Stem Cells : Therapeutic Perspectives @ Pankaj Prasad Department of Molecular & Human Genetics BHU, Varanasi

“ The phenomenon of life itself negates the boundaries that customarily divide our disciplines and fields.” Hans Jonas (1966)

Stem Cells??

Definition “ A Stem cell is a clonal, self-renewing entity that is multipotent and thus can regenerate several differentiated cell types.”

Embryonic Stem Cells (ESCs)

Embryonic stem cells

James A. Thomson The Thomson Laboratory

Sources of embryonic stem cells In – vitro Fertilization (IVF) Nuclear transfer The largest potential source of blastocysts for the stem cell research is from IVF clinics. As all fertilized eggs are not implanted, it results in a large bank of “excess” blastocysts, stored in freezers around the globe.

Somatic Cell Nuclear Transfer (SCNT)

Adult stem cells

Sources of adult Stem Cells

Induced Pluripotent Stem (iPS) cells

Shinya Yamanaka, M.D., Ph.D. Professor, Institute for Frontier Medical Sciences

Next generation iPS cells

Kevin C. Eggan Harvard University Department of Stem Cell and Regenerative Biology Stowers Medical Institute

Epigenetic reprogramming Konard Hochedlinger had shown that it is possible to create mouse iPS cells using an adenovirus in place of the retroviruses previously used. Harvard University Department of Stem Cell and Regenerative Biology Massachusetts General Hospital

Transdifferentiation Refers to the conversion of one differentiated cell type to another and considered a subset of metaplasia. Faculty of Arts and Sciences, Harvard University Howard Hughes Medical Institute

Cancer Stem Cells (CSCs)

leave patients prone to recurrence. Cancer stem cells Current cancer therapies may fail because cancer stem cells have not been eradicated. leave patients prone to recurrence. Pulling out a weed while leaving the roots.

Origin of cancer stem cells

Treatment

Stem cell niches Scadden D.T. Nature 2006

Scadden D.T. Nature 2006

Slow cell cycling of stem cells Quiescence stem cells Quiescence Slow cell cycling of stem cells Unresponsive to many chemotherapeutics that typically target rapidly proliferative cells

Zebra fish : Model system for stem cell research Harvard Magazine

Role in basic research

NIH, U.S.

Stem cell research centers

Stem cell research in India

Stem cells Banks

Major BMT centers in India Bone Mar08 Bone Marrow Transplantation (2008

Law Moral values Ethics

Peer review

“Human reproductive cloning should not be practiced. It is dangerous and likely to fail.” Scientific and medical aspects of human reproductive cloning. National Academic Press, 2005.

Conclusion Stem cell research is being pursued in the hope of achieving major medical breakthroughs. Currently only a few diseases are treatable with stem cell therapies because scientists can regenerate only a few types of tissues. Future fundings will provide more insights into the mechanisms regulating the stem cell pluripotency.

References

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