By Jonny Lupsha, Wondrium Staff Writer
Stem cell research regularly generates hot debates over its ethics. A new therapy that has repaired the spinal cords of more than a dozen patients is raising eyebrows for both good and bad reasons. Why is stem cell therapy so controversial?
Patients who have received treatment from their own stem cells to repair their spinal cords are at the center of controversy after the stem cell therapy was fast-tracked in Japan in 2018. Despite 13 patients showing considerable recovery in response to the treatment, the means to this end have suggested improper shortcuts taken in the last several years.
It isn’t the first time that stem cell research has been in the spotlight for ethical reasons. One controversial method of obtaining stem cells is to take them from human embryos, which has been argued about for decades. However, alternatives to embryo use are coming to pass.
A Most Delicate Subject
In his video series Biochemistry and Molecular Biology: How Life Works, Dr. Kevin Ahern, Professor of Biochemistry and Biophysics at Oregon State University, said much about stem cells and the science that surrounds them.
“There are two things that are special about stem cells,” Dr. Ahern said. “One is that they are capable of dividing indefinitely—that is, as long as the organism is alive. The other is that they are undifferentiated—they’re like a child who hasn’t yet chosen whether to be an astronaut, ballerina, surgeon, or an artist.”
Dr. Ahern said that when stem cells divide, they can either differentiate and become a specialized cell or they can go back into the stock of stem cells. In an embryo, at the earliest stages of development, the fertilized egg divides to produce a certain number of unspecialized cells called embryonic stem cells. They become specialized by receiving certain signals, so scientists can learn what these signals are and send them to unspecialized cells to make them develop as they wish. This could mean making them become cells to repair nerve damage, heart muscles, and more.
However, some see this as tampering with nature and/or stealing cells from the embryo. Regardless of our opinions one way or the other, these ethical concerns have been raised, prompting scientists to find alternatives.
Reverse Engineering
How else can stem cells be obtained, if not from embryos?
“One solution is the production of what are called induced pluripotent stem cells, or iPS cells,” Dr. Ahern said. “Pluripotent refers to the ability of a stem cell to give rise to other differentiated cell types. To do this and yet avoid working with cells from a human embryo, scientists begin with differentiated somatic cells [like] cells from the skin of an adult, for example.”
Once they’ve isolated the differentiated somatic cells, scientists reverse engineer them into a state in which they can become any number of differentiated cells or tissues. Dr. Ahern said that iPS cells have been used to create beating heart cells, motor neurons, light-sensing photoreceptor cells, insulin-producing pancreatic cells, and more.
“In 2017, Japanese researchers reported that monkeys with Parkinson’s showed great improvement after treatment with dopamine-producing neurons derived from iPS cells,” Dr. Ahern said. “In 2018, clinical trials with humans were begun using iPS cells to treat Parkinson’s, heart disease, and macular degeneration.”
For now, stem cell therapy remains no stranger to controversy—or results. The debate raging around them will likely continue in one way or another for some time.