Menstrual blood tapped as source of stem cells

[Guest guest]

Menstrual blood tapped as source of stem cells

Finding may offer happy medium between embryonic and other adult

cells

http://www.msnbc.msn.com/id/21996417/

While the excitement continues to swirl around the recent

breakthrough of converting skin cells to stem cells, other

researchers are quietly pursuing a new type of stem cell discovered

in menstrual blood.

These menstrual stem cells could offer several advantages. They come

from a source that's easy to obtain from women, they could be used

to treat patients without the fear of tissue rejection, and they

avoid the ethical questions associated with embryonic stem cells.

Researchers from Medistem, a biotechnology firm in Tempe, Ariz.,

reported the discovery of the new stem cells, dubbed endometrial

regenerative cells, in this month's Journal of Translational

Medicine. Plans are already under way to investigate whether they

can be medically useful.

Ichim, Medistem's chief of scientific development, said the

company is currently conducting animal studies to determine the

potential of the stem cells for treating several human disorders,

including diabetes, multiple sclerosis and cirrhosis of the liver.

Stem cells come from two main sources: embryos or adult tissues.

Embryonic stem cells can give rise to virtually any cell type in the

body, but they are controversial because conventional procedures for

obtaining them involve the destruction of an embryo. Adult stem

cells, such as those found in bone marrow, do not pose the same

ethical concerns, but they have limited powers and collecting them

can require invasive procedures.

While the new technique of reverting skin cells to an embryonic stem

cell-like state promises to overcome the ethical dilemmas, this

approach could come with safety concerns that make the cells too

risky for use in humans. The technique for converting the skin cells

involves using viruses to insert several genes, one of which is

known to cause cancer.

Menstrual stem cells could turn out to be a happy medium between

embryonic and adult stem cells, providing an ethically acceptable

alternative that is readily accessible and appears to give rise to

most of the major tissue types in the body, said Ichim.

" Compared with the stem cells from other sources, such as bone

marrow and cord blood, [menstrual stem cells] are easier to collect,

do not cause any harm or pain to the donor and can be collected for

more than 35 years, from 12 years old to 47, " said Xiaolong Meng of

the Bio-Communications Research Institute in Wichita, Kan., who

collaborated on the research that resulted in the discovery of the

new stem cells.

Meng and Ichim's team had a hunch that stem cells may aid in the

rapid expansion of the uterus lining during a woman's monthly

period. To investigate this, they collected a small amount of

menstrual blood from healthy women while they were menstruating. The

researchers hit pay dirt, isolating a new type of adult stem cell.

Experiments in lab dishes showed that under the right conditions,

the menstrual stem cells could turn into more different tissue

types — including bone, blood vessel, fat, brain, lung, liver,

pancreas and heart — than other adult stem cells. The new stem cells

also grow readily and rapidly, which is an important advantage

because it is difficult to get some types of adult stem cells to

give rise to enough cells to be of any medical value.

Other stem cell researchers were split on the research, with some

calling the results promising and others remaining skeptical.

Dr. Lanza, chief scientific officer at Advanced Cell

Technology, a company in Los Angeles developing medical treatments

based on stem cells, called the discovery " exciting, " saying the

menstrual stem cells appear to have several advantages over other

types of adult stem cells.

" For starters, they're easy to obtain, " Lanza said. " And since,

they're the patient's own cells, you don't need to worry about

immune rejection, a major problem associated with the use of

embryonic stem cells. "

The lack of immune rejection could extend beyond women from whom the

cells were initially derived. Ichim says the menstrual stem cells

seem to have an immune system-suppressing effect that could enable

them to be transplanted into other people without rejection.

Arnold Kriegstein, director of the University of California San

Francisco Institute for Regeneration Medicine, was unconvinced about

the potential of the menstrual stem cells to transform into all the

different tissue types claimed by Medistem. " Some of these claims

are overblown, " Kriegstein said, adding that a more thorough study

would be required to demonstrate the full capacity of the stem cells.

However, Ichim says Medistem has more data about the menstrual stem

cells than they have made publicly available. He said unpublished

experiments in animals and lab dishes indicated the cells give rise

to different tissue types and show promise for treating disease.

Still, the company will have to convince the FDA of the medical

potential of the cells before being allowed to proceed with clinical

trials in people. Ichim declined to set a timeframe for when studies

in humans might begin, saying that more animal research is required

before they can plan for using the cells in people.