• Necessity to know about human embryonic stem cells (ESCs)
  • Niloofar Torkzade,1,* Mozhgan Shirazi,2
    1. Department of Biochemistry, Islamic Azad University, Falavarjan, Iran
    2. Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran


  • Introduction: Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which time they consist of 50–150 cells. After many months of growth in culture dishes, these remarkable cells maintain the ability to form cells ranging from muscle to nerve to blood, potentially any cell type that makes up the body. In this study, we investigate the importance of embryonic stem cells and their valuable applications
  • Methods: We reviewed about 22 articles were conducted from 2017 to 2019 in the world and Iran. We searched some key words such as embryonic stem cells, blastocyst stage and transplantation therapy, DNA damage, drug discovery and genetic disorders in Sciencedirect, Elsevier, PubMed and SID.
  • Results: The proliferative and developmental potential of human ES cells promises an essentially unlimited supply of specific cell types for basic research and for transplantation therapies for diseases ranging from heart disease to Parkinson's disease to leukemia. Currently most research about ESCs focuses on differentiating ESCs into a variety of cell types for eventual use as cell replacement therapies (CRTs) or in other words, cell-based transplantation therapies. Besides becoming an important alternative to organ transplants, ESCs are also being used in field of toxicology and as cellular screens to uncover new chemical entities (NCEs) that can be developed as small molecule drugs. In this context, ESC-derived hepatocytes or cardiomyocytes are useful models that could be used in the preclinical stages of drug discovery. Several new studies have started to address the concept of modeling genetic disorders with embryonic stem cells. Either by genetically manipulating the cells, or more recently, by deriving diseased cell lines identified by prenatal genetic diagnosis (PGD), modeling genetic disorders is something that has been accomplished with stem cells. This approach may very well prove valuable at studying disorders such as Fragile-X syndrome, Cystic fibrosis, and other genetic maladies that have no reliable model system. Another use of embryonic stem cells is their use in repairing DNA damage. Stem cells persist for long periods in the body and experience many intrinsic and extrinsic stresses. For this reason, they present a powerful and effective DNA repair system in order to properly fix DNA damage and avoid the onset of a degenerative process, such as neoplastic transformation or aging.
  • Conclusion: Human embryonic stem cells (ESCs) have the potential to differentiate into various cell types, and, thus, may be useful as a source of cells for transplantation or tissue engineering. Aside from these uses, ESCs can also be used for research on early human development, certain genetic disease, and in vitro toxicology testing. Due to the valuable applications of stem cells, further studies need to be done to more aspects of their applications specified in biology and medicine.
  • Keywords: embryonic stem cells, transplantation therapies, DNA damage, drug discovery, genetic disorders