1. 1.3. What are the differences between Stem Cells, PRCs and Adult Induced Pluripotent Stem CellsiPS cells claimed by Japanese and American researchers?
    • 2010/10/15 9:06:19
    Stem Cells:
    Functionally, stem cells are the multipotential, self-renewing cells that sit at the top of the lineage hierarchy and proliferate to make differentiated cell types of a given tissue in vivo. [2]  
    The two broad types of mammalian stem cells are: embryonic stem cells that are isolated from the inner cell mass of blastocysts, and adult stem cells that are found in adult tissues.
    Stem cells can also be classified according to the origins or functions as follows: those transformed from tissue cells are called tissue (somatic) stem cells.  Based on the functions, stem cells can be categorized into several types: totipotent, pluripotent or monopotent stem cells, like hemetaopoietic stem cells (HSC) with only the single function of hemopoiesis.---Human Body Regenerative Restoration Science (under the process of publishing).
    Stem cells in the monograph titled Human Body Regenerative Restoration Science by Dr. Rongxiang Xu refers to the dynamic cells with the potency of proliferation and differentiation to form normal tissues or organs (or functional cells). Those which can proliferate and differentiate but not form the normal tissues or organs (or functional cells) should not be classified as stem cells, like cancer cells; the same case is with the common cells with injury repair ability which also have the proliferation and differentiation function but form the scar tissues instead of normal tissues.
    In a word, any cell called as a normal stem cell should share the common character of proliferation and differentiation to form normal tissues or organs (or functional cells). It is a serious concept mistake to term cells without the ability to form normal tissues or organs (or functional cells) as stem cells. For example, none of the virus assisted gene reprogrammed induced Pluripotent Stem (iPS) cells[3] has developed into the normal stem cell, not even mentioning to form normal tissues or organs, thus the claim of iPS cells as induced stem cells was a severe concept mistake. Instead, the inventor should name the iPS cells according to the actual cell character, not by borrowing the existing term.---Human Body Regenerative Restoration Science  
    PRCs are special type of adult cells, also termed as specially differentiated tissue cell. Originating from different stages of development, they reside in tissues as ordinary matured adult cells but retain the potential of converting into stem cells and regenerating functional tissue organs. The technique of tissue organ regeneration in situ by the induction of PRCs into stem cells has been applied in clinics for various diseases such as full-thickness skin wounds, subcutaneous wounds, gastrointestinal mucosa inflammation & ulcers and so on. In all, PRCs are the mother of stem cells.
    iPS cells:
    Thirdly, iPS cells[3] are obtained by gene reprogramming technology, i.e. to implant four genetic genes into skin cells with a special viral vector, and manufacture skin cells with functions of embryonic stem cells after reprogramming of the genes. The reconstructed cells are called iPS cells. However, they are not truly stem cells, there is no evidence to verify that this type of cells have totally the same functions as that of embryonic stem cells; and the viral vector that was used by the technology to carry four genetic genes may result in cancerization, teratoma and even cytometaplasia. Therefore, there is still a long way to go before the clinical application of iPS' cells.