By combining a specific DNA target with a nanosystem, researchers have identified a potential drug molecule that can inhibit the growth of colon cancer cells1. This technique provides a way to screen potential drugs for a target DNA without complex procedures.

The human genome contains four-stranded DNA structures known as G-quadruplexes. These DNA sequences regulate the activities of cancer-causing genes and have recently emerged as drug targets.

To devise a technique for discovering anticancer drugs, scientists led by Jyotirmayee Dash from the Indian Association for the Cultivation of Science in Kolkata, India deposited a specific four-stranded DNA target on a gold-coated magnetic nanoparticles. They then exposed this nanosystem to a pool of small molecule fragments.

From the pool of reactive fragments, the nanosystem helped synthesize small molecules that selectively bound to the DNA target. This screening helped to identify a few potent molecules whose anticancer potential was explored by exposing them to various cancer cells.

The most potent small molecule was able to reduce the expression of c-MYC gene which has been found to trigger unbridled growth of breast, colon and lung cancer cells. This molecule efficiently killed colon cancer cells.

“Besides DNA, this technique could be used to screen potential drugs for other targets such as proteins and RNA,” says Dash.