The majority of chemotherapeutic drugs can be divided in to, alkylating agents, antimetabolites, anthracyclines, plant alkaloids, topoisomerase inhibitors, and antitumour agents. All of these drugs affect cell division or DNA synthesis and function in some way.
But despite chemotherapy being individually tailored, side effects can often cause more pain and discomfort than the cancer itself. Chemotherapy can also increase the risk of cardiovascular disease and occasionally lead to secondary cancer.
Researchers at the University of Illinois at Chicago College of Medicine believe that the FoxM1 gene plays a major part in cancer cell proliferation as well as turning off genes that block proliferation.
It is this gene that the researchers think the anti-cancer agent siomycin A acts upon, without affecting other cell functions, a crucial factor if side effects are to be minimised.
In order to discover this molecule that displays such characteristics, the scientists had to developed a new screening system, based on a naturally fluorescent protein called luciferase, to identify small molecules that inhibit proteins that turn genes on and off.
In further experiments in tissue cultures, the researchers found that siomycin A induced cancer cells, but not normal cells, to commit suicide in a process called apoptosis.
The new screening technique, said Andrei Gartel, assistant professor of medicine and of microbiology and immunology at UIC and principal investigator on the study, gives researchers a rapid way to find agents that target genes believed to cause cancer.
He said siomycin A, the first compound found with the method "is particularly promising because we know that it is not toxic."
The next step now is for Siomycin A to be tested against other cell lines in the laboratory and in preliminary animal experiments before human trials could be planned.
Only a tiny fraction of promising candidate drugs enter clinical trials, and few of those are ever approved.
Their findings appear in the Oct. 1 issue of Cancer Research.