RespiteMatch.com Health Blog

BY DELTHIA RICKS
STAFF WRITER

Obtaining lines of coveted embryonic stem cells without destroying the embryo has been a “holy grail” of scientists, and now separate teams say they have found ways of addressing such a goal.

While the work of both teams is preliminary, and tests have focused on mice, each group has proved — at least in principle — that stem cells can be produced effectively without destroying an embryo.

Reporting today in the journal Nature online, scientists at Advanced Cell Technology in Worcester, Mass., and another team at the Massachusetts Institute of Technology, have developed methods to produce stem cells, side-stepping thorny ethical issues that have overshadowed stem cell research.

Dr. Robert Lanza, vice president of medical and scientific development at Advanced Cell Technology, said in an interview that his technique not only is a first in biological research, it is a method that would allow an embryo to implant and develop into a healthy fetus — even after viable stem cells are extracted.

“No one has ever done this before,” Lanza said. “What we are trying to do here is to create a stem cell line without injuring an embryo. Our cells can go on to become a healthy, kicking baby.”

“It’s cool science,” said Larry Goldstein, a professor of cellular and molecular medicine at the University of California in San Diego. “It broadens the debate. But it will solve problems for some, and make problems for others.”

Scientists have long known stem cells can develop into virtually any kind of tissue. However, no one has conducted clinical studies showing whether stem cells actually will help sprout new nerves or beating-heart cells in patients suffering devastating diseases. But it is very likely, some scientists say, that stem cells may not have potent effects when used therapeutically.

Additionally, scientists also know that to be exploited therapeutically, stem cells must be derived from embryos at a critical stage: before the embryo implants in the uterus. To gather cells at this developmental juncture means destroying the embryo. And therein lies a raging ethical debate.

But Lanza said he has circumvented that concern — at least in mice — by adopting a technique commonly used in human in-vitro fertilization clinics. He and his team removed a single cell while mouse embryos were at the eight-cell stage of development and obtained a line of stem cells from that single cell.

Plucking a single cell at this stage is routinely performed in human embryos in assisted-reproduction clinics to check for birth defects.

“Many people including President Bush are concerned about destroying life to save life. But this is not destroying life because the embryo is fully capable of implanting,” Lanza said.

In assisted-reproduction clinics the single cell removed from embryos impairs neither the implantation nor the fetuses that develop from the cells. “I still recognize there are people who will have problems with this. But looking at what this means for the future that people — children and families — can be helped is something to look forward to. Most of us, I believe, will sleep more easily knowing that embryos do not have to be destroyed,” Lanza said.

MIT’s Rudolf Jaenisch, meanwhile, has obtained viable stem cells — also from mice — by creating cloned mouse embryos that are inherently incapable of implanting and developing. The method involves inhibiting formation of a critical embryonic cell layer called the trophectoderm, which prevents embryos from attaching to the uterine wall. The MIT team achieved this by blocking a critical gene in the mouse embryos. But while the embryos are incapable of becoming mice, the bundle of cells were capable of producing a bounty of healthy stem cells.

“Our experiments are very clear,” Jaenisch said. “You inhibit this gene and you get a clone that has no way of ever implanting. But this clone can make embryonic stem cells.”

Both techniques won’t end the political and ethical debate over the federal funding of embryonic stem cells, UCSD’s Goldstein said. The Dickey amendment, passed in 1996, prevents the use of federal funds for embryo research that would subject the embryo to any risk of harm.

Staff writer Jamie Talan contributed to this story.
Copyright 2005 Newsday Inc.