Cervical cancer 'cure' closer with gene-editing breakthrough, scientists say
Updated October 09, 2019 16:14:22
Queensland researchers are hailing a world-first “cure” for cervical cancer, having killed off tumours in mice using CRISPR gene-editing technology.
- Scientists say all the treated mice had a 100 per cent survival rate
- The Griffith University scientists are working towards performing human trials of the gene therapy in the next five years
- Researchers say the breakthrough means other cancers could potentially be treated once scientists knew the right genes to target
“This is the first cure for any cancer using this technology,” Nigel McMillan, the lead researcher and the director of infectious disease and immunology at The Menzies Health Institute Queensland, said.
The scientists used CRISPR-Cas9, a technology for changing the sequence of DNA in cells to correct mutations, to successfully target and treat cervical cancer tumours in mice using “stealth” nanoparticles.
Professor McMillan said it had been a five-year research project, with the nanoparticles used to target a gene called E7 found in cancers caused by the human papilloma virus.
“We would then edit it by introducing some extra DNA that causes the gene to be misread and stop being made,” Professor McMillan said.
The scientists targeted human papillomavirus (HPV)-driven cancers — cervical cancer in this case — and delivered the nanoparticles via injection into live tumour-bearing mice.
“This is like adding a few extra letters into a word so the spell checker doesn’t recognise it anymore,” Professor McMillan said.
“Because the cancer must have this gene to produce, once edited, the cancer dies.
“In our study, the treated mice have 100 per cent survival and no tumours.
“We looked for lots of markers, inflammation and damage, but they were perfectly fine, so this is very exciting.”
‘Very serendipitous moment in science’
Professor McMillan attributed the team’s “lightbulb moment of discovery” to inquisitive student Luqman Jubair, a medic from Iraq who, once qualified, wants to work in genetic therapies in Australia.
“He went away and did something I did not really ask him to do and he added extra treatments [injections] into the regime and it turned out to be the lightbulb moment,” Professor McMillan said.
“Our normal series of three treatments slowed the cancer down, but when he [Dr Jubair] added the extra four after that, it [the tumour] completely disappeared.
“And just as well he did use some initiative, because without him doing that we would probably just have a pretty average outcome where tumours sort of slow down a bit and then keep growing.
“So three was good, but seven was even better — the magic number — it was a very serendipitous moment in science and they do not come along very often.”
‘Imagine the lives this could save’
A breakthrough like this could have changed the life of cervical cancer survivor Jannene McLean.
The 48-year-old was diagnosed 15 years ago, and told she would die without treatment.
“It was quite confronting — those words startled me,” Ms McLean said.
“When I was referred to an oncologist I knew things were in a bad way — it is the big C — I was scared and did not know what to do.
“In the end I chose a radical hysterectomy.”
So at 33, Ms McLean had to make the heart-wrenching decision to not to have children in order to try to save her life.
Ms McLean said this “cure” could have changed her destiny.
“It would have great had it been around when I was a young girl, but it wasn’t,” she said.
“I am really excited this has happened now though — it is a fantastic breakthrough for young women and boys who could have been exposed to HPV.
“It was just not my time, but imagine the lives this could save.”
‘Still many steps to go through’
Professor McMillan said with this breakthrough, other cancers could potentially be treated “once we know the right genes”.
“This is the missing tool kit we have in our gene therapy toolbox,” he said.
Nearly all cervical cancers are caused by a human papillomavirus infection (HPV), with more than 250 women in Australia dying from the disease each year, according to Cancer Australia.
“Persistent infection with high-risk HPV is responsible for 99.7 per cent of cervical cancer cases,” Professor McMillan said.
“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.
“There are still many steps to go through before we get to the clinic stage.
“But I think this really proves that gene editing and CRISPR is going to be proved to be useful in the treatment of not only genetic disorders, but also cancer, so we are very excited about it and this will generate some hype I think.”
The Griffith University scientists are working towards human trials of the gene therapy in the next five years.
The study has been published in the journal Molecular Therapy.
Topics: cervical-and-vulval-cancers, diseases-and-disorders, health, science-and-technology, academic-research, research-organisations, medical-research, griffith-university-4111, qld, australia, brisbane-4000, southport-4215
First posted October 09, 2019 06:43:03