From California to Spain: Growing Human Organs in Pigs

Juan Carlos Izpisúa Belmonte in Murcia, Spain, in 2015
El Mundo photo

The ongoing tale of pigs, people and their organs moved along during the weekend with a fresh chapter about a Spaniard and the Salk Institute in La Jolla, Ca.

Reporter Bradley Fikes wrote a lengthy piece in the San Diego Union-Tribune dealing with Juan Carlos Izpisúa Belmonte and his quest to grow human organs in pigs.

Izpisúa Belmonte has a lab at Salk and another in Spain. Fikes reported that the researcher received a $2.5 million award from the National Institutes of Health last week "to advance his research with monkey cells implanted into pig embryos."

Fikes wrote,

"Since monkeys are biologically similar to humans, analysis of pig-monkey chimeras should yield insights that can be applied to eventual production of human organs, he said. And unlike mice, pigs are large enough to grow usable human organs."

In Spain, Fikes said, Izpisua Belmonte is forging ahead at the same time with human-pig work.

The research is touchy for obvious reasons. But Fikes wrote that "the shortage of organs that causes nearly two dozen Americans — and many others around the world — to die each day while awaiting a transplant."

Izpisúa Belmonte is making progress, according to the newspaper report. Fikes wrote,

"After years of experiments, in 2015 his team reported success in coaxing a newly identified type of human stem cell to not only live in mouse embryos, but also integrate into the embryos’ structure. Those embryos weren’t allowed to develop further because of U.S. regulations."

Izpisúa Belmonte has received $6.5 million in three awards from the California stem cell agency, but none of those grants are currently active.  

Pigs and People: Growing Human Organs in Animals, Changes at the Federal Level

Last week's news that the federal government is moving to lift its ban on funding research involving human-animal hybrids is a bit of old hat in California.

The state's $3 billion stem agency has long been okay with such research and has well-established protocols to ensure that it is conducted ethically and safely.

Last year, the agency, formally known as California Institute for Regenerative Medicine (CIRM), reported (see below) on its activities to the National Institutes of Health, declaring,

"CIRM has reviewed twelve protocols at seven different institutions where stem cells or neural progenitor cells were introduced into vertebrate animals. CIRM found that all protocols were reviewed and approved by a SCRO(standards review) committee consistent with CIRM requirements."

The Chimera of Arezzo -- photo by Joe deSousa

The announcement that the NIH is once again likely to fund the creation of chimeras -- organisms composed of genetically different cells -- received a significant amount of attention in the media. But none of the stories noted the origin of the word in Greek mythology, where it signified a fire-breathing female monster with a lion's head, a goat's body and a serpent's tail.

Sara Reardon of Nature wrote,

"Chimeras are a growing area of research. Currently, researchers use them to study early embryonic development and to create animal models of human diseases. But one major goal is to engineer animals to grow human organs. The organs could later be harvested from the adult animal and used for transplantation into a patient."

Kevin McCormack, senior director of communications for CIRM, told the California Stem Cell Report, last April,

"On a purely theoretical level CIRM has no objection to growing replacement organs or tissues in pigs, provided it met all CIRM’s rules and regulations. We fund research that does that all the time with mice and rats. Right now none of the research we fund is being used to do that."

Shen Ding -- Gladstone photo

Lenny Bernstein wrote in the Washington Post that researcher Shen Ding at the J. David Gladstone Institutes in San Francisco and who has received $6.7 million in research funding from CIRM, sounded a note of caution.

"While he does not favor the current (NIH) moratorium, Ding said, he believes scientists in this field must move slowly because 'we don't know how to precisely control where and how [cells] might contribute' to different organs."

Bernstein noted,

"The NIH imposed its temporary ban on funding last September, citing ethical concerns. These include worries over animals whose brains might contain human brain cells and what might happen if chimeras were able — and allowed — to reproduce."

The NIH is accepting comments over the next several weeks and then is expected to move forward with its proposal, perhaps with changes.

For Hank Greely, a Stanford law professor, it's about time. Last spring, he wrote an op-ed piece in the Los Angeles Times and said, 

"Today we face the possibility of babies getting organs grown in human/nonhuman chimeras — beasts that are pigs except for a single human organ. To the uninitiated, this may sound more like the dark arts than modern medicine, but pursuing careful research and potential clinical use of these chimeras is both proper and important."

  CIRM Statement to NIH re Chimera Research by DavidJensen on Scribd

Growing Human Organs in Pigs? Time for California to Step Up?

Looking for a new heart? Need a new kidney? How about a pancreas?

All of those priceless human organs are in short supply. And a Stanford law professor says it is time to get moving on developing more of them.

In an opinion piece last week in the Los Angeles Times, Hank Greely said,

Hank Greely

"Today we face the possibility of babies getting organs grown in human/nonhuman chimeras — beasts that are pigs except for a single human organ. To the uninitiated, this may sound more like the dark arts than modern medicine, but pursuing careful research and potential clinical use of these chimeras is both proper and important.

"Every day about 30 Americans die because they can't get an organ transplant. Upward of 120,000 Americans are on transplant waiting lists. We are, medically, on the cusp of being able to save these lives in new ways: repairing failing organs with new genes or stem cells, building mechanical organs and growing replacement organs."

Greely pointed to a researcher at the Salk Institute in La Jolla, Juan Carlos Izpisua Belmonte. Greely said the scientist wants to "to grow a human pancreas in a pig to provide insulin-making cells for transplant into diabetics." Greely wrote,

"His research into how this can be accomplished is exciting but very early, yet even those preliminary steps have been threatened by a surprise moratorium announced last fall by the National Institutes of Health. NIH said it would not fund any research that involved putting human stem cells into earliest-stage nonhuman embryos. NIH said this wasn't a ban, but just a pause to consider the implications of such research and possibly to create a policy for it."

Greely did not mention it, but such research could be financed by California's $3 billion stem cell agency. In response to a question, Kevin McCormack, senior communications director for the agency, said,

"On a purely theoretical level CIRM has no objection to growing replacement organs or tissues in pigs, provided it met all CIRM’s rules and regulations. We fund research that does that all the time with mice and rats. Right now none of the research we fund is being used to do that."

The Salk scientist has already received $6.6 million in awards from the agency, but none of it involves growing people organs in pigs.

Greely noted that both California and the nation have an effective system for regulating such research and that the NIH should not be sitting on its hands. He said,

"That's no guarantee that human organs will grow in pigs, but we won't find out if Belmonte and others can't try."