Human knees

Post by **Massive Quasars** » Fri Oct 07, 2005 5:25 am

They aren't built to last 75+ years.

Post by **werldhed** » Fri Oct 07, 2005 5:39 am

Not much of your body is.

--> Hayflick Limit!

Post by **werldhed** » Fri Oct 07, 2005 6:26 am

Sorry, it happened to be just what I was studying at the moment. The nerd in me leaps out occassionally before I can do anything.

Post by **Massive Quasars** » Fri Oct 07, 2005 6:56 am

werldhed wrote:Not much of your body is.

--> Hayflick Limit!

Unacceptable.

ot: You hear about the cervical cancer vaccine?

Post by **werldhed** » Fri Oct 07, 2005 12:40 pm

I have heard, but I believe that's really a vaccine against the virus that can cause cancer, which is something that should be avoidable through safe sex practices.
The vaccine itself is nice because it kills two birds with one stone, but what we really need is a vaccine that can target cancer itself. Then we'd have potential to protect against more types of cancer. :icon14:

Post by **werldhed** » Fri Oct 07, 2005 12:43 pm

btw, cancer vaccines are of specific interest to me as I happen to be working on this project:
http://www.jimmunol.org/cgi/content/full/169/10/5622

Post by **werldhed** » Fri Oct 07, 2005 12:52 pm

btw spam:
http://www.jmir.org/2005/1/e6/
http://www.sciencedirect.com/science?_o ... 09381c3a79
http://www.ncbi.nlm.nih.gov/entrez/quer ... query_hl=1
http://www.ncbi.nlm.nih.gov/entrez/quer ... query_hl=1
http://www.ncbi.nlm.nih.gov/entrez/quer ... query_hl=1
http://www.ncbi.nlm.nih.gov/entrez/quer ... query_hl=1
http://www.ncbi.nlm.nih.gov/entrez/quer ... query_hl=1

Post by **Massive Quasars** » Fri Oct 07, 2005 7:50 pm

I know this vaccine targets the virus that causes cervical cancer. I don't think conventional vaccines will work for other types of cancers. Unless you have something else in mind?

What about this WILT thing werldhed?

http://www.gen.cam.ac.uk/sens/cancer.htm
http://www.gen.cam.ac.uk/sens/AdGpubs.htm#wilt

Post by **losCHUNK** » Fri Oct 07, 2005 8:26 pm

my knees fucked up twice within 21 years 0_o

Post by **werldhed** » Sat Nov 05, 2005 5:55 am

Massive Quasars wrote:I know this vaccine targets the virus that causes cervical cancer. I don't think conventional vaccines will work for other types of cancers. Unless you have something else in mind?

What about this WILT thing werldhed?

http://www.gen.cam.ac.uk/sens/cancer.htm
http://www.gen.cam.ac.uk/sens/AdGpubs.htm#wilt

Okay. Sorry I didn't see this before.
And sorry for the long answer...

To answer the first question, conventional vaccines don't currently work against cancer for two main reasons: antigens displayed by cancer cells vary by individual, and targeting cancers requires a very pronounced and prolonged immune response. That link I posted is about heat shock proteins (HSPs), which when linked to other proteins ellicit massive T cell proliferation (more so than normal vaccine adjuvants). HSPs are found in all cells, already linked to proteins. Isolating them from tumors may give us tumor-specific vaccines. In addition, they MIGHT work prophylactically by vaccinating against general tumor antigens, but I'm not sure how well this works.

About WILT... I haven't gotten a chance to read deGrey's articles in full, but theoretically, it's a promising approach. However, there are some general problems with it. First of all, although telomerase can help immortalize a cancer cell, many cancers also come about due to loss of telomeres. So it's kind of lose-lose -- you can get cancer if you have telomerase, and you can get it if you don't.

Second, eliminating all telomerase-activating genes in the body is not feasible in any sense. Inhibition of the genes is more possible, but he mentions cancer's ability to circumvent such inhibition.
Third, knocking out telomerase activity in mice has so far not proven to be a cure-all. The cells are still susceptible to cancer. It might be different in humans, but until we get good results in mice, it's not going to happen.

