Telomeres--interesting info for my students

As everyone should know by now, chromosomes are long strands of DNA.  

In 1961--long before we learned how to decode genes--researchers trying to replicate human cells in culture found that cells would only divide between 23 and 26 times, no matter how careful they were.  This was apparently first described by Leonard Hayflick, and was soon named the Hayflick limit.  

This limit to how many times a cell can replicate is why a baby's skin is so smooth and opaque compared to your grandparent's hand: the older person has fewer cells.  The limit eventually causes failure of vital systems, leading to death.

In 1971 a Russian biologist, Aleksay Olovnikovat, published a paper speculating that when a cell divided, the ends of chromosomes couldn't be completely duplicated.  If so, this would cause chromosomes to get slightly shorter each time the cell divided.

If true, after a certain number of replications cells the telomeres would be too short (perhaps gone altogether), so in later replications the cell would start losing actual functional DNA, causing the cell to become non-viable.  This would explain the Hayflick limit.  Aha.

But if this was all correct, how were cancer cells able to reproduce indefinitely?  Stay tuned.

In 1975–1977, Elizabeth Blackburn, Joseph Gall and others discovered that the ends of every chromosome contained a simple DNA sequence (TTAGGG) repeated lots of times.  The sequence--called a telomere--was far too simple to be a functioning gene, so what did it do?  Could it be the end of the chromosome that Olovnikovat guessed couldn't be duplicated?

In 1985 Blackburn and Carol Greider found that cells of a species of protozoan managed to replicate without limit, suggesting it had a way to regenerate its telomeres.  And eventually they found how the protozoan did that trick: it produced an enzyme they named telomerase.

With the enzyme identified, other researchers found that embryos produced telomerase, which allowed fetal cells to replicate 40 to 60 times during a time of intense cell division, but that after that the production of telomerase stopped, and further cell division began to shorten the telomeres.

(In 1991 Calvin Harley and co-workers analyzed the weight of chromosomes for subjects from 6 months to 95 years old, and found a linear relationship between mass and age: each time a cell divided, the chromosomes lost between 50 and 100 base pairs .  Presumably the loss in chromosome weight was due to shortening of the telomeres.)

So to review: human cells are limited in the number of times they can replicate, now known to be due to shortening of the telomeres.  But an enzyme--identified and isolated in 1985--regenerates the telomeres, theoretically enabling a cell to replicate indefinitely.

Now: All this is well known in cell biology.  Question is, what's happened with these discoveries in the 37 years since telomerase was identified in 1985?

If someone with lots of money wanted to have the skin and physique of a 40-year-old at age 70, do you think the fact that telomerase hasn't been approved by the FDA would deter that person?  How much do you think such a person would pay for a few micrograms of telomerase?  Think a researcher who was guaranteed secrecy would sell a few for, say, a million dollars?

Finally consider this: researchers have now found that roughly 99 percent of all cancers use telomerase to enable them to replicate infinitely.  If researchers could find a molecule that would block telomerase from regenerating the telomeres, it would appear to offer a way to make cancer cells "mortal," like normal cells.  While it wouldn't eradicate a cancer, such a discovery would seem likely to produce longer survival times.

Well guess what:  The same team that discovered telomerase also found just such a blocking agent.  So did they start controlled animal trials, then on human volunteers to test for toxicity?  If you can find anything on this, let me know.


If you're skeptical about any of this, I don't blame you.  Unless you're in this field you haven't heard a word about it.  Most people think that if a story seems significant, but they haven't seen anything about it on the "news" or in the NY Times, it didn't happen.

But in this case Elizabeth Blackburn, Carol Greider, and Jack Szostaks were awarded the 2009 Nobel Prize in Physiology or Medicine for their work on telomeres and their discovery of the enzyme telomerase 24 years earlier.  Hard to claim that's a con.

Also: giving nanomolar amounts of telomerase to normal cells has already been shown to regrow the telomeres and allow cells to replicate far past the Hayflick limit. (https://en.wikipedia.org/wiki/Elizabeth_Blackburn)

So have none of the promising leads for either telomerase or the agent that prevents it from working panned out?  

Before the covid plandemic that would be the only reasonable explanation.  After all, most Americans would never imagine that the FDA would suppress such a significant avenue of research.  But with what you've seen over the past two years--specifically including the banning of Americans from obtaining the safe, FDA-approved drugs ivermectin and HCQ-- how many rational adults still think the FDA is honest?

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For those who like to research for themselves, here's an article from a government website from 2011 (so duh gruberment lackeys didn't flag this as "disinformation"):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3045570/

Telomerase is activated in fetal development, protecting telomeres from significant loss during this period of intensive cell division.  However, before birth telomerase is repressed in most cells.  All adult somatic stem cells appear to be capable of activating telomerase during tissue regeneration. However, these periods of activation are insufficient to prevent telomere loss.  The ability to produce telomerase also drops with aging and stress.

humans lose telomeric DNA at about 15–60 base pairs per year.  Studies in human cells in culture "point to a causal relationship between telomere loss and cell aging."

https://en.wikipedia.org/wiki/Telomere#Discovery

From "PubMed," a website run by National Institutes of Health, 1996
https://pubmed.ncbi.nlm.nih.gov/8706799/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810624/