Stem Cells and Cloning: Ethical Dilemmas in Medicine and Science

What are stem cells?

Stem Cells

• Type of cell from which all other cells in our body arise from

• Two defining characteristics:– Can divide and continuously renew themselves

both in vivo and in vitro– Ability to develop into specialized cells such as

muscle, nerve, skin, or pancreatic cells• Potential to cure many illnesses!

Stem Cells

• Totipotent (spores, zygotes)– Can produce all differentiated cells in an organism

including extra-embryonic tissue• Pluripotent (inner mast cells)– Can differentiate into any of the three germ layers

(endoderm, mesoderm, ectoderm)• Multipotent (adult stem cells)– Can differentiate into a single family of cells

• Oligopotent, Unipotent

Why have stem cells been so controversial over the past several

years?

Stem Cell Controversy

• Ethical debate concerning the creation treatment, and destruction of human embryos

• Harvesting pluripotent stem cells from human embryos kills them

• When does life begin? Does the embryo have rights?

But now we have new ways to acquire stem cells!

iPS Cells

• Induced Pluripotent Stem Cells• Adult cells can be reversed engineered to behave like

pluripotent stem cells• In 2006, a Japanese team lead by Shinya Yamanaka

was able to reprogram adult skin stem cells to behave almost like embryonic stem cells (won the Nobel Prize in 2012 for the importance of this work to regenerative science.

• In 2013, a Spanish team repeated this in vivo and they reverted to an even early state of development

Does this mean the debate is over?

No.

• Unlike hES cells, iPS cells can be derived from the somatic tissues of a wide variety of living donors.

• A living donor means many more ethical issues arise. – The re-contacting and tracking of donors– What to do with incidental findings that may impact a

living donor’s health– Extent and scope of donors’ reach-through rights to the

downstream research uses and commercial benefits of their genetically matched iPS cell lines

• Not a new issue.

Henrietta Lacks and HeLa Cells

• After 5th child, diagnosed with cervical cancer • During radiation, samples of cancerous and

healthy cells were removed without permission• Died from cancer in October of the same year

(1951)• Autopsy revealed her cancer had metastasized

throughout her body

Henrietta Lacks and HeLa Cells

• The cells that had been harvested were given to Dr. George Otto Gey

• He discovered that they continued to grow• Prior to this, scientists spent more time trying

to keep cells alive than studying them• Named immortal cell line HeLa• Sold around the world to scientists

Henrietta Lacks and HeLa Cells

• Used by Jonas Salk to develop the polio vaccine

• HeLa cells were the first to be cloned in 1955• Put into mass production• Mailed across the world for cancer, AIDS,

radiation, gene mapping, and other research• Family knew nothing about this.

Henrietta Lacks and HeLa Cells

• Family began receiving calls in the 1970s by scientists who wanted blood samples from them to determine their genetics

• Huge ethical debate—racism, commercial rights• Morehouse School of Medicine donated

headstones so that Henrietta and her daughter would not be buried in unmarked graves

Even with controversies, stem cell research has important

applications that can’t be ignored.

Are iPS cells really the same as ESCs?

• Heavily debated• ESCs are still the gold standard for which all others are

compared• By deriving and studying stem cells that are genetically

matched to diseases such as Parkinson disease and juvenile diabetes, researchers hope to map out the developmental course of complex medical conditions to understand how, when, and why diseased specialized cells fail to function properly in patients.

• One more viable way to produce disease-specific stem cells.

Somatic Cell Nuclear Transfer (SCNT)

• Research cloning• May be able to produce human ESCs that are

genetically matched to the patient and his or her particular disease

• SCNT has worked recently in non-human primates to produce cell donor–matched primate stem cells

• Human SCNT for disease research is, in principle, possible

Somatic Cell Nuclear Transfer (SCNT)

• Cloning is largely controversial• Limited funding available• Unpredictable with minimal success

Dolly

• The first successfully cloned mammal

Cloned Animals

• Dolly– 277 eggs, 29 embryos, 3 lambs, 1 Dolly

• Frogs– First cloned animals were frogs– Not 1 adult has ever been made

• Dozens of other types of animals have been cloned or attempted to be cloned.

What about cloning humans?

Ethical, Legal, Social Issues

• Should anyone have the right to have children no matter how they are created?

• Is human cloning, playing with nature?• Does therapeutic cloning justify destroying an

embryo?• Who is the parent of the clone?• What would the social challenges be of the

cloned child be as he/she grows up?• How should cloning research be regulated?

Why would we clone humans?

• Source of stem cells• Growing new organs• Replacing deceased children• Immortality?

Raelians

As of August 2008, they had over 70,000 members in 97 countries.

Raelian Beliefs• Raëlians seek to both genetically clone

individuals and rapidly accelerate growth of the clone to adulthood through a process like guided self-assembly of rapid expanded cells or even nanotechnology and then transfer the mind and personality of the donor into the clone.

• Raelians believe humanity can attain eternal life through the science of cloning.

• [Video]

Clonaid

• Human cloning company founded in 1997• Mark Hunt, West Virginia politician– Wanted to clone his deceased son– Donated $500000 for research equipment

• In 2002, Boisselier announced the production of a successful live-borne clone, named Eve, for an infertile couple.

• Refused to provide proof

Speaking With Congress

• Boisselier invited to speak with congress in March 2001

• Rael (Claude Vorilhon) brought with her.• Claude Vorilhon told lawmakers that banning

the development of human cloning was comparable to outlawing medical advances such "antibiotics, blood transfusions, and vaccines."

What do you think?