Cancer breakthrough!

Originally posted by sardion2000

There IS a cure.

Care to post a source on that? Also I'm sure you know that Cancer is not one disease so talking about a singular cure is rather inane.

There are many forms of cancer. You are asking the quoted person for proof 'there IS a cure'... How about some proof that there ISN'T one singular cure for all cancer types? Until we know there is not one cure for all cancer types, we shouldn't say such a thing is inane.

Thanks for posting those links soficrow, and I did read what
Marg said its just I wanted to know a little more about it since this is the first I have heard about it, and I had no idea it had been out this long, but the point is if telomerase is something ecential to cancer cells then we should target treatment and cures on destroying that. Although we probally are targeting telomerase this is the first I have heard about! But hey the longer we have know about it the closer we are to understanding it and getting a cure right? Well I sure have had an enlightening day now.

Originally posted by JoJo the religious man
Thanks for posting those links soficrow,
...But hey the longer we have know about it the closer we are to understanding it and getting a cure right? Well I sure have had an enlightening day now.

You're welcome JoJo.

If you are still interested - there is MUCH more to the telomerase story...


Healthy chromosomes end in "telomeres." These telomeres get shorter each time a cell divides, and as the telomeres get shorter, the cell ages.

But sometimes, cells don't age - they are "immortal." Immortal cells all have an enzyme called telomerase activated to keep their telomeres long.

Telomerase is found in fetal tissues, adult germ cells, and tumor cells (cancer). In cells where telomerase is NOT activated, the cells age and so does the body. If telomerase IS activated, then the cell continues to grow and divide - it becomes "immortal."

So telomerase and the "immortal cell" theory is important in two areas of research: aging and cancer.

Are Telomeres the Key to Aging and Cancer?

If telomerase makes cancer cells immortal, could it prevent normal cells from aging? Could we extend lifespan by preserving or restoring the length of telomeres with telomerase? If so, does that raise a risk the telomerase also will cause cancer?

Scientists are not yet sure. But they have been able to use telomerase to make human cells keep dividing far beyond their normal limit in laboratory experiments, and the cells do not become cancerous.

If telomerase could be used routinely to "immortalize" human cells, it would be theoretically possible to mass produce any human cell for transplantation, including insulin-producing cells to cure diabetes patients, muscle cells for muscular dystrophy, cartilage cells for people with certain kinds of arthritis, and skin cells for people with severe burns and wounds.

This is why Geron does not just hold the patent for telomerase, but also a huge range of patents for nuclear technology and stem cells - it's a strong business position. Geron basically controls the market in anti-aging, degenerative disease, and anti-cancer therapies and vaccines related to telomerase.

Using telomerase medically involves tissue engineering, cloning and more. The fact that it involves stem cells and cloning is one reason the cancer vaccine and other important medical products have been held up.



FYI - some telomere and telomerase basics:

What are telomeres and telomerase?

To make sure that information is successfully passed from one generation to the next, each chromosome has a special protective cap called a telomere located at the end of it's "arms". Telomeres are controlled by the presence of the enzyme telomerase. (animation)

Telomere activity is controlled by two mechanisms: erosion and addition. Erosion, as mentioned, occurs each time a cell divides. Addition is determined by the activity of telomerase. (animation)

Telomerase is found in fetal tissues, adult germ cells, and also tumor cells. Telomerase activity is regulated during development and has a very low, almost undetectable activity in somatic (body) cells. Because these somatic cells do not regularly use telomerase, they age. The result of aging cells is an aging body. If telomerase is activated in a cell, the cell will continue to grow and divide. This "immortal cell" theory is important in two areas of research: aging and cancer.

***

Telomeres

Each eukaryotic chromosome consists of a single molecule of DNA associated with a variety of proteins. ...The DNA molecule of a typical chromosome contains
* a linear array of genes (encoding proteins and RNAs) interspersed with
* much noncoding DNA.

Included in the noncoding DNA are
* long stretches that make up the centromere and
* long stretches at the ends of the chromosome, the telomeres.

Telomeres are crucial to the life of the cell. They keep the ends of the various chromosomes in the cell from accidentally becoming attached to each other (e.g., by nonhomologous end-joining).

***

Telomeres and Cellular Aging

Telomeres are important so their steady shrinking with each mitosis might impose a finite life span on cells. This, in fact, is the case. Normal (non-cancerous) cells do not grow indefinitely when placed in culture.

Could shrinkage of telomeres be a clock that determines the longevity of a cell lineage?
Evidence:
Some cells are immortal.
* the cells of the germline (the germplasm);
* unicellular eukaryotes (like Paramecium);
* some cancer cells.

It turns out that these cells are able to maintain the length of their telomeres. They do so with the aid of an enzyme telomerase.

