D. Blicq dblicq@rrc.mb.ca    Nov. 2006    (update 03/17/2010) DIRECTORY I BIO I NOTICE BOARD

The use of stem cells in medical therapeutics is not new: bone marrow transplants have been employed to treat leukemia for nearly fifty years.  Over that same period, however, there have been numerous advancements in understanding the properties and functional characteristics of stem cells, as well as significantly improved methods of manipulation and replication. While it would be impossible to review the quantity of relevant research which has brought medical science to it's current level of understanding, a few select highlights are summarized below.

In 1999, Ernest McCulloch and James Till were made Fellows of the Royal Society of London and in 2004 both were inducted in to the Canadian Medical Hall of Fame for their ground-breaking work on stem cells. Both scientists have won numerous accolades and received world-wide recognition of the importance of their work.

Their work on stem cells began in the early 1960s when they observed that bone marrow cells injected into mice where able to survive and grow. By 1963 they had established that the "stem cells" were self-replicating - a fact that is included in the current definition of stem cells. It was the concept of cells that were potentially immortal that began to generate exceptional interest among researchers.

By 1968 the first successful medical treatment involving a bone marrow transplant between twins to treat Sickle Cell Disorder. A decade later in 1978 embryonic stem cells were discovered in placental and umbilical cord  blood, providing not only a second source of stem cells but a second type as well. Stem cells were first grown in vitro in 1992.  In 1997 it was demonstrated that leukemia can develop from a "cancer stem cell", indicating that unchecked cellular growth and differentiation can occur as a natural malignancy. In 1998  the first human embryonic stem cell line was officially reported by Thomson et al.

Currently there are numerous groups world-wide examining the fundamental nature of stem cells as well as applications for medicine and therapeutics.

A chronological review of related research and scientific highlights is listed in the timeline below:

Overview of Stem Cell Research

1959 - In-vitro fertilization successful (non human). This represents the first artificial fertilization successful outside of the organism. This establishes that the fundamental start of life can be conducted outside of a living organism.

1963 - Mucculloch and Til discover self-replicating stem cells (as described above). The potential of cellular immortality is extraordinary.

1968 - in-vitro fertilization successful (human). This establishes the potential for the artificial fertilization of human beings and is met with both enthusiasm and disdain.

1978 - in vitro fertilized human baby born, stem cells discovered in placental and umbilical cord tissues. The first "test tube baby" is a medical success but sparks significant debate regarding the role of medical science in the creation of life.

1981- stem cells (from blastocysts) isolated from mouse grown successfully in vitro. This means it is now possible to isolate and grow stem cells in tissue culture in the laboratory - creating a potential reservoir of stem cells for research and  / or therapeutic purposes.

1988 - pluripotent stem cells isolated and allowed to differentiate into various cell types. Researchers are now capable of inducing pluripotent stem cells to differentiate into selected tissue types as required (within certain limitations).

1992 - Human inner cell mass and blastocysts grown in tissue culture / in vitro. Researchers now have the capability of growing completely totipotent (unrestricted differentiation and replication capabilities) human embryonic stem cells in the laboratory.

1998 - Thomson et al successfully grow and propagate stem cell lines in vitro. Researchers are successfully growing and maintaining human embryonic and somatic cells lines using tissue culture techniques. This provides access to large numbers of stem cells for research and therapeutic purposes.

Currently - many groups are actively pursuing the propagation and identification of useful stem (and related) cell lines. Other researchers are actively seeking applications of stem cell technologies for a broad range of therapeutics.

 

 

Example areas of current stem cell research as listed by the US National Institute of health (NIH) includes:

1. Mouse Embryonic Stem Cells Help Save Mice with Liver Failure Nature Biotechnology 24:1412–1419 
2. Self-Replicating Insulin-Producing Cells Generated from Human Embryonic Stem Cells (hESCs) Nature Biotechnology advanced online publication
3. With Risk of Cancer, Human Embryonic Stem Cells (hESCs) Can Improve Motor Function in Rat Model of Parkinson's Disease Nature Medicine 12:1259–1268 
4. SCNT Works Better in More Mature Differentiated Cells than Adult Stem Cells Nature Genetics 38:1323–1328
5. Scientists Can Stop Skin Stem Cells from Maturing into Adult Skin Cells Cell 127:171–183
6. Further Evidence that Human Embryonic Stem Cells May Help Treat Vision Loss
   Cloning and Stem Cells 8:189–199
7. Protein Responsible for Balancing Stem Cell Growth, Aging, and Cancer
   aging. Nature 443:448–452  Nature 443:421–426  Nature 443:453–457 
8. Scientists Generate Human Embryonic Stem Cell Lines from Single Cells (Nature advance online publication, laboratory of R. Lanza)
9. Scientists Reprogram Adult Mouse Skin Cells by Adding Defined Factors
   Cell 126:1–14
10. Signaling Molecules May Help Adult Brain Repair Itself Following a StrokeNature advance online publication
11. Neurons Grown from Embryonic Stem Cells Restore Function in Paralyzed Rats
    Annals of Neurology 60(1)32–44
12. Nanog Reprograms Mouse Brain Stem Cells
    Nature 441(7096):997–1001
13. SCNT Works Better if Donor Nucleus is Less Mature
    Stem Cells 24:2007–2013
14. Scientists Identify Molecular Mechanisms for "Stemness"
    Cell 125(2):315–26 Cell 125(2):301–13
15. Pluripotent Stem Cells Found in Adult Mouse Testicles Nature advance online publication
16. Family of Proteins Keeps Human Embryonic Stem Cells Alive in Culture Nature Biotechnology advance online publication
17. Scientists Expand Mouse Blood-forming Stem Cells in the Laboratory Nature Medicine 12:240–245
18. Are Stem Cells Produced by Somatic Cell Nuclear Transfer Normal? Proceedings of the National Academy of Sciences of the USA 103:933–938
19. Mouse Stem Cell Study May Help Improve Human Breast Cancer Treatments Nature 439:84–88
20. Wisconsin Scientists Grow Human Embryonic Stem Cells without Animal Products
    Nature Biotechnology advance online publication

(source: NIH 2006)

Clearly the level and focus of stem cell research and development has grown significantly and now includes many previously "unrelated" areas.