VANCOUVER — As a man’s cells grew cancerous, a wide range of mutations gradually emerged too, a new gene sequencing study finds. The results provide a deep understanding of the genetic changes that allowed an aggressive form of leukemia to set in and take hold in one patient, Elaine Mardis of Washington University in St. Louis said in a March 28 presentation at the annual conference on Research in Computational Molecular Biology.
“Cancers’ origins lie in the genome,” Mardis said. “These genetic approaches are really addressing the underlying questions of cancer biology.”
In the new study, Mardis and her colleagues collected cells from a 68-year-old man with a blood disease called myelodysplastic syndrome. About one in four people with this disorder go on to develop a fast-moving and dangerous type of cancer called acute myeloid leukemia. Two years after those samples were taken the man was diagnosed with full-blown acute myeloid leukemia, and the researchers harvested a second batch of cells. By reading the letter-by-letter DNA sequences in the two samples of cells, the team could pinpoint genetic changes as the cells turned cancerous.
Over time, the cells accumulated new genetic mutations, the team found. The early mutations didn’t seem to run rampant and overtake all of the cancerous cells, but they didn’t disappear, either. These early mutations became present in less and less of the cancer-cell population.