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26. Feb. 2026
An international research team led by Marek Mráz from CEITEC Masaryk University and University Hospital Brno has described what happens inside tumour cells when a slow-growing lymph node cancer transforms into an aggressive form of the disease. The key lies in the loss of a molecule called miR-29, which normally acts as a brake on tumour cell growth. Measuring its levels could help doctors identify high-risk patients early and better predict how the disease will progress.
Follicular lymphoma is a type of malignant cancer arising from immune cells in the blood. It typically grows slowly at first, but in approximately one in five patients it can, over time, suddenly transform into a rapidly progressing tumour with a significantly worse prognosis. This transition (known as histological transformation) is crucial for treatment decisions and overall outlook. The research team investigated which processes occur in tumour cells during this change. They compared samples from the same patients before and after transformation to the aggressive phase. The analysis focused not only on protein-coding genes, but also on small regulatory molecules known as microRNAs, which fine-tune the production of proteins from other genes.
“We found that at the moment the disease begins to transform into an aggressive form, levels of miR-29 drop sharply. This small regulatory molecule normally functions as a natural brake on tumour cell growth. Its loss gives tumour cells an advantage – they become more responsive to signals promoting their proliferation and better able to adapt to changes in the tumour microenvironment,” explains the study’s first author, Daniel Filip. Without this “brake”, tumour cells multiply more rapidly and survive more effectively.
The research does not only deepen understanding of tumour biology; it also opens a concrete opportunity to improve patient care. In a large cohort of 185 patients, the scientists demonstrated that those with low miR-29 levels had a worse clinical course. The amount of this and other microRNA molecules may therefore help predict in advance which patients are at higher risk of rapid disease progression.
These findings were confirmed in an independent group of patients treated within the American clinical trial SWOG. The South West Oncology Group (SWOG) is one of the largest oncology research consortia in the United States, organising large-scale clinical studies. For the first time in its history, SWOG provided clinical samples for analysis in the Czech Republic – specifically to the Brno research team. This allowed the scientists to validate their conclusions using real-world clinical data.
“We are able to measure microRNA levels – including miR-29 – even in routinely stored tumour tissue samples. This is crucial, as such a test could be relatively easily implemented in clinical practice. In the future, it could serve as a simple risk indicator and help physicians decide which patients require closer monitoring or more intensive treatment,” says Marek Mráz.
The team is already working on the development of such a diagnostic tool. The preparation of a prognostic test based on microRNAs as biomarkers was also the focus of Daniel Filip’s project within the Life Science Transfer Academy programme, organised by the innovation agency JIC in cooperation with CEITEC MU and the Faculty of Medicine, Masaryk University.
In addition to CEITEC MU and University Hospital Brno, the research involved experts from other Czech institutions as well as partners in Europe and the United States. The study was published in Leukemia, one of the top five journals in its field.
Marek Mráz’s research group is part of the National Institute for Cancer Research (NICR).
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