Update on Last Week’s Embryonic Stem Cell Study

August 28, 2006

Over the weekend there has been quite a bit of development regarding last week’s embryonic stem cell announcement. Briefly, Advance Cell Technology (ACT) of Worcester, Massachusetts published an article in the science journal Nature on Wednesday, August 23, 2006, purporting that they had let an embryo grow to the 8- to10-cell stage, extracted cells, and cultivated some of those cells into stem cell lines, without destroying the embryo. The article was criticized immediately for not showing what it claimed to show.

In fact, it has now become clear the that early media reports (apparently based on a press release by ACT) were simply wrong. The Washington Post on Saturday reported, “Nature corrected wording in a lay-language news release it had distributed in advance and posted clarifying data it had asked the scientists to provide.”

Much of the controversy surrounds the fact that it was not made clear in the original press release or in the early media coverage that all of the embryos used in the study were destroyed in the process of the study (the paper published in Nature did disclose this). The embryos used were at the eight-cell stage, and up to seven of the eight cells were used from each embryo, which destroyed the embryos.

Let me back up. It was originally reported that scientists had removed a single cell from an embryo, and used that cell to make a stem cell line. In fact, two separate experiments were conducted.

In the first experiment, researchers removed a single cell from an embryo, and the embryo was allowed to continue to grow and develop. It is a well-known scientific fact that a single cell can be removed from an embryo, and that the embryo can continue to grow and develop. So this experiment proved nothing new. What is not known are the long term effects of removing a single cell at this stage, and the experiment did not address that issue.

Second, multiple cells were taken from 16 embryos (a total of 91 cells) and in the end those cells yielded two stem cell lines.

The original press release sort of combined the two different experiments. To make matters worse, apparently the original article has a series of pictures of embryos that adds to the confusion.

Saturday’s Washington Post picked up on it with an article entitled, “Critic Alleges Deceit in Study on Stem Cells.” Newsweek also weighs in with “ Embryonic War: Scientists and ethicists put the latest stem-cell ‘breakthrough’ under the microscope.” Two choice quotes from the Newsweek article:

A more careful examination of Lanza’s work showed he’d only proposed a new method, but hadn’t in fact proved it worked from start to finish.

And

“We’re against manipulating, harming, assaulting embryos for their cells even if it doesn’t always kill them,” says Richard Doerflinger, of the U.S. Conference of Catholic Bishops.

Well said.

Wesley J. Smith does a great job of covering the saga in an article in The Weekly Standard. Smith also reminds readers that this isn’t the first time ACT has over-hyped the scientific discoveries of its researchers. In 2001, it was cloned human embryos (“The ACT report was quickly debunked by the science community”).

But why? The San Francisco Business Times reports, “Advanced Cell Technology raises money after stem cell news.”

The less cynical reason is that it is thought that embryonic stem cells are more flexible than adult stem cells (the technical term is pluripotent). However, there are now several peer-reviewed studies that have been published, which indicate that non-embryonic (or adult) stem cells are pluripotent. Two of the latest studies:

Ling T-Y et al., “Identification of pulmonary Oct-4+ stem/progenitor cells and demonstration of their susceptibility to SARS coronavirus (SARS-CoV) infection in vitro,” Proceedings of the National Academy of Sciences USA 103, 9530-9535, 20 June 2006.
Quote: “Lung tissue contains a pluripotent adult stem cell.”

Kucia M et al., “A population of very small embryonic-like (VSEL) CXCR4+SSEA-1+Oct-4+ stem cells identified in adult bone marrow,” Leukemia 20, 857-869, May 2006.
“Small Bone Marrow Stem Cell population expresses pluripotent genes Oct-4, Nanog, and others, and can form derivatives of all 3 primary germ layers”