Cancer stem cells first identified in leukemia

[Guest guest]

Science Daily, March 19, 2008

" Cancer stem cells were first identified in leukemia, but they have also been

found in breast, brain, colon and prostate cancers. They are also resistant to

virtually any kind of treatment, and some scientists believe they are the reason

cancer recurs. Until now, no one has known how they arise.

" But a team of scientists, led by Dr. Jian-Xin Gao, a researcher in the

department of pathology at Ohio State University Medical Center, has identified

a new set of cells he calls precancerous stem cells (pCSCs). These cells share

some of the characteristics full-fledged cancer stem cells have, but they are

different in that they respond to distinct cell signals that determine their

ultimate fate -- whether they will continue to grow into cancer or cancer stem

cells, lie inactive or be eradicated by the body's immune system.

" These hybrid cells are very complex. They have properties of normal and

abnormal stem cells, and do not always lead to cancer -- only some of the time,

and under very specific conditions, " says Gao, who is also a member of the Ohio

State University Comprehensive Cancer Center. " These cells appear to be a whole

new class of cells involved in the development of cancer. "

" Cancer stem cells were first identified in leukemia, but they have also been

found in breast, brain, colon and prostate cancers. Because they are rather

unstable, they are notoriously tricky to isolate and describe. They are also

resistant to virtually any kind of treatment, and some scientists believe they

are the reason cancer recurs. Until now, no one has known how they arise. A

team of scientists, led by Dr. Jian-Xin Gao, a researcher in the department of

pathology at Ohio State University Medical Center, has identified a new set of

cells he calls precancerous stem cells (pCSCs).

" These cells share some of the characteristics full-fledged cancer stem cells

have, but they are different in that they respond to distinct cell signals that

determine their ultimate fate -- whether they will continue to grow into cancer

or cancer stem cells, lie inactive or be eradicated by the body's immune system.

Wu and her team currently are testing therapies that target the alterations they

discovered, hoping to interrupt the process that causes the blood stem cells to

become leukemia stem cells, thereby preventing the cancer. They're also looking

for other alterations that might be at play in transforming the normal stem

cells into cancerous stem cells.

*****************************************

How Stem Cells Develop Into Blood Cells

ScienceDaily (Mar. 12, 2009) — How messages sent within stem cells through a

specific communication pathway can trigger the cells to specialize and become

blood cells in humans, has been discovered by scientists of the McMaster Stem

Cell and Cancer Research Institute.

" The finding, to be published in the March 6 issue of Cell Stem Cell, marks the

first time scientists have demonstrated the importance of the pathway, known as

the noncanonical Wnt, in inducing blood formation in humans or any other

species. The pathway works by organizing the cells so that they can respond to

signals for blood development. Mick Bhatia, is the lead investigator of the

study, which involved researchers from McMaster University,

Medical Institute and the Randall T. Moon Institute for Stem Cell and

Regenerative Medicine at the University of Washington.

" By directing cell differentiation, this method provides the most efficient way

to produce blood cells that we are aware of to date, " said Bhatia. The work

also provides a new way to make blood from human stem cells that could be used

for clinical applications to regenerate the immune and blood system in patients,

including those with leukemia or undergoing cancer therapies that indirectly

destroy the immune and blood system.

" Stem cells are the building blocks of every organ and tissue in the body.

Through the process of cellular differentiation, moving from a less specialized

cell to a more specialize cell, stem cells have the ability to become any type

of cell in the body including bone, muscle and blood cells. In addition to the

primary finding, the researchers also looked at second pathway and found that,

unlike the first, it did not trigger the formation of blood cells. However, the

second pathway did play a role in temporarily increasing the production of blood

cells. "

This project was funded by the Canadian Cancer Society with additional support

from the Canadian Institutes for Health Research and the Stem Cell Network.

///////////////////////// Adapted from materials provided by McMaster

University.

Parts quoted here are from the following website:

http://www.sciencedaily.com/releases/2009/03/090305121651.htm

*********************************

Science Daily (Sep. 12, 2008)

" Unlike embryonic stem cells, the use of adult stem cells in research and

therapy is not controversial because the production of adult stem cells does not

require the destruction of an embryo.

" Researchers expect to have initial testing completed to begin the first phase

of clinical trials within 5 years led by Postier, M.D. The compound, if

successful in human trials, is expected to be available to the public within 10

years. "

A quarter of the funding for the cancer research comes from an $800,000 grant

from the National Institutes of Health with remaining funds from the University

of Oklahoma College of Medicine. Materials provided by University of Oklahoma.

Entire article is available at this website:

http://www.sciencedaily.com/releases/2008/09/080911140813.htm

FYI,

Lottie Duthu