July 18, 2011

Sierra Sciences working towards antiaging via Controlling Telomere Length


Telomere Length Therapy






Compounds such as these have very recently been discovered. One such compound is TA-65, a nutraceutical discovered by Geron Corporation and licensed to TA Sciences. Additionally, Sierra Sciences, using a robotically-driven high-throughput drug screening effort, has discovered over two hundred compounds in twenty-nine distinct drug families that induce the expression of telomerase in normal cells. However, the perfect drug hasn't been found yet. None of the compounds induce telomerase in large enough quantities that are likely to stop or reverse aging; even the strongest known compound, a synthetic chemical patented by Sierra Sciences but not approved for human use, induces only 16% of the telomerase expression found in some immortal cell lines. Also, many of these compounds (with the notable exception of TA-65) are somewhat toxic to cell cultures and probably unsafe for human consumption.

Finding a more powerful drug will require more screening and more research, and the speed of that progress is dependent almost entirely on the level of funding that the project can achieve.

In November 2008, scientists published a paper describing how they had created cloned mice from mouse cells containing the inserted telomerase gene, which continually produced the telomerase enzyme. These mice were shown to live 50% longer than cloned mice created from cells that didn't contain the inserted telomerase gene.

It's becoming increasingly clear that prevention of telomere shortening might be the best way to extend human lifespan beyond the theoretical 125-year maximum lifespan. How long this can extend the human lifespan is anyone's guess, but living a healthy, youthful life to 250, 500, or even 1,000 years is not outside the realm of possibility.

Although telomerase is necessary for cancers to extend their lifespan, telomerase does not cause cancer. This has been repeatedly demonstrated: at least seven assays for cancer have been performed on telomerase-positive human cells: the soft agar assay, the contact inhibition assay, the mouse xenograft assay, the karyotype assay, the serum inhibition assay, the gene expression assay, and the checkpoint analysis assay. All reported negative results.

As a general rule, bad things happen when telomeres get short. As cells approach senescence, the short telomeres may stimulate chromosome instability.9 This chromosome instability can cause the mutations normally associated with cancer: tumor suppressor genes can be shut off and cancer-causing genes can be turned on. If a mutation that causes telomerase to be turned on also occurs, the result is a very dangerous cancer.

Paradoxically, even though cells require telomerase to become dangerous cancers, turning on telomerase may actually prevent cancer. This is not just because the risk of chromosome rearrangements is reduced, but also because telomerase can extend the lifespan of our immune cells, improving their ability to seek out and destroy cancer cells.

It's fairly obvious that long telomeres in human beings are not correlated with cancer. If that were true, young people would get cancer more often than the elderly. Instead, we usually see cancers occurring in people at the same time they begin to show signs of cellular senescence - that is, at the same time their immune system begins to age and lose its ability to respond to threats. Extending the lifespan of our immune cells could help our bodies fight cancer for much longer than they presently can.

Popular Science - the Man who would stop time.

Nature - Telomere dysfunction induces metabolic and mitochondrial compromise



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