Imagine looking through a microscope and seeing dozens of tiny cells – that you had grown, been feeding and tending for a week – beating together. The dance of life.
When I was assisting with research into stem cells of the heart, I had that magical experience.
But being able to grow cells in a lab and make them beat is a far cry from being able to regenerate someone’s sick heart after a myocardial infarction, what scientists call a heart attack.
Stem cells may also play a major role in cancer.
What are stem cells?
Your body is made up of an amazing variety of tissues. You’ve got a brain, a liver, blood and an immune system. Stem cells are simply cells before they differentiate, take up a specific role and specialize.
The good news is that your body has the right stem cells to take care of day-to-day living. In your bones, for instance, millions of stem cells are constantly joining the immune system, becoming blood, or a variety of roles.
The bad news? Your body simply can’t heal certain types of damage, like in your brain or your heart. After a heart attack, the part of your heart that dies because it temporarily didn’t receive blood, will almost certainly never recover. The same is true for the damage to your brain caused by a stroke.
Research into stem cells aims to solve that problem. While your body on its own might not be able to regrow the right brain cells, it’s theoretically possible to make them in a lab then inject them in. Hopefully, once inside the body the prepared solution will replicate and recreate what was originally there.
What are embryonic stem cells?
At one point your body grew everything that’s inside of it. It created its own heart, its own brain. It was able to do so because it contained exceptionally powerful stem cells while it was an embryo, developing inside the womb, and those stem cells are logically called embryonic stem cells (ES).
The theory is to harvest ES from a fertilized egg just as it begins to grow and does not possess any characteristics that traditionally define humanity. Then, with those cells, we could theoretically create any kind of cell whatsoever, allowing for therapies that treat some of the worst diseases.
Ignoring the moral issues around ES, several major problems exist. First, is guiding the cells to form into the right tissues. Second, because ES posses such powerful growth capability, it is entirely possible that they could become cancerous. And finally, since ES are derived from someone else, your body’s immune system might react and try to kill them.
Stem cells and breast cancer
Over the past twenty years, deaths from breast cancer (BC) have fallen sharply, but 44,000 women still die annually from it. Treatments are hitting a plateau. Once the BC metastasizes, or spreads, fatality rates are still similar to what they used to be.
Stem cells might offer a way to attack the disease further, and better.
The old model of cancer development is that it’s random. Cells spontaneously turn cancerous and start growing. That this is possible and happens is indisputable. But it’s also possible that stem cells, because of their growth abilities, are specifically becoming cancerous (cancer stem cells, CSC).
The CSC model has very important implications. It explains why some BC is so resistant to radiation and chemotherapy. Additionally, it offers new targets for medications, like the stem cell specific Hedgehog, Notch and Wnt pathways. It also impacts how one would detect BC earlier on, and what ideas are good for prevention.
At the moment, evidence for CSC is based on limited experiments.