London: Scientists have discovered a way to shrink tumours in certain cancers – a finding that provides hope for new treatments.
The cancers in question are those caused by a new class of genes known as ‘microRNAs’, produced by parts of the genome that, until recently, were dismissed as ‘junk DNA’.
The current finding identifies one particular microRNA (microRNA 380) that appears to disable the king of tumour suppressors, the P53 gene. In order for a cell to become cancerous, P53 must either be mutated or otherwise disabled.
For the research, Australian and American scientists studied neuroblastoma, a childhood cancer of the nervous system in which 99pc of patients do not have mutations of the P53 gene.
Dr Alex Swarbrick, from Sydney’s Garvan Institute of Medical Research, Dr Susan Woods from Brisbane’s Queensland Institute of Medical Research and Dr Andrei Goga from The University of California San Francisco found instead that neuroblastomas disable p53 by over-producing microRNA 380. When they blocked the microRNA, P53 production resumed, cancer cells died and tumours became much smaller.
“The revolutionary thing about this finding is that it’s the first time anyone has blocked the growth of a primary tumour by the simple delivery of a microRNA inhibitor,” said Alex Swarbrick, from Sydney’s Garvan Institute of Medical Research.
“By that, I mean we delivered the microRNA inhibitor in a way we might give it to a person – as a twice-weekly injection – not using some genetic trick. It’s the closest thing to a clinical result that’s yet been published. That, of course, makes this microRNA a potential therapeutic target for all cancers that depend on it,” he added.
The results are reported in the prestigious international journal Nature Medicine, online today.