Stem Cell Functions & Therapy

Stem cell functions
Stem cells exist in our bodies for the entire life-span and are found in almost all tissues. This indicates that these cells are of crucial importance in multicellular organisms where they perform diverse functions:

• During development they represent the first cells produced; they give rise to organ primordia.
  
• After tissues mature, the stem cells are responsible for maintenance of tissue structure as key regulators of tissue homeostasis.
  
• In case of injury, the stem cells are responsible for tissue regeneration
  

Stem cell therapy
Stem cells are endowed with unique properties that make them attractive candidates for the treatment of diseases that are currently intractable. These include degenerative diseases such as Parkinson Disease, demyelinating disorders (e.g. multiple sclerosis), Duchenne muscular dystrophy and many others. It also includes major diseases such as myocardial infarction, diabetes mellitus, autoimmune diseases etc. In experimental settings it has been demonstrated that the therapeutic potential of a single stem cell is so significant that it can reconstitute an entire organ, for instance the mammary gland, prostate or haematopoietic tissue in animal models. In the treatment of patients, a much greater number of stem cells is needed to shorten the time of therapy.

In stem cell therapy, there exist several therapeutic strategies:
- Stem cells can be transplanted to replace non-functional or lost stem cells in tissues, to accelerate tissue repair and restore the original function.
- In gene therapy, stem cells may be used as vectors to introduce missing genes into the target tissue.
- In anticancer therapy, stem cells that show affinity to tumours may be used as vectors to carry antitumour drugs and to replace the tumour cells.
- Knowledge on stem cell regulatory pathways may be utilized in stimulation of endogenous stem cells to repair the tissues.

Stem cell therapy is very promising and has several advantages:
i) it is apparently not toxic,
ii) it may be administrated once without the need for repetition,
iii) the progeny of transplanted cells assume phenotypes in the target tissue, and
iv) the therapy may be applied without the precise knowledge of mechanisms that control cell homing, their proliferation and differentiation.

Because of their broad differentiation potential and large proliferative capacity stem cell therapy might revolutionize medicine in the near future.