The Phoenix Online - Stem cell lab pushes conventional boundaries

BY ROSA KIM

Cloning. Stem cells. Regenerative medicine. These are terms you may have heard or read about in the news over the last decade.

For students in Stem Cells and Cloning taught by Visiting Professor of Biology Bill Anderson, these are topics they will be examining first hand — literally. They will perform experiments most undergraduates just read about. Some of the laboratory exercises include splitting flatworms to observe re-growth of entire body parts and instructing mouse embryonic stem (ES) cells to develop into specialized tissue.

This type of laboratory work is rarely done in undergraduate biology courses. In fact, according to Anderson and Biology Professor Scott Gilbert, Stem Cells and Cloning is the first course of its kind to be offered with a laboratory component involving hands on work with ES cells at the undergraduate level.

The moral, ethical and political implications of cloning and stem cell research have received a substantial amount of media attention, continuing to be subjects of heated debate. The actual science of stem cells and cloning, which is the focus of this new course, has not been a prominent topic in public discourse.

“It’s important to have students get an understanding of what is currently known in the field, separating the science from the hype, and have a true understanding of what the potential for this type of work is,” said Anderson.

Anderson is replacing Gilbert who is currently on-leave. He recently completed his doctorate in biochemistry from the department of molecular and cellular biology at Harvard University.

Anderson previously helped create a class on stem cells and cloning at Harvard in 2004, which was, to his knowledge, one of the first undergraduate courses on stem cell research. However, it did not include a laboratory component. Gilbert said that other institutions in the country have offered similar courses involving laboratory work with other types of stem cells such as from the bone, but none include ES cells.

“It excited me that there isn’t a textbook for this subject yet because the research is so new; all we read is primary literature. I just thought that was really intriguing,” said Macy Kozar ’10, a student in the course. Anderson is currently writing a textbook on stem cells and cloning for use in undergraduate and graduate courses.

“Plus, you hear about it all the time and I felt embarrassed as a biology person to not understand what people were talking about,” Kozar said.

“It’s a topic of great current scientific and ethical interest. And we feel like it’s important to educate ourselves and our students about the biology behind what’s going on,” said Biology Department Chair Sara Hiebert Burch.

Many within the scientific community have expressed their objection to reproductive cloning. Therapeutic cloning, however, which involves cloning cells, and not entire organisms, is another matter.

Scientists continue to look to stem cells in the hopes that they might one day be used to treat diseases such as Parkinson’s, Multiple Sclerosis, Alzheimer’s, Type 1 Diabetes and conditions such as spinal cord injuries. According to Anderson, ES cells are obtained from embryos at the blastocyst stage, roughly five and a half days after fertilization in humans and three and a half days after fertilization in mice. This is a critical time in which cells in the embryo are able to form into any type of tissue in the body. This creates the potential for growing cells genetically identical to a patient’s original cells that are affected by disease or injury.

Therapeutic cloning might also be able to aid in the development of models of a certain diseases in order to take steps toward preventing it. “By the time the patient is diagnosed, many of the cells that are affected are gone. You can’t really study what is happening in the initial stages of the disease, the middle stage and the

end stage,” said Anderson. He said that therapeutic cloning not only entails growing replacement cells, but it might be able to generate a cell-based model to help understand how certain diseases progress. “I think this will be a really powerful way to attack some of these diseases.”

ES cell research is, however, still in its infancy, and is also surrounded by many ethical controversies.

The potential to treat many people is a compelling reason for supporting human ES cell research, but it is also highly controversial because it involves the destruction of human embryos. This raises questions such as when human life begins. Scientific, theological and philosophical perspectives present many different viewpoints on this ancient question.

“I think the probability with [ES cell research] is that you’re inevitably going to make an industry out of creating human embryos through cloning in order to get the stem cells,” said Patrick Tiedemann ’08, a member of the Swarthmore Students Supporting Life group. “There’s definitely going to be a price on them because of the scientific research and the money that goes into that. I think it trivializes and puts in danger the value of life.”

“When you start to realize that embryos are going to have a cash value on them, there’s inevitably going to be women who will want to sell embryos for money.

That would have to be something that has to be watched out for. It’s an exploitation of the ability of women to

harbor these embryos,” he said. “I think that what’s

really cool is that there are adult stem cells which have yielded therapeutic results. In that sense, you’re

not cloning human embryos, something that can potentially become human. You’re just using stem cells that are naturally in humans, in umbilical cords and other parts of the adult body … You’re not artificially creating them.”

According to Anderson, adult stem (AS) cells, otherwise referred to as tissue-specific stem cells, are found throughout the adult body, such as the skin and in blood. While these cells do not have the ability to form all of the different cell types present in the body, they do play important roles in maintaining tissues in the adult. The course will evaluate, among other topics, the advantages and disadvantages of ES versus AS cells.

In the lab, students will work hands–on with mice ES cells that have been isolated from early stage mice embryos. They will see how the mice ES cells grow and differentiate on their own to observe how they generate special cell types. Later, they will allow the ES cells to differentiate into specialized tissue in the presence of certain signals.

Studying functions in simpler organisms might contribute to a better understanding of human biology. They will also work with planaria, a species of non-parasitic flatworms with a strong regenerating capacity. According to Anderson, students will conduct Thomas Hunt Morgan’s historical experiment splitting the planaria and observing the phenomenon in which they regenerate entire missing body parts. Anderson said they will delve into questions such as what types of signals are responsible for instructing the worm to do this and why planaria have this regenerating capacity that humans, except for the ability to regenerate parts of the liver, do not have.

Burch said, “In [the biology department], we never ask a student to do anything that they are uncomfortable with. And if they are taking a class and a part of it is uncomfortable for them, they are more than free to say, ‘this is not something that I feel I can participate in’ and we’re happy to provide an alternative activity or something else. As long as they learn the intellectual content then that’s considered fine.”

Given the ethical and political ramifications surrounding stem cell research, the course includes an ethics and public policy lecture later in the semester to open up the discussion about various ethical perspectives and to help students form their own informed opinions.

“So far, it’s been historical studies that have been done in the field. Thus far, I haven’t gotten the chance to delve into the issues that really question my ethical values. But I really hope that the class does because that is a really pertinent issue,” said Mark Mai ’09, a biology major in the course. I think eventually there is going to come a point when I’ll probably have to take a stance on whether or not all this stem cell controversy really bothers me.”

For Anderson, given that this is such a publicly contested issue, the main goal for the course is for students to be able to explain the science and then come to their own conclusions.

Reverend Joyce Tompkins, Swarthmore’s Protestant Religious Advisor said she supports the goals of the course. “Stem cell research and cloning offer great promise for future healing and should definitely be taught to Swarthmore students preparing for careers in the biological sciences,” she said in an e-mail.

“But students should always be taught to think deeply about the ethical implications of this work. Ethical or moral intelligence is just as important to a Swarthmore education as is factual knowledge. This is not an either/or proposition, nor an easy answer, but a balancing act, searching for the greatest good.”

http://phoenix.swarthmore.edu/2007-09-27/news/17456