Stem cells 101

Regenerative medicine depends on stem cell investigation to discover better ways of helping people. Currently, diseases and injuries are mainly treated with drugs, surgery and rehabilitation, which can alleviate symptoms but does not always provide a cure. Stem cell therapies, however, could potentially help people move away from reliance on expensive, long-term drug treatments, because stem cells confront the disease at its source and can stop the progression of a disease or even cure it.

For example, stem cell research has the potential of freeing those living with diabetes from daily blood-sugar checks, regular insulin shots, and all of the risks associated with the disease. This kind of therapy is beneficial for patients and also alleviates long-term costs on the health care system.  In the decades to come, we will see cell therapies and technologies introduced that will change the face of health care and improve the lives of millions.

Stem cell therapies are already being used to treat blood cancers such as leukemia (e.g. through bone marrow donation) and aggressive multiple sclerosis (MS). But they also hold extraordinary promise to one day treat many more diseases and conditions, such as type 1 diabetes, heart disease, kidney disease, other types of cancer (e.g. skin, breast, lung, testicular), spinal cord injuries, neurological disorders (e.g. Alzheimer’s and Parkinson’s diseases), arthritis, and eye diseases that can lead to blindness.

There are two main kinds of stem cells used in research today:

1. Pluripotent stem cells are essentially “blank slate” cells. They can give rise (also called differentiate) into any cell type in the body, making them extremely powerful tools for regenerative medicine. There are two kinds of pluripotent stem cells:
   1. Embryonic stem cells are derived from 4-5 day old blastocysts. They can differentiate into any of the three germ layers: endoderm (interior stomach lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone, blood, urogenital), or ectoderm (epidermal tissues and nervous system). Using embryonic stem cells in research has been controversial due to ethical concerns and as a result, strict guidelines for their use are in place in Canada and many other countries around the world.
   2. Induced pluripotent stem cells (iPS cells) are created using an adult stem cell (such as a skin stem cell) that it genetically reprogrammed back into a pluripotent state. This advance was made in 2007 by Dr. Shinya Yamanaka, who was awarded a Nobel Prize for this discovery. Today, iPS cells are widely used in research, as they avoid many of the ethical issues surrounding embryonic stem cells. They are not identical to embryonic stem cells, and their exact potential is yet to be fully understood.
2. Adult stem cells are the stem cells that exist in most of our organs and tissues. They are more limited in their potential than pluripotent stem cells, in that they can only form the types of cells of that organ in which they reside. For example, a hematopoietic stem cell can only form cells in the blood system, a muscle stem cell can only form muscle tissue, and so on. Despite this limitation, adult stem cells are extremely useful for study purposes, and are currently used in the clinical setting, most commonly to treat blood disorders through a hematopoietic stem cell transplant (using blood stem cells from the bone marrow).

Stem cells were discovered by James Till and Ernest McCulloch at the Ontario Cancer Institute in 1961 while investigating the effects of radiation on mouse bone marrow. They published this finding in the journal Radiation Research and have since become known as the “Fathers of Stem Cell Science”. It is thanks in part to Till and McCulloch’s collaborative spirit and dedicated mentoring of young scientists that Canada became a centre of stem cell innovation and a leader in regenerative medicine.

While stem cell therapies hold much promise, many are still being tested for safety and efficacy. This means that there are very few stem cell therapies offered in the clinic by medical professionals as the standard of care. Despite this, clinics worldwide advertise treatments to people in Canada who are seeking cures for disease or illness. Travelling to another country to undergo an experimental treatment (stem cell tourism) can be expensive, ineffective and even dangerous. However, when faced with life-threatening disease, many want the ‘right to try’ an experimental or unproven treatment.  The ethics of this are significant and it is an issue that members of SCN’s policy research community are working on. To read more about “right to try” arguments click here.

When considering a stem cell therapy it’s important to have the right information and ask questions before the procedure. A Closer Look at Stem Cells website was designed to be a comprehensive guide.

Not all unproven stem cell therapies are aimed at those with disease. Many clinics are offering anti-aging treatments, or other products meant to enhance physical appearance, activity or mobility. In many cases, celebrities and professional athletes are known to promote and market these types of treatments. Research shows that the public trusts celebrity spokespeople and can be taken in by persuasive marketing campaigns.

SCN Policy researchers, Timothy Caulfield (University of Alberta), Ubaka Ogbogu (University of Alberta) and Amy Zarzeczny (University of Regina) work with international counterparts to grasp the implications of stem cell tourism, to promote better regulation and accreditation, and to separate facts from false claims.

Learn more about stem cell tourism in this SCN video, narrated by Professor Timothy Caulfield.