Harvard Stem Cell Breakthrough

[DrMachine]

The cells generated by this hybrid approach would actually be useless in direct stem cell treatments. They can't be used in transfers because they're abnormal cells that aren't identical to regular stem cells -- because they are a fusion of two cells, they have twice the number of chromosomes (92 instead of 46), and there's no current technique available for halving the chromosome number.

This is a neat technique in that it helps us better understand the nuclear reprogramming of a cell, and since they appear to be able to differentiate into various tissues, they might be useful in learning how different pathologies affect the cell. However, if you're looking to make stem cell lines identical to the patient (that might one day be transferred to replace damaged tissue), you'd still have to make them as fresh embryos using the South Korean SCNT technique.

you got all that out of that "blurb"?

EDIT - what I mean to say is...you're stretching it a bit using some pretty odd assumptions

[Xander Boune]

you got all that out of that "blurb"

No, but I know about cell hybrids, and I read other articles describing this technique. For one, there's a more balanced article about these cell lines over at bbcnews.

Edit: here -

http://news.bbc.co.uk/2/hi/health/4174400.stm

[DrMachine]

No, but I know about cell hybrids, and I read other articles describing this technique. For one, there's a more balanced article about these cell lines over at bbcnews.

Edit: here -

http://news.bbc.co.uk/2/hi/health/4174400.stm

I just think that you are making an assumption on the chromosome number, the article didn't explicitly say if they irradiated one of the cell lines or not

and your second point doesn't really hold true, as these cell lines discuss "potential" and not how it actually is

[Xander Boune]

I just think that you are making an assumption on the chromosome number, the article didn't explicitly say if they irradiated one of the cell lines or not

Granted, I haven't read the actual Science article yet, and it doesn't seem to be up on the website. But as far as cell fusions go, they're obviously starting with double the number of chromosomes, and if you're going to use them as possible replacement tissues in the future, irradiating them first is probably something you don't want to do. I think that these cells will have use as cell lines in which you can study differentiation and patholgies affecting different tissues, but since they're starting as abnormal cells, I don't believe they can be used in possible stem cell therapies.

and your second point doesn't really hold true, as these cell lines discuss "potential" and not how it actually is

I'm not sure what you're saying here. Can you clarify?

EDIT: Okay, if you mean as potential in stem cell therapies, it's true that tissue replacement using embryonic cells in humans is still a ways off, but embryonic cells that are identical to the patient would hold more promise than these abnormal hybrid cells.

[DrMachine]

Granted, I haven't read the actual Science article yet, and it doesn't seem to be up on the website. But as far as cell fusions go, they're obviously starting with double the number of chromosomes, and if you're going to use them as possible replacement tissues in the future, irradiating them first is probably something you don't want to do. I think that these cells will have use as cell lines in which you can study differentiation and patholgies affecting different tissues, but since they're starting as abnormal cells, I don't believe they can be used in possible stem cell therapies.



I'm not sure what you're saying here. Can you clarify?

EDIT: Okay, if you mean as potential in stem cell therapies, it's true that tissue replacement using embryonic cells in humans is still a ways off, but embryonic cells that are identical to the patient would hold more promise than these abnormal hybrid cells.

1. why on earth would anyone make a chimeric cell line and have an abnormal number of chromosomes? it doesn't make sense to go through all that trouble just to have cells that are unstable due to abnormal chromosome numbers...I just think it would an exercise in futility

2. I thought that was the point of the (small) article to say that this could show promise...but taking embryonic cells and fusing them to epithelial cells from a patient you could in essence generate customized and specific embryonic-level stem cells on demand and in vitro

[greg donovan]

"If future experiments indicate that this reprogrammed state is retained after removing the embryonic stem cell DNA — currently a formidable technical hurdle — the hybrid cells could theoretically be used to produce embryonic stem cells lines that are tailored to individual patients without the need to create and destroy human embryos," said a summary of the research reported on the Science site.

i think this paragraph is the one that is causing the confusion.

it appears that the new cell may now have an abnormal number of chromosomes.

if they can seperate the two cells, AND keep the new qualities they are golden. and that appears to be the problem.

[DrMachine]

i think this paragraph is the one that is causing the confusion.

it appears that the new cell may now have an abnormal number of chromosomes.

if they can seperate the two cells, AND keep the new qualities they are golden. and that appears to be the problem.

I didn't see that as the problem as much as I think it's interpretation of a media interpretation of a scientific study

we're (the nerds) reading our own knowledge and experience into it

[Captain Nate]

But...but...I thought Americans couldn't do stem cell research!

[RODGER]

Heh. I read "Howard Stern Cell Breakthrough."

hoo hoo
tell em fred

[Xander Boune]

First, let me say that I'm happy there's another biodork on the board. It's rare that I get to talk to people who both like comics and biology, so big ups to you.

1. why on earth would anyone make a chimeric cell line and have an abnormal number of chromosomes? it doesn't make sense to go through all that trouble just to have cells that are unstable due to abnormal chromosome numbers...I just think it would an exercise in futility

We should probably take this to PM because most people on the board probably could care less about the specifics, but here's my point: As I understand it, when you make these hybrid cells, you have a fusion of two cells, nuclear material and all. They suffer from tetraploidy. It's true that you can irradiate the cells to remove extra chromosomes in attempts to stablize the line, but this causes significant chomosomal rearrangements, DNA damage, and you cannot ensure that they would keep exactly one set of each of the chromosome pairs. Because of these defects, you certainly couldn't use these stable lines as possible cell tissue replacement, which is why these lines are good for basic study but not as possible theraputic lines. As such, they aren't as good as the cloned patient specific lines being made in Woo-Suk's lab.

I just called up my brother who works as a lab manager at Harvard Med, and he's read up a little on this work and he seems to agree with me. As a biological tool, they can provide insite into nuclear reprogramming, but because you can't eliminate exactly one set of chromosomes without damaging the cell and rearranging its nuclear material, they're no good for possible tissue repair.

2. I thought that was the point of the (small) article to say that this could show promise...but taking embryonic cells and fusing them to epithelial cells from a patient you could in essence generate customized and specific embryonic-level stem cells on demand and in vitro

That's definitely not what I got from the BBC article, where scientific experts there reiterated the tetraploidy aspect of these cells and their inability to be used in theraputic studies. But, my brother told me that this lab may have some preliminary experiments where they fused denucleated embronic stem cells with the epithelial somatic cells, and if they could get this type of fusion to work, then they could get around the anaploidy aspect of their current cells and may have something much more promising.