***

Telomerase

Telomerase is an enzyme that adds telomere repeat sequences to the 3' end of DNA strands. By lengthening this strand DNA polymerase is able to complete the synthesis of the "incomplete ends" of the opposite strand.

Telomerase is generally found only in

* the cells of the germline, including embryonic stem (ES) cells;
* unicellular eukaryotes like Tetrahymena thermophila;
* cancer cells.


Also see: Telomerase and Cancer; Telomerase and Transplanted Cells; Telomeres and Cloning

One major hinderance to the idea that telomerase may halt a body's aging is that is does indeed cease apoptosis, but not mitosis. I'm not saying you suggested this, sofi, I'm just saying it's a reasonable doubt to have about the viability of using telomerase as an anti-aging treatment. Until we can find a way to rectify these two processes, there's no usefulness in telomerase in the field of anti-aging.

~MFP

Originally posted by bsl4doc
One major hinderance to the idea that telomerase may halt a body's aging is that is does indeed cease apoptosis, but not mitosis.

And that would be why it's linked to cancer, right?

But it seems that the process already is being manipulated successfully in tissue engineering, for example.

Do you know the status of cloning cells for transplant? And the role of telomerase in cloned cells? Ie., is telomerase activation/deactivation manipulated?

Do you know what the alternatives are to Geron's technology? Could that be the holdup? Looking for alternatives, to avoid paying intellectual property and patent rights?


.

And that would be why it's linked to cancer, right?

But it seems that the process already is being manipulated successfully in tissue engineering, for example.

Do you know the status of cloning cells for transplant? And the role of telomerase in cloned cells? Ie., is telomerase activation/deactivation manipulated?

Do you know what the alternatives are to Geron's technology? Could that be the holdup? Looking for alternatives, to avoid paying intellectual property and patent rights?

As far as the link to cancer, yes. To an extent, some oncologists (like the one I am working under right now) feel it is the CAUSE of cancer. Perhaps the enhancer/promoter which initiate the nuclear RNA transcript that eventually translates into telomerase is an oncogene that can be triggered by certain types of viral infections, radiation exposure (UV), chemical exposure, or other carcinogens. The cells found in a cancerous tumor, as you well know, are stuck in a cycle of constant karyokinesis and cytokinesis. These cells do not die, easily at least, but can also pretty much kill themselves to an extent by dividing beyond their nutritional means. This is compensated for when blood vessels re-route themselves to feed the tumor, but were it not for this, the outer tumor cells would die shortly after their creation due to division because of a lack of nutrition. Thus, if telomerase were suddenly activated in every cell in your body, or even just one cell subtype, you would experience a period of massive cellular increase (imagine, for example, the basal cells of your skin doubling in number due to telomerase not allowing the upper layer skin cells to die), followed by the massive death of cells due to a lack of immediate nutrition.

This process can most definitely by changed in tissue engineering. You can grow up telomerase+ cells in culture containing nutrient broth, but this is a far cry from introducing telomerase into a living system in which nutrient have to be transported TO the cells.

As far as cloned cells for transplant, I don't believe telomerase is an issue in these. From my understanding, and I am not in biomedical research, just clinical, the cells that are cloned are simply created by introducing a somatic cell nucleus of the patient into an anucelated egg cell from a donor, thus producing genomically competent stem cells which can be induced into cardiac tissue, neural tissue, etc. This is what Dr. Suk was doing in Korea, and sucessfully did with two lines, before falsifying the other 9 lines, due possibly to time/funding constraints or just poor moral judgement.

As far as Geron, it very well could be that they are trying to avoid having to pay for intellectual rights. A case I've heard of happening several times in medical corporations is that a company will purposely produce a treatment cheaper or easier than their brand name treatment, that way they can come off as a company who "care about the common man" by producing a cheap medicine, but the money all goes to the same place. This example I heard of was in Poland, and probably occurs in the USA, too. Doesn't quite work in social medicine due to the budget constraints, but I could see how even some less socialized states could fall into this.

~MFP

[edit on 3/2/2006 by bsl4doc]

Originally posted by bsl4doc

Thus, if telomerase were suddenly activated in every cell in your body, or even just one cell subtype, you would experience a period of massive cellular increase (imagine, for example, the basal cells of your skin doubling in number due to telomerase not allowing the upper layer skin cells to die), followed by the massive death of cells due to a lack of immediate nutrition.

I really would like to see an animation illustrating that process.

This process can most definitely by changed in tissue engineering. You can grow up telomerase+ cells in culture containing nutrient broth, but this is a far cry from introducing telomerase into a living system in which nutrient have to be transported TO the cells.

Right.

...Which is why it's used in tissue engineering but not introduced into a complex living system.

But - how is the telomerase deactivated? Is there any possibility that process could be modified to work in vivo (in a living body)?

As far as Geron, it very well could be that they are trying to avoid having to pay for intellectual rights.

