Photo by Todd Mcnaught
The next great cancer therapy may be no further than your own back yard. That's the premise of a research collaboration spearheaded by cancer researchers at Fred Hutchinson and plant biologists at New Mexico State University (NMSU).
In conjunction with Dr. Julian Simon's laboratory in the Clinical Research and Human Biology divisions, a group of NMSU students are digging for potential anti-cancer therapies in the desert flora of the Southwest. The partnership aims to determine whether extracts from the native plants contain chemicals that could halt the growth of cancerous cells.
"The project initiated because we have a common interest in developing new cancer therapies, but we come at it from different fields of expertise," said Simon, whose laboratory last month hosted a visit from six NMSU students and their faculty adviser, Dr. Mary O'Connell. "Mary is a plant ethnobiologist with an interest in medical uses of plants. I don't know anything about plants except that I can't seem to keep an orchid alive."
What Simon does know a lot about is drug discovery. His laboratory has developed methods for rapid screening of chemical compounds for anti-cancer activity in both mammalian cells and yeast cells with defects analogous to those found in human cancers.
The project, one of six joint research ventures between the two institutions, is funded by a $2.5 million planning grant awarded last June by the National Cancer Institute's Comprehensive Minority Biomedical Branch. The NCI program aims to address disparities in cancer incidence and mortality in underserved ethnic minorities.
Boosting research capacity
The goal of the Fred Hutchinson/NMSU collaboration is to link a research-rich cancer center with an institution with a large minority-student population. Such partnerships aim to build cancer-research capacity at minority-serving schools and boost the pool of aspiring researchers and doctors who go on to train and work at cancer centers.
O'Connell, a professor of agronomy and horticulture, already sees signs of success.
"NMSU is an agricultural college, and since we don't have a medical school on campus, we don't have the opportunity to do much medically relevant research," she said.
"We have the knowledge of plant biology and Fred Hutchinson scientists have expertise in cancer-drug discovery. The opportunity for us to collaborate is very exciting."
The research partnership includes visits to Seattle by the NMSU students as well as exchange of research materials by mail. One NMSU graduate student will spend next fall semester working in Simon's laboratory and taking courses at the University of Washington.
"We could accomplish all this all via FedEx," Simon said. "But the goal is to provide opportunities for the students to come here to see how the experiments are done. Eventually, NMSU may be able to set up the plant-extract screening facilities at their own institution."
Mining nature's bounty for medicinal drugs is not new. The approach has yielded such well-known, plant-derived cancer therapies as taxol from the bark of the Yew tree and vinblastine from periwinkle.
O'Connell said that many drug-discovery efforts have focused on tropical plants, but there has been scant analysis of flora native to the American Southwest.
"There are a few references in the literature and some anecdotal evidence of anti-cancer activity of Southwestern plants," she said. "We're focusing on plants that would be expected to have similar properties to plants from other parts of the world suspected to have anti-cancer properties."
One example is the acacia plant, which has a close relative in Australia reported to contain compounds with tumor-fighting properties.
To test plant extracts for anti-cancer activity, Simon's lab relies on methods they originally developed for screening a chemical bank at the National Cancer Institute, which consists of more than 900,000 compounds donated by chemists who have synthesized or isolated novel chemicals.
Therapies years away
Extracts are first tested on strains of yeast missing the normal safeguards required for intact transit through cell division. Loss of such "checkpoints" is a hallmark of many human cancers. Plant compounds that are toxic to the mutant yeast-but harmless to normal yeast cells-will then be tested in human cancer cells that are propagated in the laboratory.
Simon said that several of the New Mexico plant extracts show activity in preliminary analyses and will undergo further testing.
New therapies generated from the project may be years away, but O'Connell said that the benefits of the collaboration are already apparent.
"Our students are very excited about the opportunity to take part in this study," she said. "We're not a medical school, so our ability to conduct cancer research is limited. This partnership affords us that possibility."
After all, she said, "successful cancer research requires the participation of all kinds of people."