Tuesday, September 05, 2006

More on ACT embryonic stem cell study

Recall back on July 29, 2005 Senator Bill Frist emphasized that Bush's policy for federal funding of embryonic stem cells should be "modified" because "unexpectedly, after several generations" the cell lines have become "less stable and less replicative," and the existing federally funded cell lines are "also grown on mouse feeder cells, which we have learned since will likely limit their future potential for clinical therapy in humans."

The coverage by The Scientist included information about the use of mouse feeder cells that was in the Nature paper but was not in the ACT press release:

In their latest study, Lanza and his colleagues experimented on 16 unused embryos produced over the course of in vitro fertilization attempts. They used micropipettes to remove individual cells, known as blastomeres, from the eight-to-10-cell-stage embryos. Cells are already routinely removed from embryos during in vitro fertilization for preimplantation genetic diagnosis, a procedure that apparently does not harm the embryo.

The extracted cells were cultured together in the same medium, including mouse feeder cells. Out of 91 blastomeres, the researchers generated two stable human embryonic stem cell lines and 19 embryonic-stem-cell-like outgrowths.

[All of the single blastomeres were cultured together in the presence of mouse feeder cells.]

The text of the press release by ACT:

Alameda, CA, August 23, 2006 – Advanced Cell Technology, Inc. (OTC Bulletin Board: ACTC.OB) today reported that company scientists have successfully generated human embryonic stem cells (hES cells) using an approach that does not harm embryos. The technique is reported in an article appearing online (ahead of print) in the journal Nature. The article describes a method for deriving stem cells from human blastomeres with a single-cell biopsy technique called Preimplantation Genetic Diagnosis (PGD). This technique is used in in vitro fertilization (IVF) clinics to assess the genetic health of preimplantation embryos. The cell lines produced using this technique appear to be identical to hES cell lines derived from later stage embryos using techniques that destroy the embryo’s developmental potential. ACT had previously reported the successful use of a similar technique in mice in Nature in October 2005.

“Until now, embryonic stem cell research has been synonymous with the destruction of human embryos,” stated Robert Lanza, M.D., Vice President of Research & Scientific Development at ACT, and the study’s senior author. “We have demonstrated, for the first time, that human embryonic stem cells can be generated without interfering with the embryo’s potential for life. Overnight culture of a single cell obtained through biopsy allows both PGD and the development of stem-cell lines without affecting the subsequent chances of having a child. To date, over 1,500 healthy children have been born following the use of PGD.”

Current technology derives hES cells from the inner cell mass of later-stage embryos known as blastocysts, destroying their potential for further development. ACT’s approach generates human embryonic stem cells from a single cell obtained from an 8-cell-stage embryo.

To create hES cell lines, the researchers used single cells obtained from unused embryos produced by IVF for clinical purposes. Nineteen stem-cell outgrowths and two stable hES cell lines were obtained. These cell lines were genetically normal and retained their potential to form all of the cells in the human body, including nerve, liver, blood, vascular, and retinal cells that could potentially be used to treat a range of human diseases.

“One of the major ethical objections of those who oppose the generation of human embryonic stems cells is that all techniques, until now, have resulted in the destruction of the embryo,” stated Ronald Green, Ph.D., Director of Dartmouth College’s Ethics Institute and Chairman of ACT’s Ethics Advisory Board. “This technique overcomes this hurdle and has the potential to play a critical role in the advancement of regenerative medicine. It also appears to be a way out of the current political impasse in this country and elsewhere.”

“Our policy will be to work together with the scientific community to make new lines widely available for research,” stated William M. Caldwell IV, CEO of ACT. “Our ability to create human embryonic cell lines and therapies without harming the embryo should assuage the ethical concerns of many Americans. We look forward to potentially working with partners to produce significant medical benefit through the use of this technique.”

“While the continual advancement of science may, from time to time, appear to influence the political debate over human embryonic stem cell research, there are a host of good reasons to continue to allow and fund responsible and well-regulated embryo research, which may speed therapies to the bedside and improve reproductive medicine,” said Michael D. West, Ph.D., President and Chief Scientific Officer of ACT.

Other ACT scientists who contributed to this paper include Drs. Irina Klimanskaya and Young Chung (co-equal first authors), Sandy Becker, and Dr. Shi-Jiang Lu.

[IPBiz post 1938]


Blogger Lawrence B. Ebert said...

Note that ACT's Lanza is taking more flack about the stem cell experiments.

Reuters carried a story on September 6, 2006 which began:

Senators trying to promote human stem cell research rebuked a team of corporate scientists on Wednesday, saying their claims to have produced human embryonic stem cells without harming the embryo had misrepresented their work and hurt the cause.


They [ACT] said their research, published in the prestigious science journal Nature, provided an ethical way to produce the controversial cells.

But Sen. Arlen Specter, a Pennsylvania Republican who supports embryonic stem cell research, scolded the researchers, saying they had done no such thing.

Specter said the study's claims to provide an ethical alternative to destroying embryos "dramatic albeit false."

I posted the following to californiastemcellreport:

Note that in the discussion of the ACT flap (note above california stemcellreport post titled: Senators Scold Visibily Shaken Lanza), we can find some answers to "what other cells." For example, Reuters reported: And no cell lines were created from single cells, but instead created by incubating several cells together. Further, the groups of embryo-derived cells were cultured with mouse feeder cells. These are not "accusations" but rather facts that were omitted in the press releases by both Nature and ACT. More information is available here.

10:07 AM  
Blogger Lawrence B. Ebert said...

Rick Weiss, whose early article contributed to the ACT downslide, has another article entitled:

Senators Denounce Scientist's Stem Cell Claims

which concludes with the text:

Not addressed by the senators was a plainly incorrect announcement sent to science reporters by the journal Nature itself.

"By plucking single cells from human embryos, Robert Lanza and his colleagues have been able to generate new lines of cultured human embryonic stem (ES) cells while leaving the embryos intact," the release said.

That erroneous description -- written not by scientists at Nature but by the journal's lay staff -- was corrected after news stories were published.

Nature later apologized to reporters, blaming the mistake on "internal communication problems."

Lanza and the senators agreed on one thing: The quickest way to boost the availability of stem cells for research would be to pass legislation like that recently vetoed by President Bush, which would allow scientists with federal funding to study embryos about to be discarded by fertility clinics.

10:18 AM  

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