F00574 003 f010

Therapy

Approaches

Some problems

Gene therapy

Replacement of defective or therapeutic gene (e.g. growth factor)

Retrovirus-

therapy gene inserts into host celi genome -> effect

DNA virus-

expresses desired protein

Inject into target tissue (muscle, bonę marrow)

Host immune response negates therapy

Viral virulence

Viral recombination

Disruption of host gene(s) at insertion sites

Insertional mutagenesis Unregulated protein levels (too little or too much)

Stern cells

-Embryonal

Spare/IVF embryo cells

Cultured and expanded

Add specific growth factor cocktail

l

Develop early differentiated cells

I

Inject into

e.g. CNS. myocardium

Uncertain efficacy

Oncogenesis

Inappropriate celi types

Lack of functional integration into target organ

Ethical issues with embryonal tissue use

Stern cells

-Adult

Take adult autologous cells, e.g. bonę marrow

i

Separate stem cells by surface markers and e.g. FACS

1

Insufficient cells

Time to replicate sufficient cells in vitro

Some tissues have few stem cells

Oncogenesis

Lack of functional integration into target organ

Replicate in vitro

(± some diff

erentiation)

Inject into target organ

© Elsevier. Boon et al.: Davidson's Principles and Practice of Medicine 20e - www.studentconsult.com