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Gene Therapy Ages Human Cancer Cells in Lab
mattr writes "Korean scientists are the first in the world to selectively age off and kill human cancer cells, by injecting a gene that suppresses telomerase, a cancer-specific enzyme that normally makes cancer cells immortal by protecting the telomere tips of their chromosomes. The telomere length modulation mechanism was found by two scientists from Yonsei University and colleagues at U. Central Florida, and is reported in the April 1 issue of Genes and Development magazine."
In Korea, only cancer gets old!
But seriously, this is very interesting. When telomeres started getting press a few years back, it was really obvious that this would eventually be the key to managing cancer. (And if Alex Chiu gets his way, the key to immortality).
If cells age because child cells of a mitosified cell contain fewer telomeres, then something that prevented that telomeric loss would lead to an eternal lifetime for splitting cells.
What has interested me about this is that babies are born with a full set of telomeres. This means that the telomeric levels of the parent (mother) is not passed to the child. All other cells in a person's body are dependent on the number of telomeres present in those first few cells clumped together in the womb.
By blocking fetal tissue research, the harvesting of these precious cells is hampered. The reasons for fetal research are many, and the study of telomeres is one big area that simply can't be replicated with non-fetal stem cells.
Inhibiting telomerase has a significant problem: it kills off the gametocytes, which need telomerase to reproduce constantly but still have constant length telomeres. The side effect has to be infertility, unless the researchers found a receptor or variation in cancer cells which allows selective target for the vector. I have a feeling that it is not what they did, since the cancer cells were grown in a tissue culture, and not in vivo. We'll have to wait for human studies to see where this is going.
This mechanism has been studied for a very long time, but this must be the first time that researchers have been successful in manufacturing the vectors.
Of course, there are still promising treatments such as angiogenesis inhibitors which has the benefit of not losing fertility.
I am defenseless. Use your button. Mod me down with all of your hatred.
What isn't clearly mentioned is that telomerase is *inactive* in normal human cells. We're born with our telomeres at a certain length, and they're never renewed. That's why some cancers are unique in that they reactivate this latent gene therebye making them immortal; for example, Hela cells are used in every lab across the country. They originally were taken out of some woman's breast cancer in the 50's and they're still thriving! As a matter of fact, while she's long dead, there's still several tons of her! But even if you were to turn off a reactivated telomerase gene, it is logical to believe that they would begin to age normally; ie, if the person with the cancer is in his 50's, the cancer might not die for several decades. The important thing to remember is that *every* cancer in every person is different on a molecular level. They are all unique, and that is why we'll never have a blanket cure for cancer. What we will eventually have is effective treatment for currently untreatable types, which is a different story all together.
If telomerase makes cancer cells immortal, is someone working on a way to make, uh, non-cancer cells immortal?
I know it sounds very progressive to make those sort of assertions, but they don't have much merit. Anyone with even a rudimentary scientific background will tell you that key scientific breakthroughs come from all over. As a matter of fact, in the past few years there has been a considerable amount of concern within the American scientific community over the lag in American research and publication. Research just isn't a priority anymore in America, and we are beginning to feel the effect.
My guess is that the Korean scientists will keep their credit, just like the Koreans scientists who recently successfully generated stem cells from somatic adult tissues, just like the Dutchman who came up with the microscope, just like the Moravian monk who counted peas, just like the Swede Botanist retained credit for the Linnaean classification, just like the Russian Chemist retained credit for the periodic table, just like 10th century Arabs retained credit for much of Algebra, just like citizens of Greek city-states retain credit for beginning to formalize reason.
The capacity for human genius is universal, and in the reality based community known as science, we appreciate that. It belittles the intellects of foreign researchers and the hard work of American scientists to say otherwise.
wow. I am glad to see some good news like this. I have a cousin dying of leukemia(sp?) who probably won't live through the weekend. She is 37 yrs old. she has 4 kids... the younger ones are 2 and 4.
At times like this it is hard not to get mad at the medical profession. On the other hand I have a great appreciation for what medicine has done for my family.
The cousin I mentioned got an extra year of life because of an experimental stem cell (no not the kind thats been in the news) transplant.
My father has had open heart surgery twice. He is 64 years old and still goes backpacking with my brother and I.
My mom, although a survivor has had cancer 3 seperate times: breast cancer in each breast and a melanoma in her eye.
It is from the latter that I gained a great respect for medical research, and it is why I smile reading a story like this article.
when she had her eye cancer there was a new experimental treatment at the UW hospital here in seattle. They cut her eye open and sewed a patch of radioactive material over the tumor. They then sewed the eye shut and sent her home for several days with a lead shield over her eye.
Then they took her back to the hospital and cut the eye open again and removed the patch. Over the course of the next year the tumor died back (we know because of the ultrasound and other tests they do on her). Now she has finally lost the last of the usefull sight in that eye. The sight-loss is due to the close proximity of the radiation treatment to the optic nerve.
The only other treatment at the time was to remove the eye completely. With the radiation treatment she got many years of good sight out of that eye she wouldn't have had.
It is funny to me that at the time that treatment seemed so high tech. now it just sounds barbaric. cutting the eye open twice... so invasive. Now this article highlights something that may, in our lifetime be the new exciting experimental cancer treatment, and our kids (if they can still afford health care) will wonder how we endured such brutal treatment (I would suspect no cancer treatment in our lifetime will be FUN anyway)
I guess my cousin's situation has me in an extra thoughtful mood tonight.
Obama is a twitter sock puppet
Yup, I can see it now:
Aide: Sir, have you looked at the bill on genetic research?
Shrub: Yes, and I vetoed it.
Aide: Um, why sir? It would have cured cancer?
Shrub: It said a side-effect of the research might be immorality, and I won't STAND for that!
Aide: (slaps forehead) No sir, it didn't say immorality, it said immortality.
Shrub: (looks confused)
I honestly hope some moderator mods this up fast. I'm a grad student working on this very thing so I'd like to hope I know something about it... When Dolly was first cloned we all thought telomeres were the key to keeping clones alive longer. So when Dolly was made as a clone the nucleus was injected into an oocyte that had telomerase activity that restored Dolly's telomeres (read: Dolly had normal telomeres). Yet Dolly displayed many diseases and phenotypes that old sheep normally would. The obvious conclusion, there are other factors that we don't know about that contribute to both aging and death. Please please please don't think telomerase is the key to immortality and the cure to cancers. Yes most cancers eventually gain telomerase activity but this isn't some magical target for immortality and cancer cures.