A groundbreaking discovery has been made in the field of childhood leukemia research, and it's a game-changer. The timing of a gene mutation can determine the aggressiveness of leukemia in children, and this finding is set to revolutionize treatment approaches.
Researchers from the Icahn School of Medicine at Mount Sinai have unveiled a critical link between the timing of a leukemia-causing gene mutation and the outcome for children with this disease. Dr. Elvin Wagenblast, an Assistant Professor at the school, led a study published in Cancer Discovery, which sheds light on why children with the same mutation can experience vastly different outcomes.
But here's where it gets controversial: the study suggests that the stage of development when the mutation occurs is a crucial factor. Leukemia that begins before birth tends to be more aggressive, grows rapidly, and is harder to treat. This adds a new dimension to the precision medicine approach for childhood leukemia.
Dr. Wagenblast and his team at the Wagenblast Lab set out to unravel the mystery of how a normal blood stem cell transforms into a cancerous one. They employed cutting-edge CRISPR/Cas9 genome-editing techniques on human primary blood stem cells, modeling different developmental stages of acute myeloid leukemia, a highly aggressive blood cancer.
Using CRISPR technology, the researchers induced the NUP98::NSD1 fusion oncoprotein, a cancer-promoting protein resulting from abnormal gene fusion, into human blood stem cells from various developmental stages, ranging from prenatal to postnatal, adolescence, and adulthood. This created the first humanized experimental model that demonstrated how the same mutation behaves differently depending on when it occurs in life.
The results were eye-opening: stem cells produced during prenatal development easily transformed into leukemia, resulting in a highly aggressive and primitive form of the disease. In contrast, stem cells produced postnatally became increasingly resistant to transformation and required additional mutations to become cancerous. Prenatal-origin leukemia stem cells, abnormal blood stem cells that arise before birth, were more dormant (quiescent) and relied heavily on specific energy sources associated with the cancer state, which were not observed in leukemias that originated later in life.
Despite their dormant state, these prenatal leukemia stem cells are harder to eliminate with standard treatments, explaining why prenatal-origin leukemias behave more aggressively, even with identical genetics.
By analyzing single-cell gene expression data from their models, the investigators identified a prenatal gene signature that can predict whether a child's leukemia likely began before birth. In patients, this signature strongly correlated with significantly worse clinical outcomes.
Dr. Wagenblast emphasized, "This work tells us that age matters at the cellular level. The same mutation behaves very differently depending on when it happens. Understanding this gives us a new way to identify the highest-risk patients and tailor therapies beyond standard genetic classifications."
The team tested therapies against the most aggressive leukemia stem cells and discovered that these cells were particularly vulnerable to venetoclax, a drug already approved by the Food and Drug Administration and used in clinical settings. Venetoclax-based combinations, including with standard chemotherapy, significantly reduced the aggressiveness of leukemia in the experimental models.
Dr. Wagenblast added, "These findings provide clinicians with mechanistic support to use venetoclax combinations in NUP98-rearranged acute myeloid leukemia, especially in younger patients whose disease likely started before birth."
Understanding the timing of leukemia's onset can help doctors choose more effective therapies earlier, reducing the need for trial-and-error approaches and preventing resistance and relapse later on.
This study shifts the scientific understanding of childhood cancer. The developmental timing of the first mutation is not a minor detail; it fundamentally shapes disease biology, treatment resistance, and relapse risk.
The research opens doors to new diagnostic tools that can identify prenatal-origin leukemias, venetoclax-based combination therapies that precisely target vulnerable leukemia stem cells, and clinical trials that incorporate developmental timing into risk assessment.
The team's next step is to develop therapies that directly target the unique metabolic program of prenatal-origin leukemias, aiming to selectively eliminate leukemia stem cells while sparing healthy blood stem cells.
This study was conducted in collaboration with Fred Hutchinson Cancer Center, Children's Hospital of Philadelphia, and Cincinnati Children's Hospital, with funding from the National Institutes of Health and private foundations.
