I. Interview with Professor Janet Rossant
One of the most important planks of medical research rests on a single mouse that was created in 1992. At the time, scientists believed that stem cells, a type of cell that can transform into other cells, could carry out only limited functions and turn into certain types of cells.
Professor Janet Rossant, a developmental biologist, thought otherwise. Working with other scientists, she created an entire mouse out of stem cells, showing that the cells can divide indefinitely and become every type of cell, whether blood, muscle, heart or lung.
Since then, scientists around the world have raced to explore the cells’ use in medicine and medical research. Prof Rossant, who is now a senior scientist at The Hospital for Sick Children (also known as Sick Kids) in Toronto, Canada, after a decade as its chief of research, also continued to break new ground.
She discovered a new stem cell type, called the trophoblast, that forms the placenta. She also led a team at Sick Kids that was the first to produce mature lung cells, from stem cells, that can be used to study cystic fibrosis, a genetic disorder, and test drugs against it.
In her CSC lecture, “Embryos, Stem Cells and Ethical Concerns”, she gave an overview of her research and the stem cell field at large.
Q: Your work at Sick Kids involves taking skin cells from cystic fibrosis patients and turning them into mature lung cells for medical research. How is this done, and how can it help the patients?
Prof Rossant: After we take the skin cells, we reprogram them into induced pluripotent (IPS) stem cells, which are essentially adult cells that have been genetically induced to function like embryonic stem cells. We can then turn these IPS cells into mature lung cells.
This process is important because, by using skin cells from patients, we can create mature lung cells that are specific to each patient. We can then test drugs against these lung cells to see which drugs would work for each patient.
Drugs for cystic fibrosis are extraordinarily expensive, and patients can have the same mutation and yet respond differently to the same drug. With our work, we can help to make sure that each patient gets the right drug at the right time. We are also creating a bank of IPS cells from cystic fibrosis patients to further our work.
Q: Can you tell us more about your research on trophoblasts?
Prof Rossant: I discovered trophoblast stem cells in mice. These cells surround an embryo and attach it to the uterine wall, eventually becoming the placenta. By studying these cells, we can understand more about placenta defects, which contribute to many pregnancy complications and problems. We are also trying to create human trophoblast stem cells.
Q: You’ve said that interdisciplinary collaboration will become increasingly important in stem cell research, and in science in general. Can you elaborate on this?
Prof Rossant: We can grow stem cells in petri dishes now, but if we want to treat patients with them, we have to find ways to produce millions of the cells. We need bioengineers and materials experts for that. That’s just one example of the interdisciplinary collaboration that will be needed to bring stem cells into regenerative medicine.
Science in general is becoming increasingly interdisciplinary too. Conferences such as the Commonwealth Science Conference are great because they allow scientists, especially young scientists, to come together and establish new relationships. This kind of meeting of minds across nations, cultures and scientific fields is really the way of the future.