• Question: What are stem cells?

    Asked by anon-256630 on 12 Jun 2020.
    • Photo: Alena Pance

      Alena Pance answered on 12 Jun 2020:

      Hi Claudia, stem cells are very special cells that have the potential to become a range of different types of cell. So embryonic stem cells are those that form after fecundation of the egg by the sperm that give origin to all the tissues of the body. Hematopoietic stem cells are those that can generate all the different cells of the blood, like red blood cells, lymphocytes, macrophages, megakaryocytes, etc. So there are stem cells in adults too but there aren’t many of them and to overcome this, a technology was developed a decade ago or so to turn differentiated cells like skin or blood, back into a stem cell status in vitro. This is called reprogramming and it has been so useful that the man who discovered how to do this, Yamanaka, and british John Gurdon, who crucially demonstrated in the 60s that every cell of the body has the same whole genome, won the nobel prize for medicine in 2012 for this development.

    • Photo: Emma Daniels

      Emma Daniels answered on 12 Jun 2020:

      Most cells are specialised and carry out a specific function in the body. Stem cells is a type of cell that has the ability to divide and develop into many different types of specialised cell. Because they can divide over and over again, they are used in the body to replace cells that have been damaged or lost.

      There are three types of stem cell: embryonic, adult, and induced pluripotent stem cells. Embryonic stem cells are found in embryos. These types of stem cells are pluripotent, meaning they can develop into any type of cells. Adult stem cells are found in the brain, skin, and bone marrow. These cells are multipotent, meaning they can change into a several types of cells, but not all types. For example, adult stem cells in the skin can develop into the different cells that make up skin and hair. Induced pluripotnent stem cells are made in the lab. A normal cell, such as a skin cell, is taken and ‘reprogrammed’ to become a stem cell. Once made, these cells are also pluripotent so can turn into any type of cell.

      Stem cells are very useful for research and in medicine. For example, the adult stem cells found in bone marrow can develop into all types of blood cell (including red blood cells, white blood cells, platelets etc). Therefore bone marrow transplants can be used to treat conditions that affect blood. The adult stem cells in the new bone marrow help to replace damage and lost blood cells in the patient. This is used to help treat conditions such as leukemia, a type of cancer that effects the blood.

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