Date: 7th October 2019
Nanoparticles have been used to deliver CRISPR-Cas9 gene editing machinery in mice to eliminate cervical cancer tumours.
Cervical cancer is the fourth most frequent cancer in women with an estimated 570,000 new cases in 2018. In most cases the virus human papillomavirus (HPV) is responsible for cervical cancer, and whilst vaccinations and early screening are available, often the lack of symptoms early in the disease means that patients do not seek medical advice at this crucial stage.
We are starting to realise the enormous potential that gene-editing therapies can bring to the clinic. However, still in its infancy the learning curve is steep, and efficiency and safety concerns are always high on the agenda.
Now scientists from Australia have turned to CRISPR/Cas9 to eradicate cervical cancer by targeting one of two oncoproteins, E7, which is encoded by HPV and is in part responsible for the development of HPV-induced carcinogenesis.
Liposomes are well established as a drug delivery system. In this study researchers from Griffin University, Queensland, used liposomes to encase CRISPR-Cas9 machinery to form ‘stealthy’ nanoparticles.
The nanoparticles were injected into mice cervical cancer tumours and the CRISPR-Cas9 worked by introducing DNA inserts into the HPV gene encoding E7 so that the gene was misread and its production ceased. Incredibly, after injection the tumours were completely eliminated, cell death in the tumour was induced by apoptosis, and 100% of the mice survived.
One of the factors attributed to the success of the treatment was an increased injection regime. Whereas their normal series of three injections decelerated the cancer growth, the increase to seven injections completely eradicated the tumours.
We have already seen the use of CRISPR-derived therapies starting to enter the clinic for treatment of genetic disorders, however this recent advancement provides strong evidence that CRISPR-derived therapeutics could be a very powerful tool in the fight against cancer.
The authors are working towards bringing the breakthrough to human trials in the next few years.
From a safety perspective, the study exploited the fact that cervical cancer is caused by an infectious disease and so the CRISPR-targeted DNA is in fact ‘foreign’. This alleviates the added complication of how to avoid edits on healthy cells.
However, with several viruses, bacteria and even parasites causing or increasing the risk of cancer this really could be a valuable method in finding a cure for at least some cancers. One can only wonder and hope that the efficacy of the treatment which appears so high in mice can be attained once translated into humans.
For a more in depth read from Griffin University please follow the link
Jubair, L., S. Fallaha and N. A. J. McMillan “Systemic Delivery of CRISPR/Cas9 Targeting HPV Oncogenes Is Effective at Eliminating Established Tumors.” Molecular Therapy.