Toulouse researchers have identified and filmed the HEV blood vessels used by T lymphocytes to enter the tumor and destroy cancer cells.
They demonstrated in a clinical trial with 100 patients that the more these vessels there were, the greater the response to immunotherapy.
In the laboratory, they have developed a treatment to multiply these vessels.
At first, it was an intuition, before becoming a hypothesis and recently a reality.
Researchers from Toulouse have in fact just proved that somewhat special blood vessels, baptized HEV, are the blood highways that allow lymphocytes that kill cancer cells to reach the tumor.
These white blood cells are a bit like security guards that patrol our body to protect us from the cancer cells they detect.
For several years, immunotherapy has been used to activate the immune system of these T lymphocytes. A treatment that has enabled many patients condemned by stage 3 or 4 cancer to be able to survive.
But until now it was unclear how these cancer cell killers made their way to tumours.
The more vessels, the better the treatment works.
“We have identified these HEV vessels as the gateways for lymphocytes into tumors during immunotherapy treatment, and even before treatment.
We have succeeded in filming, with very sophisticated microscopy techniques, these lymphocytes which roll, which stop and slip through the vessel to enter the cancerous tumour”, explains Jean-Philippe Girard, Inserm research director at the Institute of Pharmacology and Structural Biology (CNRS/Toulouse III University – Paul-Sabatier) which has just published the results of its research in the journal
Cancer Cell
.
Once they figured out which route these "killer" white blood cells were taking, they set out to find out what their role was in the effectiveness of immunotherapy treatment.
They therefore conducted a clinical study with a hundred patients with melanoma and followed by Professor Caroline Robert, head of the dermatology department at the Gustave-Roussy cancer treatment center in Villejuif.
A biomarker to predict
They scrutinized the sections of tumors made thanks to the biopsies and they counted the number of small HEV vessels which were there.
“We observed that when there were many HEV vessels in the metastases, the patients responded better to immunotherapy and they had a longer survival.
It's very clean.
The HEV vessels are really associated with the response to immunotherapy”, continues the researcher.
Real biomarkers, these vessels are a way for oncologists to predict whether their patients will respond well to combined immunotherapy.
Because this treatment, if it is very effective and makes it possible to offer 50% survival to those who benefit from it, it is also very toxic and has many side effects which can be fatal.
A way to boost the number of HEV ships found
An important advance therefore for the therapeutic choices of oncologists. Which could in a few years also boost their chance of success thanks to another discovery by Jean-Philippe Girard's team. This has indeed succeeded in the laboratory in finding a way to boost the number of HEV vessels, and thus multiply the entry points for the T lymphocytes to go and destroy the tumours.
“We have developed an antibody-based treatment, it is a proof of concept, not yet tested in patients.
But we managed to change the proportion, we increased the number of vessels by 50%, but that was enough to increase the effectiveness of the immunotherapy and that caused the tumors that normally did not regress to regress,” says the researcher. who tested it on breast, colon and fibrosarcoma cancers.
A new discovery that gives hope to further improve the care of patients with cancer, which affects 382,000 new people each year and is the cause of the death of 157,400 patients, the leading cause of death in France.
Health
World Cancer Day: Symptoms, “routine” screening… How were you diagnosed?
Health
Cervical cancer: Screening and vaccination still need to progress
Cell
Tumor
Toulouse
Health
Cancer
Research
Processing
0 comment
0 share
Share on Messenger
Share on Facebook
Share on Twitter
Share on Flipboard
Share on Pinterest
Share on Linkedin
Send by Mail
To safeguard
A fault ?
To print