Research leaders at the Wistar Institute say that their work points the way to the development of a new generation of cancer drugs.
Dr. Qihong Huang, co-senior author of the study, says that the group has identified a small molecule that blocks the pathway of a particular miRNA, called miR-21, which is implicated in brain cancer, as well as lung, colon, breast, and ovarian cancer.
He believes that with further development, the molecule has the potential to boost patient response to existing chemotherapies, as well as to become a stand-alone cancer drug.
Highlighting the fact that miRNAs represent a largely unexplored class of targets for the development of therapeutics and diagnostics, Huang says: "This is a totally novel target. It's very understudied, and still in its infancy, but its potential is tremendous. Because miRNAs have the ability to shut down genes and prevent their expression, they may ultimately provide a target for therapies that are more selective than conventional chemotherapy drugs and have fewer side effects."
The researcher, who is an assistant professor in Wistar's Molecular and Cellular Oncogenesis Program, says that one sizeable hurdle in harnessing the power of miRNAs is getting "the right molecule into the right place at the right time" to regulate their function.
"In terms of developing therapeutic agents for cancer, for example, we need to identify small molecules that can get into the bloodstream and get into the cells. The problem is, to date, no one had been able to show that such miRNA inhibitors exist," he says.
Huang claims that his group has now developed a method to identify inhibitors of miRNA pathways in live human cells.
According to him, preliminary data from the ongoing studies suggest that the inhibitor can be used in combination with other chemotherapy drugs to provide a synergistic effect.
He and his colleagues are now conducting studies in mice to assess the inhibitor's effectiveness against brain, breast, and colon tumours.
The researchers are also working to modify the molecule to make it even more efficient.
Huang says that his team's screening test provides a unique tool that can be used to advance investigations of miRNAs, and their involvement in various diseases
"The cell-based assay that we have established can potentially be used to screen for additional small-molecule inhibitors that can block miRNA," he says.
A research article describing the study has been published in the journal Angewandte Chemie.