Are adult stem cells udifferentiated?

[elguapo]

I was watching an interview with Michael J. Fox tonight, and he said that there are two types of stem cells - embryonic and adult - and that adult stem cells were not undifferentiated, but rather were "older" and had a tendency to become a certain kind of cell.

I thought the answer was that even adult stem cells were undifferentiated. I thought I read on this site an article that mentioned adult follicular stem cells being investigated for the use of treating other conditions. I figured this implies that adult stem cells can still become any type of cell.

Anybody know?

 

[bubka]

yes and no, there are some that are "undifferentiated" and thus could become any other type of cell; however, thats a loose term rather and it is more difficult to get the adult cells to want to divide for a number of reasons

one is the telomeres on the end of the DNA strands constantly shortens, until eventually you are losing actual DNA code... which is not good obviously

 

[elguapo]

Thanks. That answer agrees with what Michael J. Fox was saying about adult stem cells being "cranky". He probably meant that, yeah, they are like any other stem cell, but they have more of a tendency to do something that "pure", embryonic stem cells do not have the tendency to do, like become one type of cell vs. another. I just wasn't sure what he meant by that.

Man, complicated stuff.

 

[bubka]

thats pretty much it, thats why you get identical twins when the cells spit, then become separated, they can go on to become anything, two people

but adult is much tougher, because most likely, even if they are a stem cell, they have divided many times still, and all cells have set number of divisions, after that you get problems

 

[elguapo]

Well sh*t, if after many cell division, you get problems, could this complicate things with ICX-TRC? I mean, how does follicular cell division repeat time after time with no problem?

I guess if hair follicle cells are able to divide over and over again without any problems, and ICX is multiplying those same cells, that their product should still work. ?

 

[bubka]

Well $#iT, if after many cell division, you get problems, could this complicate things with ICX-TRC? I mean, how does follicular cell division repeat time after time with no problem?

I guess if hair follicle cells are able to divide over and over again without any problems, and ICX is multiplying those same cells, that their product should still work. ?

it depends on the cell and how many divisions...

thats why cancer is more prone to places with lots of cell division, skin, colon, or anyplace where cells are constantly being damaged and being replaced

hair cloning works because for the most part, hair can grow and replicate throughout a normal lifetime, though does still thin out naturally

 

[hedgehog_info]

This website has some good information

http://stemcells.nih.gov/


"V. What are the similarities and differences between embryonic and adult stem cells?

Human embryonic and adult stem cells each have advantages and disadvantages regarding potential use for cell-based regenerative therapies. Of course, adult and embryonic stem cells differ in the number and type of differentiated cells types they can become. Embryonic stem cells can become all cell types of the body because they are pluripotent. Adult stem cells are generally limited to differentiating into different cell types of their tissue of origin. However, some evidence suggests that adult stem cell plasticity may exist, increasing the number of cell types a given adult stem cell can become."

Figure 2. Hematopoietic and stromal stem cell differentiation. Click here for larger image.

Figure 3. Plasticity of adult stem cells.

I know this forum is not about cancer. But cancer cells are often undifferentiated cells. Maybe a correlation between adult stem cells and cancer?

 

[hedgehog_info]

with regards to ICX-TRC

Have they noted any side effects with hairs not growing the right way when planted back into the scalp? I would imagine it would be hard to get the hair to grow the right way out of the scalp?

 

[docj077]

I know this forum is not about cancer. But cancer cells are often undifferentiated cells. Maybe a correlation between adult stem cells and cancer?

The grade of cancer is determined by the type of differentiation with a specific cell lineage. One can not assume that an undifferentiated cell is the only source of mutation leading to cancer. Any cell that undergoes some sort of harmful interaction with its environment can potentially become cancerous. In that case, simple somatic cells become dedifferentiated and gain the ability to change their extracellular receptors, downregulate tumor suppressors and upregulate other oncogenes.

It's very complicated, but no, there isn't always a correlation between adult stem cells and cancer.

 

[bubka]

cancer can develop from any dividing cell, most likely cells that are already differentiated, and are always reproducing, or constantly being damaged and having to be replaced. Cancer happens a lot, most of the time the cells own error checking mechanisms finds the DNA error and the cell kills itself (apoptosis) however, when this is missed, or not kept in check by a weakened or older immune system, cancer happens

 

[docj077]

Another addition to this discussion might be to point out that everyone has cancer in their body at pretty much any given moment of any given day. However, the body's error proofing mechanisms usually prevent proliferation and metastasis.

Also, it's important to note that cancer development does not require a dividing cell in all instances. Many tumor forming viruses simply flip cells into S phase and start them on the track to division.

 

[hedgehog_info]

The grade of cancer is determined by the type of differentiation with a specific cell lineage.

Do u have any links or articles on this?


I have spent a some time learning about the hair follicle and basal cell carcinoma correlation. Very interesting...

 

[docj077]

The grade of cancer is determined by the type of differentiation with a specific cell lineage.

Do u have any links or articles on this?


I have spent a some time learning about the hair follicle and basal cell carcinoma correlation. Very interesting...

Just my pathology textbook. Cancer grading and staging is very complex and is based not only upon microscopic examination with possible immunohistochemical staining, but it's also based upon the degree of metastasis, the number of nodes effected, and the amoutnt of differentiation or dedifferentiation. Flow cytometry is also very important.

If you look at a hair follicle that's going through the male pattern baldness process under a microscope and then look at a basal cell carcinoma under a microscope you'll see that they are two completely different entities.

 

[hedgehog_info]

Cool, just asking I have never heard of this in my research and would like to learn more.

In regards to male pattern baldness which i assume stands for Male Pattern Baldness? (a little new to this forum)
I will try to explain my area of research. It does not directly have to do with male pattern baldness but, there is a large and growing body of evidence that adult stem cells send signals to kick the hair cycle into catagen. Obiviously male pattern baldness has less hairs in catagen. However, on the flip side they have done animal experients and have noted these same cells that send the signals when turned on permanately develop BCC and other types of skin cancer.

Curis is trying to turn on this pathway just enough to grow hair but not have patients develop cancer.

I little inside info. Curis was trying to develop another program for stroke but use a systemic agonist of this pathway and one of the side effects they found was hair growth with a one time application.

 

[hedgehog_info]

Here are a few websites you can look at while having some coffee or beer

Cheers,

http://www.med.umich.edu/derm/research/ ... onic.shtml
http://www.nature.com/emboj/journal/v22 ... 0681a.html

 

[michael barry]

Hedgehog,

When will Curis be in phase 1 etc.?

 

[hedgehog_info]

Hi Micheal,

Hedgehog,

When will Curis be in phase 1 etc.?

Program Status

• 1st preclinical development objective reached $1.0 M cash payment received[/*:m:d0d0c]
• 2nd preclinical development objective based upon
  lead candidate selection[/*:m:d0d0c]
• Expected Q1 2007; $1.8M cash payment
  IND filing anticipated within 12 months of lead
  selection
  
  IND will trigger cash milestone or Curis may elect to codevelop
  from IND to end of Ph II to receive higher royalty
  on net sales[/*:m:d0d0c]

info was taken from http://www.curis.com