Nevertheless, it is an ambitious approach, and I like those sorts of things. Unfortunately, deGrey doesn't seem to have primary articles on the subject (at least I didn't find any; I didn't look really hard). I know he's not the only one persuing it, so it should be interesting to see where the idea goes from here.

Post by **werldhed** » Sat Nov 05, 2005 6:03 am

Maybe a good idea would be to use it to treat cancers where telomerase activity is promoting immortality, but lack of telomere function does not lead to cancer.

IIRC, the p53 oncogene plays a deciding factor in these cases, so maybe it would work for tumors in which p53 is not present...
I still don't know how you'd delete all telomerase genes from the patient, though...

Post by **Massive Quasars** » Sat Nov 05, 2005 6:07 am

Thank you for taking the time to respond, it's much appreciated!

Third, knocking out telomerase activity in mice has so far not proven to be a cure-all. The cells are still susceptible to cancer. It might be different in humans, but until we get good results in mice, it's not going to happen.

That may be the case, but those cells will be relatively short lived correct? Perhaps your point is that they're not short-lived enough to make the cancer threat non-fatal.

Post by **Massive Quasars** » Sat Nov 05, 2005 6:09 am

http://www.gen.cam.ac.uk/sens/cancer.htm

The telomere reserve of neonatal stem cells suffices for about a decade, judging from the age of onset of dyskeratosis congenita, a disease associated with inadequate telomere maintenance. So, in theory, a decadal repopulation of all our stem cell populations with new ones whose telomeres had been restored ex vivo, but which had no telomerase or ALT genes of their own, should maintain the relevant tissues indefinitely while preventing any cancer from reaching a life-threatening stage.

Post by **werldhed** » Sat Nov 05, 2005 6:22 am

Massive Quasars wrote:Thank you for taking the time to respond, it's much appreciated!

Third, knocking out telomerase activity in mice has so far not proven to be a cure-all. The cells are still susceptible to cancer. It might be different in humans, but until we get good results in mice, it's not going to happen.
That may be the case, but those cells will be relatively short lived correct? Perhaps your point is that they're not short-lived enough to make the cancer threat non-fatal.

Not necessarily. In those experiments, telomerase genes were removed, but the cells could still be immortalized and they were susceptible to tumor viruses that apparently found a way around the telomere problem (maybe by coding for their own form of telomerase, I don't know). If these cells were isolated and injected into other mice, they still formed tumors, despite having the telomerase genes removed. So the cells could still somehow live forever.

Post by **werldhed** » Sat Nov 05, 2005 6:24 am

One of deGrey's articles is 27 pages long. I don't think I'll be reading the whole thing tonight.

Post by **Massive Quasars** » Sat Nov 05, 2005 6:25 am

I see, thanks again for taking the time to respond.

Post by **werldhed** » Sat Nov 05, 2005 6:28 am

Massive Quasars wrote:http://www.gen.cam.ac.uk/sens/cancer.htm
The telomere reserve of neonatal stem cells suffices for about a decade, judging from the age of onset of dyskeratosis congenita, a disease associated with inadequate telomere maintenance. So, in theory, a decadal repopulation of all our stem cell populations with new ones whose telomeres had been restored ex vivo, but which had no telomerase or ALT genes of their own, should maintain the relevant tissues indefinitely while preventing any cancer from reaching a life-threatening stage.

This part was interesting. I didn't know about the 10-year thing. I know cells can handle about 50 divisions. You'd probably have to repopulate earlier, though, before problems arise.

Post by **werldhed** » Sat Nov 05, 2005 6:36 am

Massive Quasars wrote:I see, thanks again for taking the time to respond.

No problem. I love this sort of stuff, and that's why I kind of get carried on these topics, so I apologize if I start to get too technical or anything.

I'm also supposed to be doing a review on Helicobacter pylori pathogenesis right now, so I'm happy to take any excuse to avoid it.

Post by **Massive Quasars** » Sat Nov 05, 2005 6:44 am

werldhed wrote: No problem. I love this sort of stuff, and that's why I kind of get carried on these topics, so I apologize if I start to get too technical or anything.

Don't apologize for being thorough, I heard about WILT and thought it sounded interesting as an unideal means of staving off cancer until something better comes along.

Post by **Scourge** » Sun Nov 06, 2005 2:50 pm

My knees didn't even last 40. I already need new ones.