How does gene doping work? Gene therapy is an experimental medical treatment. Typically, an individual with a malfunctioning gene has that gene replaced by a working copy of the same gene. Usually, this involves highjacking a modified virus to get the edited gene into the right cell type to be useful. The problem is that these approaches are extremely difficult, potentially dangerous and still under development — at least if they are to be fully tested and safe. Successful gene therapy may be only days away, but more likely it is still years away.
How would we detect gene doping? A year later, they created the Gene and Cell Doping Expert Group tasked with studying advances in the field, methods of detecting gene doping, and overseeing WADA research on the topic. Until recently, it was thought that tests for gene doping would need muscle biopsies; but Australian researcher, Anna Baoutina, has recently announced that her team can detect EPO gene doping with only a blood sample.
If a simpler, less invasive, test such as this can be fully verified, it seems likely that WADA will introduce it to their arsenal. Other, similar tests will undoubtedly follow. What are the risks? Clearly, gene doping would amount to cheating, making for an uneven and unfair playing field.
While viruses have spent millions of years evolving ways to get into our cells, we equally have been evolving ways to stop them. Indeed, poorly executed gene therapy could make us sick — like any other viral infection — or worse.
Balancing act: can we level the playing field? Elizabeth Parrish of the anti-ageing company BioViva claims to have given herself two kinds of experimental gene therapy, one of which blocks the breakdown of muscle tissue.
Nonetheless, you can be certain that BioViva is already getting calls from sportspeople desperate to try it themselves. Gene therapists working on treatments that could help athletes say they often get such calls. There have yet to be any confirmed cases of athletes genetically enhancing their bodies.
But this could be because none have ever been tested. Sports authorities are certainly taking the prospect seriously. Last week the International Olympic Committee said that samples from athletes competing in Rio will be tested for gene doping.
If you find cells with these extra genes, that athlete has been gene doping. Higher levels of red blood cells give endurance athletes a big advantage. Blood samples from Rio will be retroactively tested once the test is validated, and anyone testing positive will face the same penalties as with conventional doping. Far from it. The only way to detect them would be to remove a chunk of muscle from athletes, which is obviously unacceptable. It will be much harder — and much more expensive — to detect such changes and show they are due to doping.
Epigenome editing could be even more useful for treating diseases than genome editing. By transferring additional copies of genes coding for EPO, cells can be manipulated to overexpress the EPO gene and therefore produce more of the hormone. Instead of introducing entirely new copies of a gene in the manner described above, it is also possible to tweak the DNA around that gene to tune its expression level up.
In other words, without inserting any new copies of a gene, the cell produces more of the RNA transcript. For example, in a study on mice, 6 researchers edited a non-coding section of the mouse genome by inserting a sequence of DNA that increased the expression of the existing IGF-1 gene.
Indeed, a Chinese scientist recently claimed that he has created the first gene-edited babies, using CRISPR to disable a gene that allows the HIV virus to infect cells — which caused significant backlash globally.
Example method 2: decreasing abundance of performance-limiting gene products. In contrast to the genes referred to under example method 1 above, there are genes whose expression might impede athletic performance — so by removing or reducing the cellular abundance of the products of these genes, athletes might be able to break the limits on their performance. The gene encoding the protein myostatin — a negative regulator of muscle growth — is one such example. Indeed, a deficiency of myostatin in humans and animals can lead to dramatic increases in muscle mass.
As an example of the effect of this approach, researchers introduced molecules into mice which cut and degraded the RNA transcripts which otherwise would have resulted in the production of the myostatin protein.
Those athletes who succumb to the pressure to dope risk both a being caught and banned with catastrophic effects on their career , and b seriously and permanently damaging their health — these factors are explored further below.
If gene doping is detected, the default ban is four years. However, the detection of gene doping is not so simple, and this would likely be part of its appeal to would-be dopers.
An example of a challenge that anti-doping organisations face in this respect is that proteins resulting from gene doping can be very similar, if not identical, to those produced naturally. Even if proteins resulting from gene doping are not identical to their natural counterparts, they may not make their way into the urine and blood, which are the sample types traditionally used in doping control testing.
In short, WADA will face many such challenges if gene doping becomes a reality. The majority of gene therapy techniques being developed are for the treatment of potentially fatal diseases where the tolerance of potential side effects and risks may be high. However, history tells us that potential side effects and risks may not necessarily put off those determined to use prohibited methods in the pursuit of sporting glory.
The potential health risks of gene doping will depend on the technique used and the gene s targeted. However some examples of those risks are described below:. These are just some of the health risks associated with techniques developed by reputable laboratories for legitimate purposes.
If gene doping does become a reality, the gene doping products produced and supplied by unregulated and unaccountable underground laboratories are likely to present even more risks. That said, progress is being made and the relatively short list of gene therapies approved by the FDA is getting longer.
Barton-Davis ER, et al. Viral mediated expression of insulin-like growth factor I blocks the aging-related loss of skeletal muscle function. Lee Sweeney, Gene Doping Expert. Zhou S, et al.
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