The cheating gene: Will athletes go to the next level?
As we count the medals our wonderful Paralympians have won and feel a golden glow, as if we had done the hard work ourselves, the World Anti-Doping Agency (Wada) is wondering from where its next challenge will come.
Did Lance Armstrong really cheat and could Nadzeya Ostapchuk really have been so naive or was it her coach? Well, now we know! I did notice how keen the officials were to keep winners, especially in explosive events, away from the crowd and give them a package which I assumed was a urine sample receptacle and declaration.
Anabolic steroids, blood doping, EPO, what next? Gene doping - “the non-therapeutic use of cells, genes, genetic elements or the modulation of gene expression having the capacity to enhance athletic performance”.
This has been banned since 2003. Gene therapy has the potential for great benefits in the correction of faulty genomes (a genome is the full gene complement of an organism) where they are involved in the transmission of chronic and/or fatal illnesses between parent and child.
How long before we are all carrying a complete printout of our genomes with sickness potentials stated? The insurance industry would love this because it would give them credible grounds to refuse to insure or not pay out if you had hidden known facts.
Gene therapy, even with full medical support, is not easy, but in the form of gene doping where there is need for clandestine activity, it becomes very difficult - so far!
The delivery of the exogenous (outside the cell) genetic implant into a sufficient number of cells is needed to produce efficient gene expression.
Key among required supporting elements is the promoter, which is a short section of genetic material which tells the gene expression machinery of the cell where and when to start reading the instructions and how much RNA to make. Some genes are expressed in particular organs at certain times in the life of the organism. Others change quantitatively depending on the stimulus, for example those producing muscle protein.
DNA alone is not easily taken up by cells, so specific delivery methods have to be devised.
Perhaps surprisingly, modified viruses are the most promisingly effective vectors to carry DNA into cells.
Viruses are made safe by removing their own viral genes and then used as therapeutic or doping vectors when their DNA is replaced by a chosen gene which will modify the new host cell's metabolism.
Experiments with transgenic mice have shown that genetic modification can enhance endurance capabilities by 25 times. Also, if exogenous DNA can be introduced into skeletal muscle it can become part of the latter via the constant replacement and repair process.
Superficially, it still seems “easy and likely” but preliminary experiments with small mammals highlight the genetic diversity among mammals, and therefore humans, meaning that the reliability of one recipient responding the same as the next is, as yet, very unsure and hazardous.
It is important to remember that at the top level of athletics, and other sports, even a 1 per cent improvement could make all the difference and therefore justify the risk. This is especially so in these days of professional sport when many participants have only that sport on which to rely for livelihood.
“Currently there is no evidence that gene doping has been attempted.”
I take this statement with a very large grain of salt because gene doping would have to occur long (years) before the modified metabolic effect was required.
Further, currently detection would be inferred from either performance changes or detectable metabolites. Blood and urine samples would be replaced by biopsies which could be regarded as more invasive and would, I'm sure, raise many ethical issues, not to mention chances of infection.
On the other side of the coin, the beneficial effects for athletes are not guaranteed, nor can the myriad safety problems be reliably prevented.