AMHERST, Mass. – Two sophomores at the University of Massachusetts Amherst are working on a new method to boost production of the world’s best-selling chemotherapy drug, Taxol, and perhaps save a multitude of the yew trees that produce Taxol in the bargain.
Amit Shavit and Nik Finneran work in the laboratory of Susan Roberts, a professor of chemical engineering who is conducting research that could dramatically increase the world’s production of Taxol, one of the closest things human beings have to a cure for cancer.
“What Taxol does is induce the death of cancer cells. Specifically, it binds to micro-tubules, which are important in cell division, and prevents the cancer cells from dividing properly,” says Roberts.
For the next three years, Shavit and Finneran, who graduated from high school in Lexington, Mass. before enrolling in the UMass Amherst chemical engineering department, will be working with incubated flasks of media solution containing thousands of yew-cell clumps called aggregates, developing a new technique designed to squeeze as much Taxol as possible out of the cells that metabolize this life-saving drug.
“We think that the cells in the middle of each aggregate will produce more Taxol because they have a different metabolism than cells on the outside, since the cells inside get fewer nutrients,” says Shavit. “Getting fewer nutrients might stunt the growth of cells, but it will also boost their metabolism so they will make more Taxol.”
The basis of their research is proving that cells in the middle of the aggregates will produce more Taxol, and then determining how to process aggregates that are the right size to metabolize the highest amount of Taxol.
“Because the cells in the middle of these aggregates don’t have access to nutrients, they enter into a state of no-growth,” adds Finneran. “But they’re not dead. To survive and keep functioning, they start producing more Taxol.”
Taxol, the patent name for this drug as sold by Bristol-Myers Squibb, was first extracted in the 1960s from the bark and leaves of the yew tree, Taxus brevifolia, known as the “Tree of Life” by the ancient Druids, who considered it their emblem for immortality.
Taxol has proven so effective since being licensed by the Food and Drug Administration in the 1980s that new methods of supply will be the key to meeting increasing demand. The Taxol explosion generates more than $2 billion in revenue each year, putting a huge strain on this limited resource, and hundreds of thousands of yews are debarked or cut down to meet the demand.
“Taxol is very expensive, and the supply of yew trees is limited,” notes Shavit. “You can’t keep cutting down trees to keep up with the rate of production of this drug.”
“We hope our research will help boost the more efficient production of Taxol,” adds Finneran.
In the yew tree, Taxol is produced as a defense mechanism against insects and other invaders. In medical circles, this same defense mechanism has been approved by the FDA to treat breast, ovarian and lung cancers, as well as an AIDS-related cancer known as Kaposi’s sarcoma.
Taxol is not only a wonder drug for cancer, but it is proving to be good medicine for Shavit and Finneran. Both arrived at UMass Amherst last year with little concept of what chemical engineering entails or what they wanted to do once they earn their degrees.
But their research on Taxol has helped structure their whole education. Both Shavit and Finneran are students in the honors program at UMass Amherst, known as Commonwealth College, and their Taxol research will form the basis for the capstone project of their undergraduate education, their senior honors theses. What’s more, after getting a taste of exciting research while studying Taxol, they are both applying for further research gigs through various summer Research Experiences for Undergraduates at several universities, including UMass Amherst, and also applying for student internships with various companies.