One of the largest repositories in the United States of North American freshwater cyanobacteria, conventionally known as pond scum, is in the lab of University of Illinois Cancer Center member Jimmy Orjala, PhD, Professor and Associate Head for Research of Pharmaceutical Sciences at the Retzky College of Pharmacy at the University of Illinois Chicago (UIC).
Using samples collected from diverse environments such as temperate lakes, rainforests, savannas, boreal forests and subtropical wetlands, the Orjala Lab uses them to focus on the discovery of novel anticancer and antimicrobial metabolites from freshwater cyanobacteria using genomic tools, mass spectrometry and spectroscopic techniques.
As of Ocotber 2024, the Orjala Strain Library had 1,528 unique cyanobacteria strains. They isolate their strains from soil and freshwater samples across the country. There are currently 28 states represented in the library, including Alaska and Hawaii. A few of the strains are also sourced from Iceland thanks to a collaboration with the lab of Brian T. Murphy, PhD, Professor of Pharmaceutical Sciences in the College of Pharmacy.
“Cyanobacteria, sometimes called blue-green algae, are a large group of bacteria that are present in nearly every climate and ecosystem on the planet. Unlike most other bacteria, they are photosynthetic. They introduced oxygen into our atmosphere billions of years ago, and it is currently believed that plants used cyanobacteria to develop their ability to photosynthesize,” explains Orjala, who is part of the Cancer Center’s Translational Oncology Research Program.
Additionally, the UIC Strain Library is a vast collection of cyanobacteria collected from freshwater and estuarine environments around the world. Over one hundred strains are added to the library each year.
Discovery
One of the recent discoveries from the Orjala lab was the structures of Aulosirazoles B and C, two structural analogues of the known cytotoxic compound Aulosirazole A. These were discovered from a cyanobacterial strain originally isolated from a soil sample from Iceland.
Aulosirazoles A and B were found to be active against several ovarian cancer cells. They were found to cause the FOXO3a protein, a known tumor suppressor, to accumulate in the nuclei of cancer cells. Once within the nucleus, FOXO3a regulate the transcription of certain genes and prevent further growth of cancer cells. Many tumor cells will activate a pathway which inhibits the FOXO3a translocation to the nucleus and leaving it in the cytoplasm. But when the cells are treated with Aulosirazole, FOXO3a will move to the nucleus again.
“This discovery is very promising for the future of ovarian cancer treatment efforts, and we are hopeful that Aulosirazole’s structure can be used as a new foundation for the development of ovarian cancer drug leads,” Orjala said.