Researchers from St Jude Hospital in the US have identified an important member of a chemical family that targets a protein known to cause cancer in childhood.

The chemical is the first small-molecule inhibitor to target the MDMX protein, which is linked to the childhood eye tumoru retinoblastoma as well as certain cases of breast, lung, prostate and other cancers.

During a study, St Jude researchers reported that the newly identified compound SJ-172550 showed some ability in nullifying the effects of MDMX and MDM2, proteins that promote tumour progression by binding and suppressing p53, an important regulator of unchecked cell division.

According to lead researcher Michael Dyer, evidence suggests SJ-172550 works by binding in a reversible manner to a pocket in the MDMX molecule.

“With SJ-172550 sitting in the pocket, the p53 protein cannot bind to MDMX, allowing p53 to do its job and eliminate tumour cells,” Dyer said.

Researchers have, however, warned that several years of detailed chemical studies and additional work are likely to be needed before SJ-172550 can be ready for human trials.

The compound was identified from a chemical library of nearly 300,000 compounds using high-throughput screening. Investigators searched for molecules likely to block MDMX activity.