What I mean here is that Geron owns the rights, pretty much across the board. So any researchers who use telomerase and the related technologies must pay Geron licensing fees. This creates an economic barrier to research - and may be holding up progress in the area.

Licensing costs are largely responsible for holding up production on bird flu vaccines for example - the new technologies are almost essential, but the licensing fees mean that the manufacturer loses a big chunk of profits. It's not financially attractive for companies to manufacture the vaccines - so they don't.


Great response. Thanks.

Would be good if you could dumb it down just a tad tho. Maybe add links for definitions? It's tricky to write for a broad range of backgrounds, but best not to presume familiarity...


.

Sorry for all the technical material. I'm actually sitting here at the hospital working on patient case histories for a research paper on autoimmune diabetes. ATS is a good distraction from work .

The idea you bring up about deactivating telomerase is an interesting one. I'm not sure as to which specific gene, or genes since it is most likely a complex protein, codes for telomerase. I assume that researchers somewhere have not only found the protein, as you pointed out, but perhaps have found the genetic material responsible, as well. The problem arises with one specific type of genetic element called an enhancer. An enhancer is a region of DNA which, as its name implies, enhances or activates a genetic sequence called the promoter. The promoter, aptly named, promotes coding of the actual RNA transcript which will later become the protein. As long as the enhancer is stimulating the promoter, you are getting telomerase protein. The problem with enhancers is two-fold: 1) enhancers don't have to be anywhere NEAR the gene in order to work, just on the same chromosome, and 2) some genes are in autostimulatory enhancer cycles, meaning once they are activiated just ONCE by a transcription factor which activates an enhancer for that gene, the gene itself will produce a transcription factor which activates another enhancer which will ALSO activate that same gene. Thus, the gene becomes stuck in this cycle of producing it's own stimulatory molecule (thus, autostimulation). I have a feeling we will find out later that there is an autostimulatory element to the telomerase gene or genes.

Finally, another big problem with telomerase is a mechanism called DNA methylation. Cytosine, one of the four nucleotide bases of DNA, can by methylated to become 5'-methylcytosine. This permanently condenses the methylated region of DNA, thus making transcription impossible. It may be that in cancers, some critical enzyme is not being produced due to improper methylation of the DNA. The reason I mention this with respect to cancer is that DNA methylation, unlike other forms of DNA regulation, is passed down to all progeny of the originally methylated cell. So, if one of your skin cells were to become methylated at the gene that codes for something like MHC-I, an immunological response protein, then ALL skin cells deriving from this original cell would have a methylated region at this gene. Interesting, huh?

~MFP

P.S. I'm working on making some rudimentary illustrations for these ideas right now, will let you know if I get them finished and posted somewhere. I'm no artist, so I hope you like MS Paint, hehe.

Ok, Soficrow. Here's the link to the images I put up...I'm not sure if the links work, I've never been good at making websites or anything. If you want, I can e-mail them to you or something like that, or you could maybe give me a website I can upload them to easier. Whichever.

geocities.com...

~MFP

Cool drawings. Thanks.

...My obsession with animation/special effects has to do with the idea of using film and other popular media as an education tool. Not that I'm tapped into the industry - I just think that way. ...People don't understand science so it needs to be packaged a part of entertainment, ala Jurassic Park etc. IMO - somebody's gotta do it...


Have you thought any further on economic barriers to research, and by extension, to socialized medicine? ...My experience in Canada is that the medical system provides the equivalent of a very basic private insurance package - and not much is covered, really. Granted, I get MRI's, angio's and the full range - but really, it's all geared to late stage interventions not preventive treatment. ...New medications for 'rare diseases' are not covered for example; essential expensive diagnostic tests are NOT conducted until symptoms are acute (which precludes prevention); etc...

...I am concerned that we shouldn't hijack this thread - but would love to continue discussion on socialized versus private medical systems - and to critique the processes and systems. ...If you don't want to start the thread, I am happy to do it. Would you please u2u me if you're interested?

ciao

It could be that I'm just fluey and tired, but...

I just did a quick pubmed search for +telomerase +inhibition OR deactivation. - 5518 articles listed - clicked on the third one - don't see the relevance, need a translator...

