I know that they are adult cells that are reprogrammed to act like embryonic stem cells, but how exactly does it work? What are the benefits of these types of stem cells as opposed to other types; embryonic, adult? What are the disadvantages? I know that there is concern of them turning cancerous.
One of the benefits is that you can use somatic cells from patients, carrying disease-specific mutations. Thereby, you can generate iPS cells and subsequently differentiate them for in vitro disease modeling / drug screening.
You have cells with a more or less comparable differentiation potential like embryonic stem cells but you don't face ethical concerns and you have the gentetic background of the somatic cells. This is interesting when you think about regenerative medicine. Disadvantages are in my opinion the use of strong oncogens (when you use the magic four as plasmids and not use proteins to induce). Differentiation of pluripotent stem cells in certain lineages is not always totally comparable to cells which were taken from the corresponding tssue but once again you have no/less ethic concerns
Another potential problem when deriving and using iPSCs is the concept of epigenetic memory. Although iPSCs by definition have similar differentiation potential to embryonic stem cells, they frequently carry methylation patterns or residual epigenetic/transcriptomic markers that resemble the tissue source from which they were derived. This may complicate some applications that you wish to pursue. See http://www.ncbi.nlm.nih.gov/pubmed/24749075 or http://www.ncbi.nlm.nih.gov/pubmed/20644535 or search PubMed for additional details.
the transfection of somatic cells with certain transcription factors known to be expressed in pluripotent cells can drive the reprogramming of such differentiated cells back to a non-differentiated state resembling embryonic cells. This allows various advantages in disease modeling as you can use somatic cells (skin or blood cells) to be reprogrammed to pluripotent cells carrying the patient genome and subsequently differentiate them into the tissue that is more relevant to you for the study of the disease. Also it allows the development of stem cell therapies by editing the defective genome and transplanting the corrected cells back in the patient (this would circumvent problems associated to rejection as iPSC are derived from the donor). Also iPSC can be used for the bioengineering of organs. In fact there have been attempts at using donor organs that are decellularized by washing with certain detergents in order to leave only the scaffold structure of that organ and subsequently culture differentiated iPSC obtained from the very same recepient on such scaffold to recellularize the organ. This would allow the transplant of the organ without any rejection issue. Disadvantages on the other hand is the potential to become cancerous as certain transcription factors used for reprogramming are oncogenes. However this can be minimized by using certain combination of transcription factors and by avoiding integration of such factors by transfecting cells with vectors that are expressed episomally.
ipsc is one of the path breaking Nobel winning discovery which has revolutionised regenerative medicine, using candidate genes any somatic cells can be converted into stem cells. Japanese govt has approved conditional clinical trial on humans for age related macular degeneration which is good sign that it can be applied for many diseases in future
on flip slide virus used can integrate with the host which can be minimised by protein induced ipsc
See the attached article, it explains iPSCs and compares them to ESCs, and endogenous SCs.
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