The cloning of these GMO pigs with all their allegedly inactivated endogenous retroviruses, investors say, solves the main stumbling block to use these animals as an organ source.
But we can trust? Would you use a heart grown inside a GMO pig? What could go wrong? A lot, actually.
Among the various possibilities that current biotechnology poses for making organs for transplants, there is one that – including transplant experts – consider especially viable in the short term: using pigs as organ incubators.
But the problem is not using a pig or a goat or a cow, as sources of organs. They have all been used in the past. They have all been experimented on before.
As humiliating as it may seem, the pig is one of the animals most similar to us, even in physiological and metabolic aspects of great complexity.
Although the news of using pigs as sources of organs for transplants has been presented as a breakthrough, we all know is not so simple as taking an organ from a pig and sewing it on a human. In fact, it is rather complex.
The news has been received warmly by the medical industry as the possibilities for financial gain go through the roof. The “discovery” has swept one of the main stumbling blocks toward that goal of enormous medical interest.
A consortium of North American and Chinese scientists has generated pigs completely free of endogenous retroviruses, they say, a type of virus whose DNA is integrated into dozens of animal genome sites and that can be activated by transplanting the organs into humans. That possibility would have disastrous consequences.
Endogenous retroviruses have disconcerted geneticists for decades. Our own genome is plagued with residues of ancient retroviruses, and some are still active and jumping from one place to another during our development.
Pigs have 62 endogenous retroviruses, and their genes are functional, allowing them to jump from one place to another when porcine cells are surrounded by human cells, as would happen in the case of a transplant. Its deactivation is therefore essential.
There remain other important pitfalls, especially those concerning tissue compatibility. But scientists feel so optimistic that they hope to resolve them within a year, and already plan some preliminary clinical trials.
Eliminating the 62 endogenous pig retroviruses was impossible until very recently, scientists involved in the experiments say.
The key, as in many other biological problems, has come from the CRISPR technique of genomic editing, which allows them to modify any piece of DNA at will.
These are the people playing God with the human genome, the kind of games seen in science fiction movies such as
Scientists assure us that they have inactivated an essential gene for all retroviruses, best known as POL, which makes the enzyme that replicates the genetic material of the virus and integrates it into the host’s genome.
With all the POL genes inactivated in the 62 pig retroviruses, these potential infectious agents are left without the cornerstone of their life cycle, and are converted into a mere fossil residue of the porcine genome, scientists say.
To appreciate the seriousness of their intentions, a fact is enough: the Chinese group WH, the largest pig breeder in the world, created a bioscience unit in April to generate pigs for transplants. Watson, I’ve told you to keep track of the money.
Since clinical trials have not begun, there is zero proof that scientists have been successful in the splicing of the genes and in inactivating the retroviruses, as they claim they have. But either way, will anyone seriously consider implanting an organ grown in a GMO pig whose retroviruses might jump into human genes?