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