Highlighted during the Covid-19 pandemic, mRNA had already been studied for several years to fight cancer, and more studies are underway on the topic.
Messenger ribonucleic acid, better known as messenger RNA or mRNA. This term became very popular with the Covid-19 pandemic, because it is the name of the molecule that made it possible to quickly create effective vaccines against this virus, which spread in a matter of weeks on the planet.
But before it was used against SARS-CoV-2, messenger RNA had already been studied for several years and was especially considered as a potential treatment against cancer. The pandemic has had the positive side effect that the laboratories can come forward more quickly with this subject.
The American laboratories Moderna and Merck announced last Wednesday that they had entered into an agreement to jointly develop and market an mRNA vaccine against skin cancer. The heads of BioNTech, for their part, have raised the possibility that an mRNA vaccine against cancer will be available “before 2030”.
What is messenger RNA again?
mRNAs “serve as a pattern during the production of proteins”, explains Inserm. These molecules are produced from our DNA, it is “a photocopy of the side of the genome where the instructions for making a given protein are written”. An mRNA is therefore, in a sense, a blueprint that is transferred to a cell, which will tell it how to produce the protein it needs.
In the context of vaccines against Covid-19, an mRNA encoding the Spike protein was used and injected because it is this protein that allowed the virus to enter our cells.
After the vaccine, with the plan provided by the mRNA, “our cells then produce this protein and ‘present’ it on their surface. The immune system recognizes it as if it were carried by the virus itself and activates the defense mechanisms and memory response”, explains Inserm. The immune system will therefore be able to recognize the virus if the organism is infected in the future.
Same technique as against Covid-19
When we talk about an mRNA vaccine against cancers, we are not only talking about preventive techniques, as is the case with Covid-19, but also about curative methods: it is not a matter of preparing the system for a potential infection, the disease is already there, and it must be fought.
But mRNA remains used according to the same principle: “to ensure that representative samples of cancer cells are exposed to immune cells”, explains the ARC Foundation for cancer research.
“We take cells from the tumor and we will study the sequences, that is the identity map of these tumors”, explains Alain Ducardonnet, cardiologist and health consultant for BFMTV.
“We will then synthesize the mRNA and we will inject it into the body and there we will somehow give the information to the immune cells to specifically attack the images that the mRNA brings. So they will specifically attack the tumor cells .”
Cancer harder to perceive
The whole difficulty with cancer lies in finding the protein that must be reproduced in order to fight the tumor. Viruses are thus “carriers of certain properties which indicate to the immune system that they are enemies”, explains ARTE Mustafa Diken, immunologist.
But “cancer is different because cancer cells come from our own cells, and normally the immune system cannot always identify at first glance that it is an enemy,” he explains.
Indeed, it is necessary “to ensure that this targeting cannot set the immune system against healthy cells that would also express the protein encoded by the vaccine’s mRNAs”, emphasizes the ARC Foundation. The researchers are therefore trying to target “some of the genetic mutations found in cancer cells” which “directly affect the nature of the proteins produced by these cells.”
On the other hand, each cancer acts differently and affected individuals have a different immune response, leading to a need for personalized responses.
mRNA associated with other methods
Several dozen studies are currently underway on the subject, as the pandemic has brought the mRNA method to light and increased the number of funds allocated to it.
“Some RNA drugs under development are designed to directly target the fundamental processes of cancer: proliferation, acquisition of resistance to treatment, formation of metastases, etc.,” explains the League Against Cancer, “others rather aim at the permissive environment that supports the development of cancer and works, for example, by activating the anti-cancer immune response.”
It is still very difficult at the moment to give the release date of a treatment and mRNA, although revolutionary in its approach, is not a miracle answer and may not be enough by itself. Immunotherapies “can therefore naturally be linked to possible vaccine strategies in the long term. They are also already integrated in current vaccination trials against cancers”, writes the Arc Foundation.
In addition to cancer, treatments using mRNA “can allow the personalized management of a wide range of diseases, such as genetic diseases in particular”, explains Palma Rocchi, biologist, director of research at Inserm. “It is a real revolution for tomorrow’s medicine.”