In the 1990s Lee Sweeney made headlines with his 'schwarzenegger mice'
He soon received calls from multiple athletes in hope of a genetic performance boost
In 2008, an Olympic year, Lee Sweeney’s phone was ringing nonstop.
For a busy physiologist at the University of Pennsylvania’s Perelman School of Medicine, that may be expected, but the reason behind the calls wasn’t exactly run-of-the-mill.
The people on the other end of the line were athletes in search of a particular kind of fix: They wanted him to dope them – via their genes.
In the late 1990s, Sweeney made headlines because of his research on “Schwarzenegger mice,” which were up to 30% stronger than their average counterparts. Sweeney had been able to isolate the gene responsible for activating a protein – IGF-1 – that controls muscle growth and repair.
The main focus of his experiments was on how to limit the deterioration of muscles with age, but the results also appealed to athletes in search of a performance boost.
Word got out, however, that he was not interested.
Ahead of this year’s Commonwealth Games, which started April 4, Sweeney’s was not such a hot number for athletes in search of an unfair advantage – possibly because he is now an adviser for the World Anti-Doping Agency.
“At the beginning, when we first started publishing on this, we did get contacted by high-level athletes,” said Sweeney, who’s also director of the University of Florida’s Myology Institute. “These days, it’s mostly body builders and people desperate to increase their performance or abilities.”
Back then, gene therapy – defined as the technique of using and manipulating genes in order to treat or prevent diseases – wasn’t as established as it is today and wasn’t recognised as enough of a threat to be listed as a banned practice in sport. But it soon became known that gene therapies could one day be used for much more than disease.
Responding promptly to the possibility, in 2002, the anti-doping agency established “gene and cell-doping panels” of expert scientists to discuss how best to head off the problem.
In 2003, the organization banned “gene doping,” which it defined as the “nontherapeutic use of cells, genes, genetic elements, or modulation of gene expression, having the capacity to enhance performance.”
This new frontier of doping presented a simple and dark idea: What if there was a way for dopers to never be caught?
Now, almost 20 years later, the technology is has finally been used to treat patients with rare diseases – such as severe combined immunodeficiency, chronic granulomatous disorder, hemophilia, blindness, cancer and neurodegenerative diseases – by transferring missing genes into skeletal muscles, Sweeney said. “So because of that, it is now at a point where potentially it could be used by athletes.
“It could be done today in athletes if some company and government would put the resources (in) to make it happen,” he said.
Getting inside your genes
In the case of the “Schwarzenegger mice,” Sweeney used the classic method of gene therapy, in which he modified the animals’ DNA using a virus to deliver and insert the required gene that would make the mice stronger.
Genes are delivered into an organism using a “vector,” the most common being viruses, like that used by Sweeney, which have been modified to be safe and no longer cause disease. The vectors carry the desired gene into targeted cells and, there, unload the genetic material, which in turn instructs the organism to produce the protein the gene encodes.
One example of a protein well-known to athletes is erythropoietin, commonly known as EPO, which regulates the production of red blood cells in the body, increasing hemoglobin and oxygen delivery to tissues.
With the injection of external EPO, elite athletes – often cy