1. Announcements
Monday, April 23: genomic equivalence, cloning, and stem cells: pp
Wednesday, April 25: cell biology of cancer, pp ,
Friday, April 27, 9 AM: optional review session
Monday, April 30, 8 AM: final exam
139 points; 90 points from days 34-43; 49 points cumulative (days 1-43).

2. Outline/Learning objectives
Cloning
Embryonic Stem cells
After reading the text, attending lecture, and reviewing lecture notes, you should be able to:
Describe the potential fates of stem cells in general.
Distinguish reproductive cloning from therapeutic cloning.
Describe how embryonic stem cells are obtained, how they are assayed for potency, and how they can be used.

3. Cloning Mammals: Evidence of nuclear equivalence and reprogramming
Black (ooplasm donor)
Agouti (nucleus donor)
Cloned mice (Agouti)
Albino (nucleus donor)
^ Cloned mice (b. 1998) and their “parents.” Coat color is used as a marker. Conclusion:
Some differentiated nuclei can be completely reprogrammed.
Dolly (July 5, Feb. 14, 2003)
and one of her 6 lambs
Wilmut et al Nature 385:

4. Two ways to make an embryo: 1. Sexual reproduction
Source: Human Cloning and Genetic Modification: The Basic Science You Need to Know, Association of Reproductive Health Professionals, www. arhp.org

5. Two ways to make an embryo: 2. Cloning or asexual reproduction
“Nuclear Transplantation”
Source: www. arhp.org

6. Human Reproductive vs. Therapeutic Cloning
Reproductive cloning
Goal is to produce a clonal embryo to implant in a mother’s womb with intent to carry the child to birth.
Therapeutic cloning
Goal is to produce a clonal embryo to generate embryonic stem cells.
ES cells can be used to treat clonal donor without risk of immune rejection.

7. Top 10 causes of U.S. deaths (1998)
Heart disease
Cancer
Stroke
Chronic lung disease
Accidents
Pneumonia/influenza
Diabetes
Suicide
Kidney disease
Chronic liver disease
Tissue damage, e.g. spinal cord injury, also potentially treatable with stem cells.

8. Study Suggests New Avenue on Diabetes
By THE ASSOCIATED PRESS
Published: April 11, 2007CHICAGO, April 10 (AP) —
Thirteen young diabetics in Brazil have been able to stop receiving insulin after being treated with stem cells taken from their own blood, researchers are reporting.

9. What’s a stem cell? Stem cells are defined by their ability to:
Continue to grow and divide
Given the right signals (e.g. hormones or growth/differentiation factors), to differentiate into a specialized cell type
Stem cells have different potencies:
Unipotent: makes one cell type
Multipotent: makes several cell types
Pluripotent: makes most cell types
Totipotent: makes all possible cell types (zygote)

10. Where do stem cells come from?

11. Evidence for ES cell pluripotency

12. Evidence of adult stem cell pluripotency

13. But: the pleuropotency of adult stem cells may be exaggerated
Many such studies have not been replicated.
In contrast, the totipotency of embryonic stem cells is a fact.
However, the previously-approved lines have dwindled and newer, better lines are not allowed.
The Senate approved another stem cell bill President Bush has vowed to veto it again.

14. Stem Cell Therapeutics
Figures\Chapter21\DevBio7e21232.jpg

15. Some Stances on Human Cloning and Stem Cell Research
Support any human cloning
Few biomedical scientists
Clonaid (Raelians - Bahamas), Severino Antinori (Italy), Panos Zavos (Kentucky)
Oppose reproductive cloning, support therapeutic cloning
Many biomedical scientists
Hatch-Feinstein-Specter-Kennedy et al. bill S.303 in U.S. Senate
Nancy Reagan
Oppose any human cloning
Right-to-life groups: destruction of embryo, slippery slope
Brownback-Landrieu et al. bill S.245 in U.S. Senate
President Bush

16. ES cells in the news: The most spectacular fraud in biomedical research
What three accomplishments did Dr. Hwang Woo Suk claim?
First line of human embryonic stem cells generated from nucleus of adult cell > first step in therapeutic cloning (2004). FRAUD
Improvement in efficiency of above, generating ES cell lines from 9 patients > practical treatment through therapeutic cloning (Science : ). FRAUD
First cloning of a dog (Nature :641). VALIDATED
What ethical breaches apparently occurred in his laboratory?
Junior researchers were compelled to donate eggs for research in his lab.
Payments were made to egg donors through a Seoul hospital.
He lied about it this knowledge to the journal Science.
Dr. Woo Suk ordered subordinates to falsify data.

17. Korean Stem Cell Scandal, 2005-2006 (Hwang et al. 2005)
Duplicated
Duplicated
Cropped
Cropped
Cropped

18. Cancer cells defined by
Ability to proliferate uncontrollably
Causes tumor formation
Angiogenesis feeds the tumor
Cancer cells increase secretion of angiogenesis activators and decrease angiogenesis inhibitors
Ability to spread through the body.
Invasion: cancer cells migrate into surrounding tissues, blood vessels
Metastasis: cancer cells spread through circulatory system to establish secondary tumors.

19. Normal versus tumor growth in skin
Cancer cells don’t necessarily divide faster than normal cells.
Normal: Rates of cell division and differentiation balanced.
Tumor: Balance of cell division and cell differentiation favors cell division.

20. Normal and transformed cell properties
Transformed (cancer) cells
Uncontrolled growth
Independent of GF’s
Don’t obey checkpoints
Anchorage-independent
Loss of contact inhibition > pile up in culture
Escape apoptosis pathways
Rounded cells, large nuclei, abnormal chromosome number
Normal cells
Regulated growth
Dependent on GF’s
Subject to cycle cycle control
Anchorage-dependent
Contact inhibited (density-dependent)
Subject to apoptosis
Flattened cells, normal nuclei, normal chromosome number