Inspired by a chemical that fungi secrete to defend their territory, MIT chemists have synthesized and tested several dozen compounds that may hold promise as potential cancer drugs.
A few years ago, MIT researchers led by associate professor of chemistry Mohammad Movassaghi became the first to chemically synthesize 11,11'-dideoxyverticillin, a highly complex fungal compound that has shown anti-cancer activity in previous studies. This and related compounds naturally occur in such small amounts that it has been difficult to do a comprehensive study of the relationship between the compound's structure and its activity - research that could aid drug development, Movassaghi says.
"There's a lot of data out there, very exciting data, but one thing we were interested in doing is taking a large panel of these compounds, and for the first time, evaluating them in a uniform manner," Movassaghi says.
In the new study, recently published online in the journal Chemical Science, Movassaghi and colleagues at MIT and the University of Illinois at Urbana-Champaign (UIUC) designed and tested 60 compounds for their ability to kill human cancer cells.
"What was particularly exciting to us was to see, across various cancer cell lines, that some of them are quite potent," Movassaghi says.
Lead author of the paper is MIT postdoc Nicolas Boyer. Other authors are MIT graduate student Justin Kim, UIUC chemistry professor Paul Hergenrother and UIUC graduate student Karen Morrison.
Improving nature's design
Many of the compounds tested in this study, known as epipolythiodiketopiperazine (ETP) alkaloids, are naturally produced by fungi. Scientists believe these compounds help fungi prevent other organisms from encroaching on their territory.
In the process of synthesizing ETP natural products in their lab, the MIT researchers produced many similar compounds that they suspected might also have anti-cancer activity. For the new study, they created even more compounds by systematically varying the natural structures - adding or removing certain chemical groups from different locations.
The researchers tested 60 compounds against two different human cancer cell lines - cervical cancer and lymphoma. Then they chose the best 25 to test against three additional lines, from lung, kidney and breast tumors. Overall, dimeric compounds - those with two ETP molecules joined together - appeared to be more effective at killing cancer cells than single molecules (known as monomers).