Enoxacin stimulates the activity of micro-RNA molecules, which inhibits the growth of tumours. This finding opens the door to new drugs that could revolutionize cancer treatment.

The research study - coordinated by Manel Esteller of the Bellvitge Biomedical Research Institute (IDIBELL) - has identified a substance that inhibits cancer growth by activating micro-RNA molecules and the so-called ‘dark genome’ or non-coding DNA. The study appears this week in the prestigious scientific journal Proceedings of the National Academy of Sciences (PNAS).

The human body cells have a genome - the set of our DNA - encoding our proteins such as keratin in the skin or blood haemoglobin. This genome with encoding DNA only represents the 5% of our genetic material. The remaining 95% is known as the ‘dark genome’ or non-coding DNA and its role is largely unknown. Part of this DNA produces small molecules called micro-RNAs that activate or deactivate genes. In recent years it has been shown that alterations in these molecules are involved in tumour formation.

Researchers have shown that the small molecule enoxacin, which is used in antibacterial compounds, binds to the protein that builds the micro-RNAs and stimulates their inhibitory activity of the tumour growth. According to researcher Manel Esteller "it is like if we have a second hand car and we put an engine in it just out of the factory. It has been tested both in laboratory cells and in animal experimental models and now its behaviour should be studied in humans.” These were the words of Esteller, who pointed out that the advantage of this compound is its well-known metabolism and human security.

Esteller added that "although the use of this molecule may not get approved in cancer treatment, this finding opens the door to design new drugs that use micro-RNAs as a therapeutic target. We show the pharmaceutical industry a new direction where to direct their efforts in the anti-tumour therapy."