MARIE CSETE MD, PhD CHIEF SCIENTIFIC OFFICER mcsete@cirm.ca.gov

MARIE CSETE MD, PhDCHIEF SCIENTIFIC OFFICER

mcsete@cirm.ca.gov

CANCER SURVIVAL

Early Development

DRUG DEVELOPMENT

TOXICICOLOGY

TRANSPLANTATIONDEGENERATIVE DISEASES

TRAUMA:Spinal cordBurnsHead injury

AGING

TISSUEENGINEERING

ALL STEM CELLS

CAN EITHER

-SELF-RENEW

and/or

-GENERATE SEVERALKINDS OF CELL TYPES

SELF-RENEWAL

Stem Stem

StemStem Stem

Stem Stem

X

XX

StemX

BLOOD STEM CELLS ARE PLURIPOTENT

“-POTENCY”

• Multipotent: A few

• Pluripotent: A lot

• Totipotent: Every kind of cell including cells of the body (somatic) and cells of the germline (eggs, sperm)

TOTIPOTENT

• ONLY EMBRYONIC STEM CELLS ARE CONSIDERED TOTIPOTENT

• BUT REALLY THEY ARE NOT TOTIPOTENT BECAUSE OF THE ISSUES OF COMPLEX ORGANIZATION

• ONLY THE FERTILIZED EGG

IS REALLY TOTIPOTENT

WHERE DO YOU GET THEM?

ADULT STEM CELLS

-ANY STAGE OF EMBRYO

-ANY STAGE OF ADULTHOOD

EMBRYONIC STEM CELLS

-BLASTOCYST EMBRYOS

-SCNT: Somatic cell nuclear transfer

-PARTHENOTES

-iPS: Induced pluripotent cells

University of Wisconsin website

University of Wisconsin, 2001.

University of Wisconsin, 2001.

University of Wisconsin, 2001.

. University of Wisconsin, 2001.

Embryonic stem cells are derived from the inner cell mass of the blastocyst stage embryo

University of Wisconsin, 2001.

In the lab, trophoblast is removed and the embryonic stem cells singly selected from the inner cell mass

University of Wisconsin, 2001.

ES cell cultivation in the laboratory: easier with mouse than human cells

University of Wisconsin, 2001.

Using a variety of tools, in theory any cell type can be made

HUMAN EMBRYONIC STEM CELLS

.

• Where they come from• Potency• Proliferative senesence (source material

abundance)

EMBRYONIC VS. ADULT STEM CELLS

Important differences:

1997—DOLLY andTHE ERA OF CLONEDANIMALS

+

ADAPTED FROM WWW.NIH.GOV/NEWS/STEMCELL/FIG4B.GIF

Blastocyst

Inner Cell Mass(Pluripotent)

Egg Cell (Remove Nucleus)

(Fusion)

Somatic Cell Nuclear Transfer

(Extract Inner Cell Mass)

Cultured PluripotentEmbryonic Stem Cells

Somatic Cell Nuclear Transfer: IS NOT HUMAN CLONING

Somatic Cell nucleus (any cell in the body other than an egg or germ cell)

(Stimulate Cell Division Process)

ADAPTED FROM WWW.NIH.GOV/NEWS/STEMCELL/FIG3.GIF

Patient advocacy for SCNT

• No immunologic barrier with cells generated from recipient

• Screening drugs for many common diseases using clones from families with inherited diseases

• First glimpse into early development

• Does not require use of embryos

Use for parthenogenetic lines

• Genetic homozygosity

• Bank cells with specific MHC proteins

• Other uses? Engineer cells for HIV resistancemake HSC for marrow transplantation

• SCNT AND PARTHENOGENESIS REQUIRE AN EGG

• Human egg donation is not trivial

All 3 germ layersrepresented-ectoderm-mesoderm-endoderm

Functional diffcell types

How/why would this work?

• Huge interconnectedness of protein

networks

• Changes silencing status of whole genome: These factor awaken silenced genes all over the chromosomes

• Ultimate test of pluripotency: Make a whole organism

iPS lines used to make mice

Reported simultaneouslyby 3 groups-Jaenisch (MIT)-Hochedlinger (Harvard)*-Yamanaka (Japan)

*20% of the 121 offspring developed tumors

-viral vectors?-not from vectors?

Hard problems

• What are network requirements for totipotency?

• Still left with little control over differentiation– Transcription and environment– Functional integration into tissue

• ES vs. cancer: Many overlapping traits

• Scale-up/manufacture: unsolved

Making ES cells easier than controlling them: MUSCLE

?muscle fat

Positive and negative signals

redoxreduce oxidize

CONTROL 2.

GUTSKINCARDIACMUSCLESKELETALMUSCLEPANCREATICBETACELLSHEPATOCYTESNEURONSSCHWANNCELLSASTROCYTESSMOOTHMUSCLEBONEPLATELETSREDCELLSWHITECELLSKUPFFERCELLSTENDON

Complex development

• Recapitulate the uterine environment and signals– Engineering interface critical

• Recapitulate the developmental course

ESdefinitive endodermforegut endodermpancreatic endoderminsulin producing mature beta cells

(Dr. Melissa Carpenter, NOVOCELL)

Growth cues to imitiate complex organization of embryos

Critical issues for translation

OLIGODENDROCYTES ASTROCYTES

?Transplant progenitorsrisk of astrocyte scarTransplant mature oligodendrocytesthey don’t survive transplant

Tumors and stem cells• Common traits: Undifferentiated, pluripotency, highly

proliferative, self-renewing, migration, common markers• Teratomas • Permissive environments • Cancer stem cells are those likely to escape treatment• Ultimately understanding stem cells will lead to

enormous gains in cancer biology• Chemotx wipes out stem cells?

Inner core: Slowly dividing neuroepithealial cells—Roy et al, Nature Med 2006