1) Time until use in humans: 6 months to 50 years. Probably anyone's guess... Would suggest that the likely path once this research has been vetted would be to trial in medical conditions known to be associated with short telomeres such as Werner Syndrome, Ataxia Telangiectasia and others before being more widely adopted if this proved both safe and effective in humans.
2) The gene in question is conserved between humans and mice so yes, theoretically any therapy which induces telomerase in mice will do so in humans as well. [1] -
3) medically speaking the downsides are mostly 'unknown unknowns' - but some of the known unknowns are - what are the chances that the virus may integrate with the host genome? If this happens what are the chances it causes cancer? What are the risks of an immune reaction? What are the chances of mutation?
It would seem that many of these risks are not borne out by the murine trial but it would remain to be seen.
- I Should point out that (2) may convey the impression that they are upregulating the existing cellular gene to achieve this outcome: they are actually ntroducing one on the virus. In my opinion this is may be less effective than being able to eventually upregulate the gene in all cells as a virus is unlikely to get to all 10^13 (approximately, give or take an order of magnitude) cells in the human body. It could be that the 24% and 13% rates of lifespan increase (representing treatment at approximately middle age and old age respectively) may be due to the down-chain propagation of those cells that received the treatment and that more effectively delivering the virus or activating telomerase may result in better increases. However this is just my opinion and at the moment my University journal access is under maintenance so I can't read the paper
Constant telomerase activation is one of the major steps in making cancer cells immortal and thus eventually metastatic. It's possible that controlled telomerase activation (via drugs or clever future gene therapies) might present a small enough increased cancer risk that it would be worth the increased health and longevity.
Last I heard, gene therapies currently have fairly high risks involved with them (cancer, mostly).
Blasco also published in Rejuvenation Research last year about a dietary supplement that activates telomerase. So, that + this makes for some interesting reading.
Unfortunately, all of these original articles are behind a paywall. Most of us here have some University access, I believe, but not all. Science Daily at leasts gets you the gist.
I used to read Sciencedaily everyday but it's mostly unverified bullcrap reporting press release type of claims without criticism. They always report sensational discoveries but actually nothing every comes past the headlines in the actual world.
Does the therapy used to treat the mice with these genes work with humans?
What could the possible downsides of this be (other than things like overpopulation)?