Liver Buds Show Promise, but Growing New Organs is Still a Long Way Off

By: Rebecca Jacobson

Watch this time lapse video showing how three types of stem cells organized into a three dimensional liver bud over 72 hours. Video by Takanori Takebe

When stem cell biologist Takanori Takebe at Japan's Yokohama City University first saw his results in a petri dish, the feeling was hard to describe.

"I think 'gobsmacked' is the closest word in English," said translator Matthew Salter from the journal Nature's Tokyo office, during a press briefing on Tuesday.

Takebe and his team had mixed three cell types: adult stem cells engineered for a human liver, adult bone marrow stem cells and stem cells from a human umbilical cord. The cells self-organized into a liver bud -- a tiny, three dimensional, functioning piece of human liver, complete with a vascular system to deliver blood to the organ. When Takebe transplanted the liver bud into a mouse, it thrived, functioning like a human liver.

It also helped bring the mouse back from liver failure, an important step in the team's conclusion that the liver bud was functioning, Takebe told the press.

Creating fully functioning organs for transplant has been a goal of stem cell research since work on embryonic stem cells began in the 1980s. As of today there are 118,647 people in the United States on the waiting list for new organs, according to the US Department of Health and Human Services. Takebe's hope is transplanting hundreds of these liver buds could restore up 30 percent of a patient's liver function. This technique could work for other organs like the pancreas, Takebe said in his paper, and perhaps lead to creating a full liver.

The group's findings are published in this week's issue of the journal Nature.

Dr. Timothy Nelson, director of the Regenerative Medicine Consultation Service at the Mayo Clinic, says when studies like this come out, he gets lots of questions from families, hopeful that this means a new treatment for their sick loved ones. Not yet, he always cautions them. It can take 10 years for the proof-of-concept study in a lab to become a clinical trial -- and that's optimistic, he said.

"I spend a lot of time talking to patients about the hope and hype of stem cell biology," he said. "I try to leave them with the message that let's be hopeful, but as of today it's not possible to bring that to your patient."

See the rest here:
Liver Buds Show Promise, but Growing New Organs is Still a Long Way Off