Carpenter transforms stem cells, self

Published: February 15, 2007  |  Source:

Melissa Carpenter of Novocell transforms stem cells and herself.

Life is transformed in the stem cell laboratories of Melissa Carpenter.

“These cells are the coolest cells there are,” says Carpenter, vice president of research for Novocell Inc. of San Diego and Irvine.

If you give an embryonic stem cell in a lab the right set of biochemical signals, it turns into a brain cell.

“It functions. It makes neurotransmitters,” she says.

If you signal it to turn into a heart cell, the cell beats.

If the biochemical signals tell it to turn into a pancreatic cell, it makes insulin.

“They’re absolutely amazing,” says Carpenter, her eyes sparkling.

But this column isn’t just about stem cells, the primordial cells that retain the potential to turn into almost any type of cell in the human body.

It’s also about Carpenter’s career in stem cell research, which has been full of transformations too. Carpenter’s life, as well as her lab, has often involved crossing borders that seemed like barriers, and figuring out the rules that apply on the other side.

Her personal transformations have included:

* Young girl into experienced scientist.
* Psychology major into stem cell expert.
* Academic researcher into corporate manager, and back, and then back again.

In the process, she learned to ignore “you can’t do that” advice. She also learned, to her surprise, that when she crossed the border from school into corporate America, teamwork was the rule, which hadn’t been the case in academia.


In high school and college, she was told not to pursue a scientific career.

“In high school, I was good at math and science, but I was encouraged to take home ec,” she says.

At the University of Oregon in the early 1980s, she became interested in psychology, and then in how the brain functions, but her advisers urged her not to pursue a Ph.D. in neurobiology.

“Women don’t do that,” they told her. “It’s going to be too hard for a woman.”

She persisted, earning her Ph.D. in neurobiology at UC Irvine in 1989, before studying brain cells in a postdoctoral fellowship at Colorado State University.

When she crossed into the private sector, she was again on her own.

“There are very few mentors for women in science,” she says. “When I got my first job, no one advised me about how to negotiate. My first salary was $17,000 a year after 10 years of college – it’s really sad.”


But she was lucky, she says, because she got in on the ground floor. Biotech company CytoTherapeutics Inc. in Rhode Island hired her as an associate scientist in 1995, a time when it was just starting to work with neural stem cells.

That took her across another “you can’t do that” barrier. At the time, the prevalent belief was that the cells of the brain had to be “hard-wired” because, if not, memory and regular breathing would be impossible, Carpenter says. When she heard about Swedish researchers transplanting embryonic fetal material into the brain of a patient with Parkinson’s disease, “I thought it was a stupid idea.”

But at CytoTherapeutics she studied neural stem cells from mice and from human embryonic tissue – with the goal of transplanting stem cells into patients with brain disorders.

“Here I am doing this thing that I thought was so stupid,” she says.

That research is currently bearing fruit, with clinical trials under way for neural stem cell transplants to treat Batten disease, a genetic defect causing shortages of a key enzyme in the brain.


From CytoTherapeutics, she moved to Geron Corp. in Menlo Park in 1998 – again with lucky timing. It was just a few weeks before a group led by biologist James Thomson at the University of Wisconsin announced that they had discovered how to grow embryonic stem cells from five-day-old human embryos.

That breakthrough opened the way to embryonic stem cells’ great potential for curing diseases, but it intensified the ethical debate over another border that researchers had crossed – taking stem cells from human embryos.

As senior scientist and then as director of stem cell biology at Geron, Carpenter explored stem cells’ potential for treating spinal cord injuries, heart disease, liver disease and Parkinson’s disease.

She left Geron in 2003, she says, when it “switched from research to product development.” She returned to academia, taking a stem cell research position and an associate professor’s post at the University of Western Ontario.


“People said I couldn’t do it. I had gone to the ‘dark side’ ” by working in private industry, Carpenter says. “Going back to academia was very strange … total culture shock.”

The pace was slower, and teamwork mattered less.

In private enterprise, she concluded, people must cooperate to help their company beat its competitors. After employees buy into their company’s goals, “they are very team-oriented, leave their egos at home, and work together,” she says.

“If you build a team right, you can go very, very fast and be very successful.”

In contrast, she says, the academic Environment often sets people in competition against each other.

“People don’t want to share. If they don’t get grants, they don’t get published. If they don’t get published, they don’t get tenure.”

Novocell hired her in 2004 as director of stem cell research and promoted her last year to vice president for research and development.

Her team has coaxed stem cells through a maze of biochemical pathways to the point where they’ve turned into embryonic pancreatic cells.

The company’s goal is to turn them into insulin-producing adult cells in time for clinical trials in 2010.

Carpenter’s work could help patients with diabetes, cancer, spinal cord injury, Parkinson’s disease and Batten disease, but it also satisfies her curiosity about the biochemical rules that govern stem cells.

“Being part of the therapy is an extraordinary opportunity,” she says. “But what gets you through the day is fascination.”

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