We report time-resolved fluorescence data for the anion of p-hydroxybenzylidene dimethylimidazolinone (p-HBDI), a model chromophore of the green fluorescence protein, in viscous glycerol-water mixtures over a range of temperatures, T. The markedly nonexponential decay of the excited electronic state is interpreted with the aid of an inhomogeneous model possessing a Gaussian coordinate-dependent sink term. A nonlinear least-squares fitting routine enables us to achieve quantitative fits by adjusting a single activation parameter, which is found to depend linearly on 1/T. We derive an analytic expression for the absolute quantum yield, which is compared with the integrated steady-state fluorescence spectra. The microscopic origins of the model are discussed in terms of two-dimensional dynamics, coupling the phenyl-ring rotation to a swinging mode that brings this flexible molecule to the proximity of a conical intersection on its multidimensional potential energy surface.
Deactivati on mechanism of the green fluorescent chromophore. J Phys Chem B Condens Matter Mater Surf Interfaces Biophys. 2006 Mar 9;110(9):4434-42. Gepshtein R, Huppert D, Agmon N. Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel, and Department of Physical Chemistry and the Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel. PMID: 16509746

This 1999 article supports your observations, but I'm looking for something more recent:

Studies of the molecular mechanisms in the regulation of telomerase activity

[edit on 3-3-2006 by soficrow]

Hey Sofi, good to know the drawins helped some. I'll try to wade through the article summary you posted here and translate a bit, heh.

We report time-resolved fluorescence data for the anion of p-hydroxybenzylidene dimethylimidazolinone (p-HBDI), a model chromophore of the green fluorescence protein, in viscous glycerol-water mixtures over a range of temperatures, T. The markedly nonexponential decay of the excited electronic state is interpreted with the aid of an inhomogeneous model possessing a Gaussian coordinate-dependent sink term. A nonlinear least-squares fitting routine enables us to achieve quantitative fits by adjusting a single activation parameter, which is found to depend linearly on 1/T. We derive an analytic expression for the absolute quantum yield, which is compared with the integrated steady-state fluorescence spectra. The microscopic origins of the model are discussed in terms of two-dimensional dynamics, coupling the phenyl-ring rotation to a swinging mode that brings this flexible molecule to the proximity of a conical intersection on its multidimensional potential energy surface.

I am by no means a geneticist, but from what I can discern from this article, it seems like they are studying the action of single promoter versus multi promoter systems. The green fluorescent protein (gfp) is the most common genetic marker used in science right now. Basically, it's a gene from a jellyfish (I think vittorius something...) that is spliced into a target gene, and then when subjected to UV light, it lights up neon green if that gene is being transcribed and translated. It seems that they are attempting to study the kinetics of the protein in this article by studying the emergence and intensity of fluorescence due to gfp.

~MFP

Thanks doc.

Sorry I've ignored you. ...To be honest, my interest in telomerase and related technologies is only peripheral - and I can't spend much time on it right now. I could be distracted by a thread on the "business of medicine" though.

If people did some research, they'd find out some interesting articles about cancer. Cancer loves sugar. Cancer hates O2. That's at the simplistic level. There are some simple ingredients that promote oxygenation of cells in the human body. You want cancer? Keep eating sugar and the rest of the crap out there. I believe that attitude also is a major contributor to disease.

My rule is this. Whatever I hear on the TV, do the opposite. Eggs are bad, no wait, eggs are good, no wait, eat the yokes, yokes are bad. No wait the whites are bad.

People are so brainwashed in this country by the government and media. I'll tell you something else. Now, in this day and age, is a great time to have cancer. There are a lot of survivors out there that didn't succumb to the doctors "guessers" advice to go on chemeotherapy and are survivors, and their body didn't have to get reduced to a prune to become a survivor. I agree with the above mentioned post. It is not profitable to cure cancer.

However I know that cancer is easily curable.

Kevin

Soo...despite the fact that there are easily thousands of studies showing that low to mid dose chemotherapy extends the life of cancer patients, you are going to say you know better than the doctors. You, the person without a medical degree, who has not worked with cancer patients' treatment, who has not performed chemotherapy research, and would have to do an internet search to tell me two chemotherapy drugs, YOU are going to say you know better than oncologists who spend their entire career trying to better treat cancer?

Wow.

~MFP

Hmmm.

Doctors provide cancer therapy knowing full well that the treatments are toxic. Such medical decisions are based on a risk benefit analysis - when the benefits of treatment are considered to outweigh the risks.

The writer above seems to be saying either that the risks do NOT outweigh the benefits - or that patients need to be MUCH more fully informed about the real risks...


.

Doctors are always (supposed) to weigh benefits and risks with every treatment, no matter if it's chemo or not. Most often, chemo is advised in young or otherwise healthy patients, but not given to older patients except very weak drugs in l ow doses which more often are not effective. I'm not sure why the poster above feels so maligned against the drugs or doctors who administer them. Perhaps a bad past experience. Who knows.

Originally posted by William One Sac
I read in the newspaper yesterday that researchers had found that eating sauerkraut regularly reduces your chances of getting many types of cancer.. The article said that it reduced the odds to more than a 70% reduction in people who get cancer masses. I will try and see if I can find the article to link to.

[edit on 2-16-2006 by William One Sac]

you serious, I eat the stuff on a daily basis, suprised I still have a gut.
goes good with smoked sardines

good to know.