Genome-editing study raises hopes for 'curing' cervical cancer

Australian researchers have successfully halted and eliminated cancer growth in tumour-bearing mice by injecting them with nanoparticles containing genome editing machinery targeting cancer genes.

'This is the first cure for any cancer using this technology,' said Professor Nigel McMillan, programme director at the Menzies Health Institute Queensland, Griffith University, who led the study.

'The nanoparticles search out the cancer-causing gene in cancer cells and "edit it" by introducing some extra DNA that causes the gene to be misread and stop being made,' he added.

In the study published in Molecular Therapy, the researchers used CRISPR/Cas9 genome editing technology to prevent the expression of a human papillomavirus (HPV) gene, called E7, that drives cervical cancer.

The CRISPR/Cas9 machinery was packaged into stealth nanoparticles and injected into mice with tumours that developed following transplantation with HPV cervical cancer cells. Mice that were transplanted with HPV-16 cervical cancer cells received three injections at 8, 12 and 16 days. The researchers observed that tumour growth was halted in these mice after 77 days and they out-lived untreated mice.

They also treated mice that were transplanted with HPV-18 cervical cancer cells with nanoparticles targeting the E7 gene. These mice were separated into two groups; one group received three injections whereas the other group received seven. Their findings show that tumour growth was temporarily halted but resumed again in the mice that received three injections. However, the tumours were completely cleared in mice that were injected at seven different time points.

These findings suggest that CRISPR/Cas9 therapy may be an effective treatment for cervical cancer, however further studies need to be carried out to determine the specificity and safety of this treatment before it can be trialled in humans.

'We know a third of all cancers in the world are caused by infectious organisms, so this treatment would be fantastic because we are targeting foreign genes, genes that are not normally in our genome,' Professor McMillan told ABC News.

'There are still many steps to go through before we get to the clinic stage,' he added.