25 Septembre 2025
In collaboration with the International Agency for Research on Cancer (IARC), scientists have uncovered how certain environmental and lifestyle factors that occur during pregnancy or early life may leave chemical tags on a child’s DNA, potentially shaping the risk of developing acute lymphoblastic leukaemia (ALL), the most common cancer type in children. The study is published in the International Journal of Cancer.
The tags, known as DNA methylation marks, act like on–off switches that control how genes work, without changing the genetic code of the DNA itself. The researchers also introduced a novel concept they call “navigator” methylation. Unlike “driver” methylation changes, which directly affect cancer-related genes, navigator changes triggered by certain exposures may spread across other parts of the genome and create broader methylation shifts that can steer biological pathways towards disease development.
The scientists found that specific DNA methylation changes associated with maternal exposure to radiation, maternal intake of alcohol, and maternal levels of folate may contribute to the development of ALL in children. Some changes, particularly those related to maternal folate levels, were consistent across many leukaemia subtypes and may influence both driver and navigator methylation. Other exposure-related changes appeared to contribute only to navigator methylation and/or showed up only in certain leukaemia subtypes.
Although more research is needed to prove cause and effect, this study adds an important piece to the puzzle of how environment and biology interact to shape the development of childhood cancer through epigenetics. Unlike genetic mutations, epigenetic changes do not alter DNA itself and are potentially reversible, which offers real hope for prevention strategies, early interventions, or future therapies aimed at resetting harmful DNA switches. By highlighting which exposures are linked to which epigenetic marks and leukaemia subtypes, the study helps to identify potential targets for medical action and future health strategies.
Saville JR, Russell LJ, Padget K, Ghantous A, Nordlund J, McKay JA
The potential role of environmentally associated DNA methylation in childhood acute lymphoblastic leukaemia subtypes
Int J Cancer. 157(8):1600–12;
https://doi.org/10.1002/ijc.35506
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