Stem+Cell+1

Stem Cell Fact Sheet: • What are Stem Cells: o Common person definition: Cells in the human body that have the potential to develop into different ceil types (non-differentiated cells) o Types of Stem cells and where they are found: « Embryonic: Fetal tissue and blastocysts « Intermediate: Placenta, Umbilical Cord, Baby teeth • Adult: Adult organs and tissue ex. Bone Marrow • Terminology associated with Stem cells: o Blastocyst: the phase of development in which a fertilized egg has divided more than 32x producing 3 distinct layers, these layers are • Inner cell Mass: layer of cells that will become the fetus • Mesoderm and exoderm( outer cell mass): layers of cells that form the placenta o Pluripotent: The ability of a cell to become/ differentiate into any/all of the 220 different cell types( has no initial preference of become one cell type over another, they have no "memory") » Only Embryonic stem cells have been shown to be pluripotent o Telomeres: sequences of DMA, regulated by the enzyme teiomerase, that lengthens DNA to allow it to replicate » When a ceil loses its ability to replicate cell death ensues (results are aging of the organism) • What is a stem cell line: o "Self replenishing colonies of stem cells." o One stem cell produces many other stem cells creating a colony of non-differentiated ceils • Different Stem Cells How Cells are obtained for cell lines: o Embryonic • Fertility clinics-discarded eggs as a result of in-vitro fertilization process • Aborted fetuses • Cloning: note* cloned fetuses are known as "entities" • Made to order: Like fertility clinics but without the intension of using the embryos for reproductive purposes (make them just to make them) o Adult and Intermediate: // • // Donation What is federally funded and How does federal funding work for Stem cell research o 22 embryonic stem cell lines have been established pre-2001 using Fed. Funds. After Aug. 2001 no other stem cell lines were allowed to be established using Fed.-Funds o If an institute receives Federal Funding they cannot create new embryonic stem cell lines whether the funding is going directly to that or not. o Samples of the 22 original embryonic stem cell lines can be purchased from the University of Wisconsin using federal funds. This is the only allowed federal funded research involving embryonic stem cells, o Funding • Regulated funding from the National Institute of Health (NIH) • In Aug. 2001 -$250 million was allotted for stem cell research (maintaining the existing embryonic stem cell lines and researching Adult and Intermediate stem cell lines) • As of Aug. 2006-only $90 million was allotted for stem cell research with the same restriction as 2001 funding • -64% cut in funding • $160 million cut in 5 yrs = ~ $32 million cut each year o Problems with Federally funded embryonic stem cell lines • Limited genetic variations, Researches Need approximately 100 embryonic stem cell lines to see a large enough genetic.variation to do research. • The stem cell lines are older • Despite the ability for stem cells to continually divide, the more division occurs the more mutation also occurs and is passed on. • Adult stem cell line and intermediate stem cell lines tend to differentiate even before being exposed to different cell types do to inherited cell memory • There is no way of pinpointing how this cell memory occurs or even what triggers it but once a cell differentiates it will only produce one cell type; • These cells age. • What stem cells are used for o Gene therapy o Creation of new tissues and organs o Repair and regeneration of nervous system o Research for cancer treatment: Looks specifically at telomeres. Telomeres of cancer cells are more similar to embryonic stem cells than any other type of cell. •
 * || Embryonic || Intermediate || Adult ||
 * Pluripotent || yes || to a small extent || Not very much ; tend to have cell/ tissue memory ||
 * Where derived || Reproductive cells such as fertilized eggs || Somatic cells and reproductive intermediates || Somatic cells only ||
 * Other stuff || Unlimited regeneration; telomeres don't shorten ||  || Limited regeneration, telomeres shorten lifespan. dependent upon type of tissue memory. ||