is by placing as many correct copies as possible into as big a part of the body as possible. Let's say you have an hereditary lung disease which is being treated by gene therapy. The preferred method would probably be to use a virus that naturally target the lungs (pneumonia for instance), cut the pieces out of it that causes you to become ill and insert correct copies of whatever gene you want to fix. The virus will then still go ahead as normal and use it's natural method of infecting your cells, but instead of causing you to become ill, it will be placing correct copies of the gene in all the cells of your lungs.

    Now to go to your numbered questions.
    1)As was said by other respondents, the DNA of an individual stays largely the same throughout their lives and is virtually indistinguishable in your 50's compared to your 30's. I agree with the statement that a major part af ageing is caused by gradually shortening telomeres. Telomeres are something like the piece of plastic at the end of your shoe laces. Their only function seem to be to hold everything together and to make sure that the whole chromosome doesn't start coming apart. These telomeres do seem to lose a tiny piece from their ends with every replication and eventually this starts causing problems with ageing. This is a whole field of study and there are very clever people devoting their whole lives to try and find ways of fixing telomeres for instance. I know that there was also (and probably still is) research into the existence of genes that actually code to make us older. If genes like these do exist and can be deleted from your body, this will take the part of your genes that deliberately make you older away and cause less ageing! Another reason for ageing is the by products of being alive! Your metabolism causes things like free radicals to be produced in your body. These are charged molecules which then bind somewhere else in the cell and cause damage in doing so. If they bind to your DNA (like they often do), this causes ageing. Taking lots of anti-oxidants that bind to and thereby neutralise free radicals might work, but there is also another and probably more effective "cure" for this. All you have to do is to continually starve yourself! It's been shown conclusively that mammels that never overfeed for long periods and that stay on the verge of starvation their whole lives live significantly longer than well fed individuals. This is probably because they have a lower level of metabolism and therefore less free radicals and less ageing. If I remember correctly more than 50% can be added to lab animal's lifespans in this way.

    2) I'm quite sure that a single hair follicle can't be used to get a full copy of an individual's DNA from. I stand to be corrected on this though.

    3) You can freeze something if you want, but I don't think it will help much with ageing since your genome doesn't really change with age as I said before.

    I unfortunately have to go now and can't elaborate any more, but if you have more questions or if this is not clear, please let me know and I'll try to answer them later!
    Reply With Quote  
     

  9. #8  
    Forum Freshman
    Join Date
    Mar 2007
    Posts
    37
    I heard today that ageing (probably) also has something to do with the degree of methylation of the DNA (heard this today in my Epigenetics-class). Appearently, the longer you live, the more of your DNA gets methylated, which is irreversible (appearently smoking causes a massive rise in methylation level in your genome). I also heard that you can't remove the methylgroup (usually on a C which is basepaired to a G, or recently discovered also basepaired to the A), but that you can try to inhibit the enzymes that put the methylgroup (e.g. methyltransferase) on new cells. Maybe this could be a way of staying youg(er) ?
    Reply With Quote  
     

  10. #9  
    Forum Sophomore
    Join Date
    Sep 2006
    Location
    Edmonton, AB, Canada
    Posts
    120
    I would be hesitant to try and stop the placement of methyl groups ... because it has many important functions. Such as ... methyl directed mis-match repair.

    It would be an interested experiment ... but I feel that the accumulation of mutations would have a greater and faster effect on lifespan than the accumulation of methyl groups.
    Would definitely be worth looking into though!
    It is not so much that I have confidence in scientists being right, but that I have so much in nonscientists being wrong. --- Isaac Asimov
    Reply With Quote  
     

  11. #10  
    Forum Freshman
    Join Date
    Mar 2007
    Posts
    14
    Hi guys

    Thanks for all the replies.
    Unfortunately, my current workload prevents me from doing some research.
    I'll come back later when I have more time to make a good use of your posts.

    Meanwhile, people who are interested might want to have a look at those articles :

    http://books.guardian.co.uk/reviews/...999578,00.html
    http://www.prospect-magazine.co.uk/a...ls.php?id=8152
    http://news.nationalgeographic.com/n..._lifespan.html
    http://www.sciam.com/print_version.c...8083414B7F0000

    ( a special thank to Burger! )
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •