Unit 4 Assessment Research

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A little acid can make a cell stemlike: mouse cells enter primordial state capable of making any tissue Author: Tina Hesman Saey Date: Feb. 22, 2014 From: Science News(Vol. 185, Issue 4) Publisher: Science News/Society for Science and the Public Document Type: Article Length: 732 words

Full Text: Creating stem cells may be as simple as dunking cells into a mild acid bath.

Doing so turned cells from newborn mice into ultraflexible stem cells that could grow into any type of body tissue, researchers report in the Jan. 30 Nature. Other stresses, such as squeezing cells through glass tubes, can also reprogram cells, Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe, Japan, and Brigham and Women's Hospital in Boston and colleagues discovered.

If it works on human cells, the technique could provide replacement cells for diseased body parts, foster a better understanding of a person's disease risks and drug sensitivities and maybe serve as a fertility treatment.

The method has floored other researchers, who thought that creating stem cells required more complex operations: extracting cells from embryos, transferring the nucleus of an adult cell to an egg cell or using viruses or other means to introduce factors that coax an adult cell to behave like an embryonic stem cell.

"It's fascinating. It's perplexing. It's potentially profound, but leaves lots of reasons to scratch my head," says George Daley, a stem cell researcher at Boston Children's Hospital and Harvard Medical School. "It's begging to be replicated," he says, adding that his lab will attempt to do just that.

In the new study, about 7 to 9 percent of cells from newborn mice survived the acid treatment and took just a week to form primordial cells, dubbed STAP cells for stimulus-triggered acquisition of pluripotency. Pluripotent

cells can develop into cells of any tissue. Both embryonic stem cells and reprogrammed cells known as induced pluripotent stem cells, or iPS cells, are pluripotent.

STAP cells may be even more flexible, Obokata says. When injected into mouse embryos, STAP cells not only incorporated into any body tissue but could also form parts of the placenta. That's a feat other pluripotent cells generally can't accomplish, and it may indicate that STAP cells are totipotent, or capable of forming a complete organism.

Obokata and her colleagues transformed skin, brain, muscle, fat, bone marrow, lung, liver and white blood cells from 1-week-old mice into STAP cells. The technique worked, but not as well, on cells from young adult mice that were 6 weeks old, she says. The researchers have begun testing the acid treatment on human cells.

Dieter Egli, a stem cell researcher at the New York Stem Cell Foundation, is skeptical. "If I were to describe this over a coffee break to one of my colleagues, they'd say, 'You must be kidding,'" he says. He knows of no mechanism that could explain how mild acid or squeezing changes a cell's fate so dramatically and consistently in one direction. Egli wonders why, for instance, blood cells became stem cells instead of transforming into muscle or any other type of cell.

Cells undergo stress in daily life, Egli points out. If simple acid or mechanical stress causes cells to revert to an early developmental state, he says, "it's hard to imagine how our bodies would maintain integrity over a lifetime."

But Qi-Long Ying, a stem cell biologist at the University of Southern California in Los Angeles, speculates that the body produces inhibitory factors that prevent stress from reprogramming cells. Without those inhibitions, lab-grown cells can regress to an immature state. Understanding how stress reverts mouse cells to the anything-goes state may teach researchers more about cancer, another condition in which cells have no particular identity.

Ethical barriers may pop up on the road to using STAP cells. Because STAP cells may be totipotent, UCLA stem cell researcher

James Byrne worries that the new technology may raise old specters of human cloning. Acid-reprogrammed cells potentially could grow into a fetus, placenta and all. If that's true, the cells might treat infertility by creating an embryo from an adult's cells, Byrne says.

Still unclear is whether researchers will choose STAP cells over other types of stem cells, says Louise Laurent, a stem cell biologist at the University of California, San Diego. Regardless, she says, the work "will inspire people to explore less traditional ways of changing a cell's fate."

Caption: By injecting a new type of stem cell into a mouse embryo, researchers showed that the cells could give rise to any type of cell in the body. Fetal tissues derived from the stem cells glow green.

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Please note: Illustration(s) are not available due to copyright restrictions.

Copyright: COPYRIGHT 2014 Science News/Society for Science and the Public http://www.sciencenews.org Source Citation (MLA 8th Edition) Saey, Tina Hesman. "A little acid can make a cell stemlike: mouse cells enter primordial state capable of making any tissue." Science

News, vol. 185, no. 4, 22 Feb. 2014, p. 6. Gale Academic OneFile, link.gale.com/apps/doc/A359334166/AONE?u=lirn50909&sid=AONE&xid=232bc040. Accessed 6 Feb. 2021.

Gale Document Number: GALE|A359334166