Scientists at the German Cancer Research Centre (DKFZ) and Heidelberg University Hospital were able to delay the development of cancer which has been hailed as an important milestone. According to the study, the mice with a hereditary predisposition to colon cancer survived significantly longer than those who were unvaccinated.
Alongside an anti-inflammatory preparation, the protective effect of the vaccination increased even further.
Microsatellite instability (MSI) in tumours can arise spontaneously or as a result of a hereditary predisposition, known as the Lynch syndrome.
Around a quarter of MSI colon tumours are caused by this syndrome and around half of those affected will develop cancer at some point in their life.
The team’s research has been able to show that identical mutations and that identical neoantigens occur in the tumour in many patients with Lynch syndrome.
Magnus von Knebel Doeberitz, who heads a department at both the Heidelberg University Hospital and the DKFZ, said: “We have also seen in unvaccinated Lynch mice that the immune system is active against the four neoantigens.
“Our vaccination strengthens an already existing natural immune reaction against the cancer cells.”
Matthias Kloor, who heads research on preventive vaccinations for Lynch syndrome, added: “We, therefore, wanted to test whether such frequently occurring neoantigens are able to act as a protective vaccine to activate the immune system against the tumour cells and thus prevent cancer from developing.”
He continued: “For the first time, we were able to demonstrate in a living organism that vaccination with neoantigens protects against cancer.
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The team examined a strain of mice that developed colon cancer as a result of a defect in the DNA repair enzymes – comparable to people who suffer from Lynch syndrome.
The ‘lynch mice’ developed tumours in the intestine from the age of six months and die from them a few weeks or months later.
A special algorithm predicted which of these neoantigens could trigger a strong immune response in the mice.
Finally, four vaccine peptides were selected for the experiments.
The vaccinated mice survived an average of 351 days, while the unvaccinated animals only survived 263 days.
The tumour mass was also significantly lower in the vaccinated animals.
If the mice received the drug naproxen in addition to the vaccination, this further increased the preventive effect of the vaccination.
Naproxen is an anti-inflammatory and pain reliever that, like aspirin, belongs to the group of non-steroidal anti-inflammatory drugs (NSAIDs).
Active ingredients from this group are already recommended in some countries for the chemoprevention of colorectal cancer in patients with Lynch syndrome.
Addtional reporting by Monika Pallenberg
Published at Fri, 30 Jul 2021 11:05:49 +0000