An international team of researchers with Spanish participation has discovered how some gliomas -one of the most common types of brain tumor- manage to avoid chemotherapy and acquire resistance in front of it.
The work, whose conclusions are published in Nature CommunicationsIt has been carried out by scientists from the National Cancer Research Center (CNIO), the Hong Kong University of Science and Technology and the Beijing Neurological Institute.
The CNIO team has been led by the Italian scientist Massimo Squatrito, head of the Brain Tumors Group of the Seve Ballesteros Foundation of this center, who has underlined the important advance that this discovery represents to understand why some brain tumors generate resistance to chemotherapy and improve treatments.
Currently, the main, and almost the only, treatment for gliomas is the combination of radiation therapy with the chemotherapy agent called temozolomide, a strategy that can extend the survival of these patients by up to 30%.
However, almost half of patients with this type of tumor (between 40 and 50%) are resistant to temozolomide and the tumor continues to grow even though they are under treatment.
Researchers have discovered in this work that a group of patients acquires a specific genetic alteration who can evade that combination therapy.
The team from the Hong Kong University of Science and Technology validated the presence of these “rearrangements” in a subtype of a large cohort of recurrent tumors from different hospitals, mainly from the Beijing Tiantan Hospital.
Using genomic editing techniques, the CNIO researchers replicated some of these translocations in different animal and cell models and thus confirmed that may become resistant to temozolomide.
“It seems that translocations are not present in the original tumor, only in recurrent tumors, those that arise after the original cancer is treated,” Squatrito said in a press release released by the CNIO, clarifying that this Resistance to chemotherapy can occur as a consequence of the treatment itself.
The find may lead to changes in the methods by which it is monitored The efficacy of the therapy, according to the researchers, who have explained that if the finding that has already been verified in animals is confirmed in patients, it could become an important tool for the early detection of this resistance.
“Through a simple liquid biopsy analysis with just a few blood samples, we could find out which patients are developing resistance to temozolomide and will help switch to other therapeutic options, when they are available, “said Massimo Squatrito.
In future research steps, the team will try to identify new forms of treatment for temozolomide-resistant patients.
The work has been funded by the Carlos III Health Institute, the Seve Ballesteros Foundation, the Spanish Association Against Cancer (AECC), the Natural Science Foundation of China, the Research Grants Council of Hong Kong, the Beijing Municipal Administration of Hospitals, the Beijing Nova Program and the Beijing Talents Foundation.