Laboratory experiments in human breast cancer cells suggest that the compound inhibits the constant activation of a protein called Stat3 that is found in several different types of cancer, including cancer of the breast, lung, prostate, head and neck, skin, pancreas and ovaries as well as lymphoma and certain kinds of leukemia.
Stat3 is constantly activated in about 60 percent of breast tumors, said Jiayuh Lin, the study's lead author and an associate professor of pediatrics at Ohio State University.
All cells contain Stat3 protein, but in normal cells, Stat3 activities are only turned on temporarily. Researchers do know, however, that Stat3 is constantly turned on in certain tumor cells.
"The cancer cells we studied seem to depend on Stat3 for survival," said Lin. "When we blocked the chain of events that activate Stat3, the cancer cells died."
Lin is also a member of Ohio State's Comprehensive Cancer Center and an investigator in the Center for Childhood Cancer at Columbus Children's Research Institute. He co-authored the study with Shaomeng Wang, Hui Song and Renxiao Wang, all with the University of Michigan Comprehensive Cancer Center.
The researchers named the compound STA-21. They tested STA-21 after using a computer program to narrow down a list of potential compounds to a manageable number that they could physically test in the lab.
When the computer screening process ended, the researchers tested the 100 top compounds. They tested these compounds on human breast cancer cells in order to find which one best stopped the constant Stat3 activation. STA-21 appeared to be the best inhibitor of Stat3 activity.