2002 ASCB Annual Meeting Press Book - page 8

THE AMERICAN SOCIETY FOR CELL BIOLOGY
42ND ANNUAL MEETING
December 14-18, 2002, San Francisco, CA
Putting Stem Cells to the
Test
Toti-, pluri-, or multi-, stem cells are supposedly sort-
able by potency. The truth is, four years into the stem cell era,
we are still exploring stem cell potential and still finding sur-
prises. Here’s another. A team led by Suzanne Kirby and col-
leagues at the University of North Carolina at Chapel Hill and
the Duke University Medical School has demonstrated for the
first time cross-species hematopoietic transdifferentiation of
a cloned and easily genetically-altered liver stem cell line
from a male rat into functional bone marrow cells in female
mice.
The rat stem cells, naturally marked by the y-chromo-
some and artificially marked by transgenes, were injected into
female mice whose bone marrow had been damaged by radia-
tion. Six to eight weeks later, mouse bone marrow was har-
vested and analyzed for cells with the rat-specific markers.
Then individual colonies of blood-making cells from the trans-
planted mice were cultured for closer examination. Half the
colonies were examined genetically for two key types of multi-
potent blood stem cells, myeloid and lymphoid progenitors.
Compared to control results, rat-markers—the rat Y-
chromosome and an inserted transgene—turned up in 59 per-
cent of the colonies with myeloid cells and in 90 percent of
the colonies with pre-B (pre-lymphocyte) cells. Examined by
microscope, the stem cell-transplanted colonies had devel-
oped into a wide complement of blood cell types—including
neutrophils, monocytes, megakaryocytes, macrophages, eryth-
roid, and pre-B cells¾, although T cells have not yet been
found at these early time points.
The researchers’ cloned rat liver stem cell line, WB-
F344, had been used in earlier experiments where liver stem
cells were shown to transdifferentiate into cardiac myocytes.
By transplanting to another species, they hoped it would be
easier to track the stem cells and thus demonstrate a com-
plete “proof of concept” that stem cells derived from one tis-
sue line could be cloned and transplanted to a host where
they would transdifferentiate into new tissue without fusing
with the host’s cells. This, they have accomplished, says Kirby
and colleagues, adding with traditional scientific restraint,
“This transdifferentiation of adult stem cells could prove use-
ful for tissue repair.”
Contact: Suzanne L. Kirby, University of North Carolina at
Chapel Hill, Medicine, CB#7295, LCCC, Mason Farm Rd,
Chapel Hill, NC 27599-7295, (919) 966-1947,
Hematopoietic cell transdifferentiation of cloned adult liver-
derived stem cells.
Suzanne Kirby
1,2
, Stuart Bentley
2
, James
Fry
2
, William Walton
1
, Niyati Desai
2
, Ann Latour
3
, William
Coleman
2
, Page Anderson
4
, Joe Grisham
2
, and Nadia Malouf
2,
Departments of Medicine
1
, Pathology
2
, and Genetics
3
, Uni-
versity of North Carolina at Chapel Hill and Department of
Pediatrics, Duke University Medical Center
4
At the ASCB Meeting: Program 680. Poster B660, Stem
Cells. Author presents: Sunday, December 15, 1:30 —3:00
PM.
Morphology of G418 resistant, Y-chromosome + colonies. A) erythroid,
B) megakaryocyte, C) macrophages, D) immature myeloid and neutrophils.
STEM CELLS
6
1,2,3,4,5,6,7 9,10,11,12,13,14,15,16,17,18,...20
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