Iowa State scientist hopes to boost a flower's production of chemotherapy drugs

AMES, Iowa -- Jackie Shanks' work to make periwinkle plants better producers of chemotherapy drugs started with her sister's diagnosis.

Shanks was a graduate student at the California Institute of Technology in Pasadena in the late 1980s when she heard her sister Jenny of Des Moines had non-Hodgkins lymphoma. Shanks reacted by heading to the library, looking up the treatments and deciding to do more research work with plants.

Periwinkle leaves, after all, produce the indole alkaloids vincristine and vinblastine, used as the chemotherapy drugs Oncovin and Velbe. Besides, Shanks grew up outside Granger, Iowa, with a mother, Anna Vanni, who worked a three-acre garden and passed on her love of plants.

So when the AIChE Journal - a publication of the American Institute of Chemical Engineers - printed a picture of a rose-red flower on its January 2005 cover, it's no surprise Shanks had something to do with it.

Shanks, a professor of chemical engineering, advocates in that journal article for chemical engineers to use their expertise to advance plant sciences. She also coined a term, "phytocatalysis," to describe the reactions caused by plant enzymes that result in useful products and the work engineers do to study and improve those reactions.

An example is Shanks' work with root cultures of periwinkle plants (that's Catharanthus roseus, also known as Madagascar periwinkle or vinca). Shanks and collaborators Ka-Yiu San, a professor of chemical engineering and bioengineering at Rice University in Houston, and Sue Gibson, an associate professor of plant biology at the University of Minnesota in the Twin Cities, are studying a complex reaction pathway of more than 30 steps that leads to periwinkle plants producing small amounts of chemotherapy drugs. They'd like to manipulate the pathway so the plants will create more of the drugs. One benefit would be lower drug costs.

With the help of $588,848 in active collaborative grants from the National Science Foundation, they've made advances by changing the levels of different reactions along that pathway. But they haven't made it all the way to the reactions that create the chemotherapy drugs.

That's going to take more grants, more work, more molecular biology tools, more collaboration with plant scientists and more time. Shanks said bigger yields of chemotherapy drugs from periwinkle plants could be 10 years away.

Even though this particular research project has great challenges and a distant payoff, Shanks likes the idea of chemical engineers and plant scientists working together to solve problems.

"Given the exquisite chemistries in plants, and the numerous commercial applications," Shanks wrote in the AIChE Journal, "it is natural for chemical engineers to be involved in exploiting these chemistries."

Shanks' sister doesn't understand all the science, but she's glad her diagnosis might lead to a better way to produce some chemotherapy drugs.

"Life teaches you lessons," said Jenny Johnson, who's cancer free, the mother of two children, a first grade teacher at Jefferson Elementary School in Des Moines and a math consultant for the Iowa Department of Education. "One of the things I've learned from cancer is that some of the best things come out of the worst things."