Thursday, March 11, 2010

TA-65 safety claims

Earlier I posted about TA-65, a telomerase activator, which some hope could reverse some of the effects of aging. Amiya Sarkar is a doctor in Calcutta who writes a fascinating blog on physiology and physics. He and I have emailed back and forth for a couple years now, starting with a very cool idea he had for an inexpensive open-source electrocardiogram. (One of these days we really need to get that project back on track.)

Amiya expressed the concern that any telomerase activator could be viewed as a potential cancer risk. Cancerous cells use telomerase to support the unlimited replication that characterizes cancer. The folks at Sierra Sciences openly recognize this concern, and give reasons why they believe it's a red herring, on this webpage:
In most cases (85–95%), cancers accomplish this indefinite cell division by turning on telomerase. For this reason, forcing telomerase to turn off throughout the body has been suggested as a cure for cancer, and there are several telomerase inhibitor drugs presently being tested in clinical trials.

So, anti-aging scientists must be out of their minds to want to turn the telomerase gene on, right?

No! 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...

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.
In support of this, they list several papers.
  • Jiang, X.-R. et al. Telomerase expression in human somatic cells does not induce changes associated with a transformed phenotype. Nature Genet., 21, 111–114 (1999)
  • Morales, C.P., et. al. Absence of cancer-associated changes in human fibroblasts immortalized with telomerase. Nature Genet., 21, 115–118 (1999)
  • Harley, C. B. Telomerase is not an oncogene. Oncogene 21(4): 494-502 (2002).
From other writings on their website, and from their postings to Twitter and Facebook, it's clear that the Sierra Sciences folks are 100% confident that telomerase activators pose zero cancer risk. They are in a much better position to know about this than I. But if I started taking TA-65 and they were somehow mistaken, they wouldn't be the ones at risk for cancer. I hope to find out about those seven assays and try to read those three papers in my abundant spare time, and maybe discuss the matter with my doctor. (My present circumstances do not permit me to afford TA-65 even if I decide I want it.) Wouldn't it be cool if the Sierra Sciences people turn out to be correct...

3 comments:

Mike said...

I just heard of TA 65 a few days ago (Nov 20 2010). I just got around to googling it today. Yikes, telomerase activator, protector, or what ever. The first thing I thought of was CANCER! It would be great if TA65 were actually effective and safe. But I would be VERY CAREFUL with it. Much of the mechanism of carcenogenesis is alterations in the expression and control of genes not just the genes (alleles), i.e. DNA base sequences themselves. Helping cancer cells live longer is probably not a good idea. As you know many possible cancer treatments being developed involve "helping cancer cells burn through their telomeres so they can no longer reproduce, i.e., you help cancer cells age fast". I have a degree in biology and have fair knowlege of molecular genetics. I would not base my faith on a technology from one source, I'd like to see research from many independant study's, DCD, FDA, Mayo Clinic, Harvard U. M.C., Stanford U. M.C., etc.

Will Ware said...

Sorry not to see your comment sooner. You're right to identify the possibly carcinogenic role of telomerase as the pivotal question in whether TA-65 is safe. Where does one look for an answer to this question? I think the studies I mentioned in the post (which I haven't yet read myself) are the best starting point.

One could hope to learn something by asking, where do the vested interests of Sierra Sciences lie? Bill Andrews (the CEO) wrote: Although TA Sciences, the distributor of TA-65, is technically a competitor of Sierra Sciences, the two companies have a close working relationship. It's our philosophy that we want a cure for aging to be discovered, even if we aren't the ones to discover it. That answer is a little muddy to me, so I think this is not a productive line of inquiry.

Helping cancer cells burn through their telomeres is great as long as it is limited to cancer cells. As with most things in cancer treatment the big question is selectivity. But that doesn't actually bear on the question of whether TA-65 is safe.

Chuck Calhoun said...

Will, Sierra Sciences has now jumped on board with another product that they feel is even better at as much as a tenth of the cost. If you are open to taking a look, I would love to get you some info on it.