WHAT ARE STEM CELLS
Cells that have the potential to grow into any type of cell in the body are called stem cells. Since stem cells can develop into any cell, they form the foundation of growth, repair, and development in human beings and other living organisms. Stem cells are critical for any research due to their ability to differentiate into any cell indefinitely.
Now let us focus on how the concept of stem cells originated
The stem cell concept dates back to the late 19th and early 20th centuries. The term stem cell was first used by German biologist Ernst Haeckel in 1860. At that time it was used to refer to all the cells through which life developed, but upon advances in embryology and cellular biology, the modern concept of stem cells was developed. In research, further division of stem cells arrived, which pointed towards different types of stem cells:
PLURIPOTENT STEM CELL: They have the ability to differentiate into any type of cell in the body. These are the stem cells in the egg, which can develop into an entire organism through indefinite differentiation. Pluripotent stem cells are widely used in regenerative medicine, early development understanding, and testing of drugs.
MULTIPOTENT STEM CELLS: These are the cells that are found in specific tissues of the adult body, having two different types: hematopoietic stem cells, which are found in bone marrow, and mesenchymal stem cells, which are found in connective tissue, help in producing bone, cartilage, and fat cells. Used in bone marrow transplants and regenerative therapies.
TOTIPOTENT STEM CELLS: These stem cells are the most versatile and powerful stem cells, able to give rise to all types of cells in the body. These stem cells are cornerstones in the early development of multicellular organisms. It is also harmful if their growth is not precisely controlled, as totipotent cells may form tumors. Totipotent cells become different from pluripotent cells as totipotent stem cells can form extraembryonic tissues, but pluripotent stem cells cannot. For example, totipotent stem cells can form a placenta for a baby in the womb, but pluripotent stem cells cannot.
UNIPOTENT STEM CELLS: Unipotent stem cells are special cells that have the potential to self-renew, which helps in tissue maintenance and repair. They can differentiate to only one type of cell but have regenerative properties and thus help in the regeneration or repair of tissues. For example, muscle tissues, skin tissues, and sperm cells.
CANCER STEM CELLS: There are ways in which a normal cell can convert to a cancer stem cell. Such as mutation in normal cells, mutation in multipotent cells and fully differentiated cells can return to the state of stem cells, creating a potential cancer cell. In simple terms, these are the cells within a tumor that are responsible for the initiation of cancer, its progression, and its recurrence. Cancer stem cells can regenerate and can create various types of cells within a tumor. Cancer cells are also sometimes resistant to radiation and chemotherapy, due to which they can survive longer and cause cancer relapse.
As we study stem cells, we come across a number of stem cells, including cancer stem cells. Stem cell study shows that stem cells not only cause cancer but are used for treatment also. They can cure cancer through recovery after regressive treatment, or they directly target destroying cancer cells. There are numerous therapies to cure cancer, like chemotherapy and radiation surgery, but they have some side effects as well. But in the case of stem cells, there are many studies coming forward with the revolutionizing cures.
Let us see how stem cells help in cancer treatment:
BONE MARROW TRANSPLANT: This is also known as hematopoietic and is one of the most established cancer cell treatments, mainly used for treating blood-related cancers such as leukaemia, lymphoma, and myeloma. First, high-dose chemotherapy is used, and then healthy hematopoietic cells are transplanted to regenerate the body’s blood cell production. It can use the patient’s own cells or cells from a donor.
MESENCHYMAL STEM CELL: These cells are found in bone marrow, fat, and other tissues. They have the ability to carry themselves to tumor sites, making them a powerful tool for cancer-killing agents. They can be transferred via drug delivery by carrying anticancer drugs directly to tumor locations; they are also capable of delivering cytokines, which help in increasing one’s immune system to fight against cancer. They are also capable of carrying a virus called Oncolytic, which selectively destroys cancer cells.
INDUCED PLURIPOTENT STEM CELLS: Induced Pluripotent stem cells have the ability to be customized for specific uses. These can be defined as those somatic cells that are reprogrammed to pluripotent cells that can develop into any cell type. They can be used as training agents for the body by engineering them to express tumor-specific antigens that help in training the immune system to identify and attack cancer cells.
These are some of the methods used for cancer treatment through stem cells. They can either be used for a cure or for damage repair after any treatment. For example, tissue repair or bone marrow recovery that helps in blood cell production. As research is going on, these may soon become common practice for cancer treatments.
