An ironweed plant that grows wild on Hawaii island may offer new ways to combat deadly brain and breast cancers, and a University of Hawaii Cancer Center biologist has received $3 million in federal funds to study it further.
“It is very exciting,” James Turkson, director of natural products and experimental therapeutics in the Cancer Biology Program, said in an interview last week. “Chemical ingredients from the ironweed extract are effective in suppressing the functions of certain cancer-causing biological molecules. In response, the cancer cells stop growing and they die.”
His program is examining the cancer-fighting properties of a wide range of biological sources in Hawaii, including plants, marine organisms, fungi and soil bacteria. Ironweed, or Vernonia cinerea, which has small, delicate flowers, is among the most promising.
The National Cancer Institute made the five-year research award to Turkson last month after he and his colleagues demonstrated that ironweed extract could block the growth of brain and breast cancers in the laboratory. He has been working with UH Daniel K. Inouye School of Pharmacy associate professors Leng Chee Chang and Dianqing Sun, and professor Supakit Wongwiwatthananukit.
“It’s been a terrific collaboration within the university,” Turkson said. “It’s been very academically rewarding because we’ve learned a lot about the cancer-causing mechanisms that we would not otherwise have known.”
The researchers are hoping to use the natural ingredients to develop new drugs to treat glioblastoma, a brain cancer that has no cure, and aggressive forms of breast cancer that have few treatment options. Many medicines used to treat cancer today had their origins in naturally occurring compounds in plants and bacteria.
“It would be life-changing for cancer patients if ironweed extract could help fight aggressive types of breast and brain cancers,” Turkson said. “Since the compounds are found in the plant, they are less toxic than traditional forms of treatment such as chemotherapy.”
“Chemotherapy works very well on the cancer cells but also attacks certain normal cells, and that is why they end up being very toxic,” he added. “So the expectation is that these new molecular-targeted therapeutics that are coming, focused on hitting and interfering with cancer-causing biological molecules, are going to be a lot safer.”
The ironweed species found in Hawaii also grows in Southeast Asia. Clinical trials in Thailand, which packaged the plant in tea bags, found it helped people quit smoking without serious side effects, Turkson said. It has also been used in traditional medicine in that region to treat microbial infections as well as inflammatory and auto-immune diseases.
Along with ironweed, other natural products in Hawaii that Cancer Center researchers are focusing on include poha berry as well as sea sponges collected off the coast of Kauai. In lab experiments, chemical ingredients from the sponges worked well on brain tumors and breast cancers, while poha was effective in fighting breast cancer, Turkson said.
“The vast natural resources of Hawaii give our researchers a rare opportunity to make scientific discoveries of unique and significant proportions in treating cancer,” said Dr. Randall Holcombe, cancer center director. “This significant NCI award recognizes the breadth and depth of the natural product research focus of the UH Cancer Center, and highlights the national impact our research in Hawaii has in the fight against cancer.”
The researchers are studying the biological mechanisms that direct normal cells to become cancerous. They are focusing on the critical ones that drive cancer development and looking for ways to use natural products to interfere with that process.
“The biological molecule that is driving the cancer has gone haywire in its function,” Turkson said. “When the natural product interacts with it, it turns this haywire function off. That causes the cancer cell to recognize that it doesn’t have the life support any more that it depends on. And the cancer cells will stop growing and then they will die.”
The research team has tested ironweed grown on the Big Island as well as the Thai version and found they yielded similar results in the lab.
The researchers also plan to test ironweed on mice to gauge any potential for toxicity and develop data on appropriate dosing and frequency. In hopes of conserving the plant in the wild, they will work with chemists to develop synthetic variations of it.
