MOSCOW, July 26, Tatyana Pichugina. More than half of malignant brain tumors are glioblastomas. This is a fast-acting aggressive disease that does not leave a person a chance to live for at least a couple more years. Russian scientists are working in several directions at once to give hope for a cure.
Amazes the entire brain
Gliomas are malignant tumors that form in the brain and spinal cord, in glial cells. Their most aggressive stage is glioblastoma.
«She has a very poor prognosis. Despite treatment, on average, patients live for about 15 months,» says Ph.D. Medical Sciences Anastasia Ryabova.
Glioblastoma grows literally in two or three months, so there is no screening for its early detection. Neurological symptoms: headache, convulsions, movement disorders, loss of coordination.
«It looks like a stroke. Often they are treated for it, and then it turns out that the patient has a tumor,» the doctor notes. -type=»photo» data-crop-ratio=»1″ data-crop-width=»600″ data-crop-height=»600″ data-source-sid=»cc_by_40″ class=»lazyload» width=» 1920″ height=»1920″ decoding=»async» />
A person is sent for an MRI and, if suspicions are confirmed, an operation is prescribed. The final diagnosis is based on the results of a biopsy with genetic studies. Then — chemotherapy and radiation therapy. But the disease quickly returns.
«The fact is that glioblastoma is not a local tumor, it spreads diffusely. Some of its cells are even in the other hemisphere, so there may be distant relapses. Cured in one place, but she progressed in another way,» Anastasia Ryabova explains.
The last chemotherapy drug effective for glioblastoma was registered two decades ago. Since then no progress. Fundamentally new approaches are needed that will not only significantly prolong the life of the patient, but also support his ability to act.
«A tumor in the brain reduces the quality of life and relatives of patients. Often they have to quit their jobs to care for a loved one,» the expert clarifies .
Unique Patient
The five-year threshold of survival for glioblastoma is overstepped by units. One of them is Maria Yurova. In 2017, she removed the tumor, but it immediately began to grow again. When they tried all the methods of treatment, the young woman turned to the N. N. Petrov National Medical Research Center of Oncology in St. Petersburg, where they are engaged in immunotherapy of brain tumors.
This is an experimental, patient-specific approach to enhance the T-cell response. Simply put, the body itself begins to destroy the malignant formation. Immunotherapy is also called a cancer vaccine. Maria underwent several courses of treatment and continues to fight the disease.
Viruses against cancer
One of the promising approaches is the use of oncolytic viruses capable of destroying cancer cells. At the Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, together with the State Scientific Center «Vector» and the company «Oncostar», they created a drug that received permission for clinical trials. people on the planet.
“We tweaked the virus a little by cutting out the growth factor and thymidine kinase genes. Without them, it lost the ability to multiply in any cells except cancer cells, and weakened by about 200 times,” says Vladimir Richter, head of the biotechnology laboratory of the ICBFM SB RAS, candidate of biological sciences . Unlike healthy cells, cancer cells have a strong metabolism, there are enough active enzymes for virus reproduction.
In 2021, the drug began to be tested on patients in the terminal stage of breast cancer at the N. N. Petrov National Medical Research Center of Oncology. Research is currently ongoing at four medical centers. About 30 people participate in them. Complications have not yet been found.
It turned out that the drug effectively inhibits the growth of brain tumor cells. Already this year, scientists plan to start clinical trials of a drug for the treatment of gliomas.
In the world, only one drug based on an oncolytic virus, Imlygic, has been approved for the treatment of melanoma. It's herpes simplex virus type I. Japan approved a similar treatment for gliomas late last year. =»0.983739837398374″ data-crop-width=»600″ data-crop-height=»590″ data-source-sid=»» class=»lazyload» lazy=»1″ />
Right on target
«Any malignant neoplasm arises from a single precursor cell. At some point, a genetic breakdown occurs, which causes the cell to divide indefinitely and quickly,» says the head of the laboratory for primary bioscreening, cell and gene technologies of Ural Federal University (created under a mega-grant from the Ministry of Education and Science of Russia) candidate Medical Sciences Vsevolod Melekhin. The fact is, he adds, that there are two systems in the cell: one stimulates growth, the other, on the contrary, inhibits it. If the balance is disturbed, a malignant tumor is formed.
«Glioblastoma originates in glial cells — astrocytes. Molecular changes in them cause rapid growth, proliferation and spread of the tumor. The focus spreads to the surrounding tissues. This can be seen on MRI,» the researcher continues.
Localization complicates the diagnosis and treatment of glioblastoma. You cannot cut off too much surgically, because you will damage the brain tissue. Due to the blood-brain barrier, not all chemotherapy is suitable. We need special low-molecular compounds that will penetrate the brain from the bloodstream. They are synthesized by chemists, and bioinformaticians are looking for those that affect the tumor, and selectively, without affecting healthy tissues.
it will kill tumor cells and not harm others. This is one of the areas of drug development,” Vsevolod Melekhin clarifies.
Thousands of compounds have already been tested in his laboratory and two dozen very promising ones have been found. Five are tested in cell cultures. If the results are good, they will move on to experiments with laboratory animals. 0.753333333333333″ data-crop-width=»600″ data-crop-height=»452″ data-source-sid=»cc_by-sa_30″ class=»lazyload» width=»1920″ height=»1446″ decoding=»async » />