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Following embryonic development, most of our tissues and organs
are continuously regenerated from tissue/organ specific stem cells. The
principal property that distinguishes such stem cells from their daughter cells
is self-renewal; when stem cells divide they give rise to stem cells (by
self-renewal) and progenitors (by differentiation). In most tissues only the
primitive stem cells self-renew. Stem cell isolation and transplantation is
the basis for regenerative medicine. Self-renewal is dangerous, and therefore
strictly regulated. Poorly regulated self-renewal can lead to the genesis of
cancer stem cells, the only self-renewing cells in the cancerous tumor.
Known as a renowned medical researcher, an entrepreneur,
and an avid fisherman, Irving L. Weissman is Director of the Stanford Institute
for Stem Cell Biology and Regenerative Medicine, Director of the Stanford
Cancer Center and Director of the Stanford Ludwig Center for Stem Cell
Research. A Professor of Pathology and Developmental Biology and, by courtesy,
of Biological Sciences and Neurosurgery at Stanford University Medical School,
Weissman's research encompasses the biology and evolution of stem cells and
progenitor cells, mainly blood-forming and brain-forming. He is also engaged in
isolating and characterizing the rare cancer and leukemia stem cells as the
only dangerous cells in these malignancies, especially with human cancers. And
he has a long-term research interest in the phylogeny and developmental biology
of cells that make up the blood-forming and immune systems. Weissman's
laboratory was first to identify and isolate the blood-forming stem cell from
mice, and has purified each progenitor in the stages of development between the
stem cells and mature progeny (granulocytes, macrophages, etc.).
As a pioneer in the field of adult stem cell biology, Weissman co-founded three
stem cell companies: SyStemix in 1988, StemCells in 1996, and Celtrans (now
Cellerant), the successor to SyStemix in 2001. At SyStemix he co-discovered
the human hematopoietic stem cell and at StemCells, he co-discovered a human
central nervous system stem cell. In addition, the Weissman laboratory has
pioneered the study of the genes and proteins involved in cell adhesion events
required for lymphocyte homing to lymphoid organs in vivo, either as a normal
function or as events involved in malignant leukemic metastases.
Irving L. Weissman's research encompasses the phylogeny and developmental biology of the cells that make up the blood-forming and immune systems. His laboratory identified and isolated the blood-forming stem cell from mice, and has defined, by lineage analysis, the stages of development between the stem cells and mature progeny (granulocytes, macrophages, etc.). This required developing and cloning stromal cells of the hematolymphoid microenvironments—from the bone marrow for myeloid and B cells, and from the thymus for T cells. While the adhesion molecules and factors from these stromal cells proved important as molecules (and the genes that encode them) for myeloid and B cells, the analysis of T cell development required in vivo studies of thymic development. In addition, the Weissman laboratory has pioneered the study of the genes and proteins involved in cell adhesion events required for lymphocyte homing to lymphoid organs in vivo, either as a normal function or as events involved in malignant leukemic metastases.
The Weissman laboratory also has a small group at Hopkins Marine Station, where they have developed a model organism for laboratory and field study of allorecognition—the invertebrate counterpart of transplantation immunity. Working with the protochordate Botryllus schlosseri (which has a chordate larval stage and an invertebrate adult form) they have identified a single major gene locus that governs rapid allorecognition, and 2-3 other loci involved in delayed allorecognition events. They are using this model to study the genes, proteins, and cells that govern protochordate allorecognition, and the effects of these genes on their population dynamics in the field.
Normal and neoplastic stem cells [electronic resource] / Irving L. Weissman.
Series:
NIH director's Wednesday afternoon lecture series
Author:
Weissman, Irving L. National Institutes of Health (U.S.)
Publisher:
[Bethesda, Md. : National Institutes of Health, 2008]
Other Title(s):
NIH director's Wednesday afternoon lecture series
Abstract:
(CIT): Following embryonic development, most of our tissues and organs are continuously regenerated from tissue/organ specific stem cells. The principal property that distinguishes such stem cells from their daughter cells is self-renewal; when stem cells divide they give rise to stem cells (by self-renewal) and progenitors (by differentiation). In most tissues only the primitive stem cells self-renew. Stem cell isolation and transplantation is the basis for regenerative medicine. Self-renewal is dangerous, and therefore strictly regulated. Poorly regulated self-renewal can lead to the genesis of cancer stem cells, the only self-renewing cells in the cancerous tumor.
